dc_context_t Class Reference

An object representing a single account. More...

#include <deltachat.h>

Public Member Functions
void	dc_accept_chat (dc_context_t *context, uint32_t chat_id)
	Accept a contact request chat.
int	dc_add_address_book (dc_context_t *context, const char *addr_book)
	Add a number of contacts.
int	dc_add_contact_to_chat (dc_context_t *context, uint32_t chat_id, uint32_t contact_id)
	Add a member to a group.
uint32_t	dc_add_device_msg (dc_context_t *context, const char *label, dc_msg_t *msg)
	Add a message to the device-chat.
void	dc_block_chat (dc_context_t *context, uint32_t chat_id)
	Block a chat.
void	dc_block_contact (dc_context_t *context, uint32_t contact_id, int block)
	Block or unblock a contact.
dc_lot_t *	dc_chatlist_get_summary2 (dc_context_t *context, uint32_t chat_id, uint32_t msg_id)
	Create a chatlist summary item when the chatlist object is already unref()'d.
dc_lot_t *	dc_check_qr (dc_context_t *context, const char *qr)
	Check a scanned QR code.
void	dc_configure (dc_context_t *context)
	Configure a context.
int	dc_context_is_open (dc_context_t *context)
	Returns 1 if database is open.
dc_context_t *	dc_context_new (const char *os_name, const char *dbfile, const char *blobdir)
	Create a new context object and try to open it without passphrase.
dc_context_t *	dc_context_new_closed (const char *dbfile)
	Create a new context object.
int	dc_context_open (dc_context_t *context, const char *passphrase)
	Opens the database with the given passphrase.
void	dc_context_unref (dc_context_t *context)
	Free a context object.
int	dc_continue_key_transfer (dc_context_t *context, uint32_t msg_id, const char *setup_code)
	Continue the Autocrypt Key Transfer on another device.
uint32_t	dc_create_broadcast_list (dc_context_t *context)
	Create a new broadcast list.
uint32_t	dc_create_chat_by_contact_id (dc_context_t *context, uint32_t contact_id)
	Create a normal chat with a single user.
uint32_t	dc_create_contact (dc_context_t *context, const char *name, const char *addr)
	Add a single contact as a result of an explicit user action.
uint32_t	dc_create_group_chat (dc_context_t *context, int protect, const char *name)
	Create a new group chat.
void	dc_delete_all_locations (dc_context_t *context)
	Delete all locations on the current device.
void	dc_delete_chat (dc_context_t *context, uint32_t chat_id)
	Delete a chat.
int	dc_delete_contact (dc_context_t *context, uint32_t contact_id)
	Delete a contact so that it disappears from the corresponding lists.
void	dc_delete_msgs (dc_context_t *context, const uint32_t *msg_ids, int msg_cnt)
	Delete messages.
void	dc_download_full_msg (dc_context_t *context, int msg_id)
	Asks the core to start downloading a message fully.
int	dc_estimate_deletion_cnt (dc_context_t *context, int from_server, int64_t seconds)
	Estimate the number of messages that will be deleted by the dc_set_config()-options delete_device_after or delete_server_after.
void	dc_forward_msgs (dc_context_t *context, const uint32_t *msg_ids, int msg_cnt, uint32_t chat_id)
	Forward messages to another chat.
char *	dc_get_blobdir (const dc_context_t *context)
	Get the blob directory.
int	dc_get_blocked_cnt (dc_context_t *context)
	Get the number of blocked contacts.
dc_array_t *	dc_get_blocked_contacts (dc_context_t *context)
	Get blocked contacts.
dc_chat_t *	dc_get_chat (dc_context_t *context, uint32_t chat_id)
	Get a chat object by a chat ID.
dc_array_t *	dc_get_chat_contacts (dc_context_t *context, uint32_t chat_id)
	Get the contact IDs belonging to a chat.
char *	dc_get_chat_encrinfo (dc_context_t *context, uint32_t chat_id)
	Get encryption info for a chat.
uint32_t	dc_get_chat_ephemeral_timer (dc_context_t *context, uint32_t chat_id)
	Get the chat's ephemeral message timer.
uint32_t	dc_get_chat_id_by_contact_id (dc_context_t *context, uint32_t contact_id)
	Check, if there is a normal chat with a given contact.
dc_array_t *	dc_get_chat_media (dc_context_t *context, uint32_t chat_id, int msg_type, int msg_type2, int msg_type3)
	Returns all message IDs of the given types in a given chat or any chat.
dc_array_t *	dc_get_chat_msgs (dc_context_t *context, uint32_t chat_id, uint32_t flags, uint32_t marker1before)
	Get all message IDs belonging to a chat.
dc_chatlist_t *	dc_get_chatlist (dc_context_t *context, int flags, const char *query_str, uint32_t query_id)
	Get a list of chats.
char *	dc_get_config (dc_context_t *context, const char *key)
	Get a configuration option.
int	dc_get_connectivity (dc_context_t *context)
	Get the current connectivity, i.e.
char *	dc_get_connectivity_html (dc_context_t *context)
	Get an overview of the current connectivity, and possibly more statistics.
dc_contact_t *	dc_get_contact (dc_context_t *context, uint32_t contact_id)
	Get a single contact object.
char *	dc_get_contact_encrinfo (dc_context_t *context, uint32_t contact_id)
	Get encryption info for a contact.
dc_array_t *	dc_get_contacts (dc_context_t *context, uint32_t flags, const char *query)
	Returns known and unblocked contacts.
dc_msg_t *	dc_get_draft (dc_context_t *context, uint32_t chat_id)
	Get draft for a chat, if any.
dc_event_emitter_t *	dc_get_event_emitter (dc_context_t *context)
	Create the event emitter that is used to receive events.
int	dc_get_fresh_msg_cnt (dc_context_t *context, uint32_t chat_id)
	Get the number of fresh messages in a chat.
dc_array_t *	dc_get_fresh_msgs (dc_context_t *context)
	Returns the message IDs of all fresh messages of any chat.
uint32_t	dc_get_id (dc_context_t *context)
	Get the ID of a context object.
char *	dc_get_info (const dc_context_t *context)
	Get information about the context.
char *	dc_get_last_error (dc_context_t *context)
	Get last error string.
dc_array_t *	dc_get_locations (dc_context_t *context, uint32_t chat_id, uint32_t contact_id, int64_t timestamp_begin, int64_t timestamp_end)
	Get shared locations from the database.
char *	dc_get_mime_headers (dc_context_t *context, uint32_t msg_id)
	Get the raw mime-headers of the given message.
dc_msg_t *	dc_get_msg (dc_context_t *context, uint32_t msg_id)
	Get a single message object of the type dc_msg_t.
int	dc_get_msg_cnt (dc_context_t *context, uint32_t chat_id)
	Get the total number of messages in a chat.
char *	dc_get_msg_html (dc_context_t *context, uint32_t msg_id)
	Get uncut message, if available.
char *	dc_get_msg_info (dc_context_t *context, uint32_t msg_id)
	Get an informational text for a single message.
dc_reactions_t *	dc_get_msg_reactions (dc_context_t *context, int msg_id)
	Get a structure with reactions to the message.
uint32_t	dc_get_next_media (dc_context_t *context, uint32_t msg_id, int dir, int msg_type, int msg_type2, int msg_type3)
	Search next/previous message based on a given message and a list of types.
char *	dc_get_oauth2_url (dc_context_t *context, const char *addr, const char *redirect_uri)
	Get URL that can be used to initiate an OAuth2 authorization.
char *	dc_get_securejoin_qr (dc_context_t *context, uint32_t chat_id)
	Get QR code text that will offer an Setup-Contact or Verified-Group invitation.
char *	dc_get_securejoin_qr_svg (dc_context_t *context, uint32_t chat_id)
	Get QR code image from the QR code text generated by dc_get_securejoin_qr().
char *	dc_get_webxdc_status_updates (dc_context_t *context, uint32_t msg_id, uint32_t serial)
	Get webxdc status updates.
void	dc_imex (dc_context_t *context, int what, const char *param1, const char *param2)
	Import/export things.
char *	dc_imex_has_backup (dc_context_t *context, const char *dir)
	Check if there is a backup file.
char *	dc_initiate_key_transfer (dc_context_t *context)
	Initiate Autocrypt Setup Transfer.
int	dc_is_configured (const dc_context_t *context)
	Check if the context is already configured.
int	dc_is_contact_in_chat (dc_context_t *context, uint32_t chat_id, uint32_t contact_id)
	Check if a given contact ID is a member of a group chat.
int	dc_is_sending_locations_to_chat (dc_context_t *context, uint32_t chat_id)
	Check if location streaming is enabled.
uint32_t	dc_join_securejoin (dc_context_t *context, const char *qr)
	Continue a Setup-Contact or Verified-Group-Invite protocol started on another device with dc_get_securejoin_qr().
uint32_t	dc_lookup_contact_id_by_addr (dc_context_t *context, const char *addr)
	Check if an e-mail address belongs to a known and unblocked contact.
void	dc_marknoticed_chat (dc_context_t *context, uint32_t chat_id)
	Mark all messages in a chat as noticed.
void	dc_markseen_msgs (dc_context_t *context, const uint32_t *msg_ids, int msg_cnt)
	Mark messages as presented to the user.
int	dc_may_be_valid_addr (const char *addr)
	Rough check if a string may be a valid e-mail address.
void	dc_maybe_network (dc_context_t *context)
	This function should be called when there is a hint that the network is available again, e.g.
int	dc_preconfigure_keypair (dc_context_t *context, const char *addr, const char *public_data, const char *secret_data)
	Save a keypair as the default keys for the user.
uint32_t	dc_prepare_msg (dc_context_t *context, uint32_t chat_id, dc_msg_t *msg)
	Prepare a message for sending.
int	dc_receive_backup (dc_context_t *context, const char *qr)
	Gets a backup offered by a dc_backup_provider_t object on another device.
int	dc_remove_contact_from_chat (dc_context_t *context, uint32_t chat_id, uint32_t contact_id)
	Remove a member from a group.
int	dc_resend_msgs (dc_context_t *context, const uint32_t *msg_ids, int msg_cnt)
	Resend messages and make information available for newly added chat members.
dc_array_t *	dc_search_msgs (dc_context_t *context, uint32_t chat_id, const char *query)
	Search messages containing the given query string.
void	dc_send_locations_to_chat (dc_context_t *context, uint32_t chat_id, int seconds)
	Enable or disable location streaming for a chat.
uint32_t	dc_send_msg (dc_context_t *context, uint32_t chat_id, dc_msg_t *msg)
	Send a message defined by a dc_msg_t object to a chat.
uint32_t	dc_send_msg_sync (dc_context_t *context, uint32_t chat_id, dc_msg_t *msg)
	Send a message defined by a dc_msg_t object to a chat, synchronously.
uint32_t	dc_send_reaction (dc_context_t *context, uint32_t msg_id, char *reaction)
	Send a reaction to message.
uint32_t	dc_send_text_msg (dc_context_t *context, uint32_t chat_id, const char *text_to_send)
	Send a simple text message a given chat.
uint32_t	dc_send_videochat_invitation (dc_context_t *context, uint32_t chat_id)
	Send invitation to a videochat.
int	dc_send_webxdc_status_update (dc_context_t *context, uint32_t msg_id, const char *json, const char *descr)
	A webxdc instance sends a status update to its other members.
int	dc_set_chat_ephemeral_timer (dc_context_t *context, uint32_t chat_id, uint32_t timer)
	Set the chat's ephemeral message timer.
int	dc_set_chat_mute_duration (dc_context_t *context, uint32_t chat_id, int64_t duration)
	Set mute duration of a chat.
int	dc_set_chat_name (dc_context_t *context, uint32_t chat_id, const char *name)
	Set group name.
int	dc_set_chat_profile_image (dc_context_t *context, uint32_t chat_id, const char *image)
	Set group profile image.
int	dc_set_chat_protection (dc_context_t *context, uint32_t chat_id, int protect)
	Enable or disable protection against active attacks.
void	dc_set_chat_visibility (dc_context_t *context, uint32_t chat_id, int visibility)
	Set chat visibility to pinned, archived or normal.
int	dc_set_config (dc_context_t *context, const char *key, const char *value)
	Configure the context.
int	dc_set_config_from_qr (dc_context_t *context, const char *qr)
	Set configuration values from a QR code.
void	dc_set_draft (dc_context_t *context, uint32_t chat_id, dc_msg_t *msg)
	Save a draft for a chat in the database.
int	dc_set_location (dc_context_t *context, double latitude, double longitude, double accuracy)
	Set current location.
int	dc_set_stock_translation (dc_context_t *context, uint32_t stock_id, const char *stock_msg)
	Set stock string translation.
void	dc_start_io (dc_context_t *context)
	Start job and IMAP/SMTP tasks.
void	dc_stop_io (dc_context_t *context)
	Stop job, IMAP, SMTP and other tasks and return when they are finished.
void	dc_stop_ongoing_process (dc_context_t *context)
	Signal an ongoing process to stop.
void	dc_str_unref (char *str)
	Release a string returned by another deltachat-core function.
int	dc_was_device_msg_ever_added (dc_context_t *context, const char *label)
	Check if a device-message with a given label was ever added.

Detailed Description

An object representing a single account.

Each account is linked to an IMAP/SMTP account and uses a separate SQLite database for offline functionality and for account related settings.

Member Function Documentation

dc_accept_chat()

void dc_accept_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Accept a contact request chat.

Use it to accept "contact request" chats as indicated by dc_chat_is_contact_request().

If the dc_set_config()-option bot is set, all chats are accepted automatically and calling this function has no effect.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to accept.

dc_add_address_book()

int dc_add_address_book	(	dc_context_t *	context,
		const char *	addr_book
	)

Add a number of contacts.

Typically used to add the whole address book from the OS. As names here are typically not well formatted, we call normalize() for each name given.

No e-mail address is added twice. Trying to add e-mail addresses that are already in the contact list, results in updating the name unless the name was changed manually by the user. If any e-mail address or any name is really updated, the event DC_EVENT_CONTACTS_CHANGED is sent.

To add a single contact entered by the user, you should prefer dc_create_contact(), however, for adding a bunch of addresses, this function is much faster.

Parameters

context	The context object.
addr_book	A multi-line string in the format Name one\nAddress one\nName two\nAddress two. If an e-mail address already exists, the name is updated unless it was edited manually by dc_create_contact() before.

Returns

The number of modified or added contacts.

dc_add_contact_to_chat()

int dc_add_contact_to_chat	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	contact_id
	)

Add a member to a group.

If the group is already promoted (any message was sent to the group), all group members are informed by a special status message that is sent automatically by this function.

If the group has group protection enabled, only verified contacts can be added to the group.

Sends out DC_EVENT_CHAT_MODIFIED and DC_EVENT_MSGS_CHANGED if a status message was sent.

Parameters

context	The context object.
chat_id	The chat ID to add the contact to. Must be a group chat.
contact_id	The contact ID to add to the chat.

Returns

1=member added to group, 0=error

dc_add_device_msg()

uint32_t dc_add_device_msg	(	dc_context_t *	context,
		const char *	label,
		dc_msg_t *	msg
	)

Add a message to the device-chat.

Device-messages usually contain update information and some hints that are added during the program runs, multi-device etc. The device-message may be defined by a label; if a message with the same label was added or skipped before, the message is not added again, even if the message was deleted in between. If needed, the device-chat is created before.

Sends the event DC_EVENT_MSGS_CHANGED on success. To check, if a given chat is a device-chat, see dc_chat_is_device_talk()

Parameters

context	The context object.
label	A unique name for the message to add. The label is typically not displayed to the user and must be created from the characters A-Z, a-z, 0-9, _ or -. If you pass NULL here, the message is added unconditionally.
msg	The message to be added to the device-chat. The message appears to the user as an incoming message. If you pass NULL here, only the given label will be added and block adding messages with that label in the future.

Returns

The ID of the just added message, if the message was already added or no message to add is given, 0 is returned.

Example:

dc_msg_t* welcome_msg = dc_msg_new(DC_MSG_TEXT);
dc_msg_set_text(welcome_msg, "great that you give this app a try!");
 
dc_msg_t* changelog_msg = dc_msg_new(DC_MSG_TEXT);
dc_msg_set_text(changelog_msg, "we have added 3 new emojis :)");
 
if (dc_add_device_msg(context, "welcome", welcome_msg)) {
    // do not add the changelog on a new installations -
    // not now and not when this code is executed again
    dc_add_device_msg(context, "update-123", NULL);
} else {
    // welcome message was not added now, this is an older installation,
    // add a changelog
    dc_add_device_msg(context, "update-123", changelog_msg);
}
 
dc_msg_unref(changelog_msg);
dc_msg_unref(welome_msg);

dc_block_chat()

void dc_block_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Block a chat.

Blocking 1:1 chats blocks the corresponding contact. Blocking mailing lists creates a pseudo-contact in the list of blocked contacts, so blocked mailing lists can be discovered and unblocked the same way as the contacts. Blocking group chats deletes the chat without blocking any contacts, so it may pop up again later.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to block.

dc_block_contact()

void dc_block_contact	(	dc_context_t *	context,
		uint32_t	contact_id,
		int	block
	)

Block or unblock a contact.

May result in a DC_EVENT_CONTACTS_CHANGED event.

Parameters

context	The context object.
contact_id	The ID of the contact to block or unblock.
block	1=block contact, 0=unblock contact

dc_chatlist_get_summary2()

dc_lot_t * dc_chatlist_get_summary2	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	msg_id
	)

Create a chatlist summary item when the chatlist object is already unref()'d.

This function is similar to dc_chatlist_get_summary(), however, it takes the chat ID and the message ID as returned by dc_chatlist_get_chat_id() and dc_chatlist_get_msg_id() as arguments. The chatlist object itself is not needed directly.

This maybe useful if you convert the complete object into a different representation as done e.g. in the node-bindings. If you have access to the chatlist object in some way, using this function is not recommended, use dc_chatlist_get_summary() in this case instead.

Parameters

context	The context object.
chat_id	The chat ID to get a summary for.
msg_id	The message ID to get a summary for.

Returns

The summary as an dc_lot_t object, see dc_chatlist_get_summary() for details. Must be freed using dc_lot_unref(). NULL is never returned.

dc_check_qr()

dc_lot_t * dc_check_qr	(	dc_context_t *	context,
		const char *	qr
	)

Check a scanned QR code.

The function takes the raw text scanned and checks what can be done with it.

The UI is supposed to show the result to the user. In case there are further actions possible, the UI has to ask the user before doing further steps.

The QR code state is returned in dc_lot_t::state as:

• DC_QR_ASK_VERIFYCONTACT with dc_lot_t::id=Contact ID: ask whether to verify the contact; if so, start the protocol with dc_join_securejoin().
• DC_QR_ASK_VERIFYGROUP with dc_lot_t::text1=Group name: ask whether to join the group; if so, start the protocol with dc_join_securejoin().
• DC_QR_FPR_OK with dc_lot_t::id=Contact ID: contact fingerprint verified, ask the user if they want to start chatting; if so, call dc_create_chat_by_contact_id().
• DC_QR_FPR_MISMATCH with dc_lot_t::id=Contact ID: scanned fingerprint does not match last seen fingerprint.
• DC_QR_FPR_WITHOUT_ADDR with dc_lot_t::text1=Formatted fingerprint the scanned QR code contains a fingerprint but no e-mail address; suggest the user to establish an encrypted connection first.
• DC_QR_ACCOUNT dc_lot_t::text1=domain: ask the user if they want to create an account on the given domain, if so, call dc_set_config_from_qr() and then dc_configure().
• DC_QR_BACKUP: ask the user if they want to set up a new device. If so, pass the qr-code to dc_receive_backup().
• DC_QR_WEBRTC_INSTANCE with dc_lot_t::text1=domain: ask the user if they want to use the given service for video chats; if so, call dc_set_config_from_qr().
• DC_QR_ADDR with dc_lot_t::id=Contact ID: e-mail address scanned, optionally, a draft message could be set in dc_lot_t::text1 in which case dc_lot_t::text1_meaning will be DC_TEXT1_DRAFT; ask the user if they want to start chatting; if so, call dc_create_chat_by_contact_id().
• DC_QR_TEXT with dc_lot_t::text1=Text: Text scanned, ask the user e.g. if they want copy to clipboard.
• DC_QR_URL with dc_lot_t::text1=URL: URL scanned, ask the user e.g. if they want to open a browser or copy to clipboard.
• DC_QR_ERROR with dc_lot_t::text1=Error string: show the error to the user.
• DC_QR_WITHDRAW_VERIFYCONTACT: ask the user if they want to withdraw the their own qr-code; if so, call dc_set_config_from_qr().
• DC_QR_WITHDRAW_VERIFYGROUP with text1=groupname: ask the user if they want to withdraw the group-invite code; if so, call dc_set_config_from_qr().
• DC_QR_REVIVE_VERIFYCONTACT: ask the user if they want to revive their withdrawn qr-code; if so, call dc_set_config_from_qr().
• DC_QR_REVIVE_VERIFYGROUP with text1=groupname: ask the user if they want to revive the withdrawn group-invite code; if so, call dc_set_config_from_qr().
• DC_QR_LOGIN with dc_lot_t::text1=email_address: ask the user if they want to login with the email_address, if so, call dc_set_config_from_qr() and then dc_configure().

Parameters

context	The context object.
qr	The text of the scanned QR code.

Returns

The parsed QR code as an dc_lot_t object. The returned object must be freed using dc_lot_unref() after usage.

dc_configure()

void dc_configure

(

dc_context_t *

context

)

Configure a context.

During configuration IO must not be started, if needed stop IO using dc_accounts_stop_io() or dc_stop_io() first. If the context is already configured, this function will try to change the configuration.

• Before you call this function, you must set at least addr and mail_pw using dc_set_config().
• Use mail_user to use a different user name than addr and send_pw to use a different password for the SMTP server.
  • If no more options are specified, the function uses autoconfigure/autodiscover to get the full configuration from well-known URLs.
  • If more options as mail_server, mail_port, send_server, send_port, send_user or server_flags are specified, autoconfigure/autodiscover is skipped.

While dc_configure() returns immediately, the started configuration-job may take a while.

During configuration, DC_EVENT_CONFIGURE_PROGRESS events are emitted; they indicate a successful configuration as well as errors and may be used to create a progress bar.

Additional calls to dc_configure() while a config-job is running are ignored. To interrupt a configuration prematurely, use dc_stop_ongoing_process(); this is not needed if DC_EVENT_CONFIGURE_PROGRESS reports success.

If DC_EVENT_CONFIGURE_PROGRESS reports failure, the core continues to use the last working configuration and parameters as addr, mail_pw etc. are set to that.

Parameters

context

The context object.

There is no need to call dc_configure() on every program start, the configuration result is saved in the database and you can use the connection directly:

if (!dc_is_configured(context)) {
    dc_configure(context);
    // wait for progress events
}

dc_context_is_open()

int dc_context_is_open

(

dc_context_t *

context

)

Returns 1 if database is open.

Parameters

context

The context object.

Returns

1 if database is open, 0 if database is closed.

dc_context_new()

dc_context_t * dc_context_new	(	const char *	os_name,
		const char *	dbfile,
		const char *	blobdir
	)

Create a new context object and try to open it without passphrase.

If database is encrypted, the result is the same as using dc_context_new_closed() and the database should be opened with dc_context_open() before using.

Parameters

os_name	Deprecated, pass NULL or empty string here.
dbfile	The file to use to store the database, something like ~/file won't work, use absolute paths.
blobdir	Deprecated, pass NULL or an empty string here.

Returns

A context object with some public members. The object must be passed to the other context functions and must be freed using dc_context_unref() after usage.

dc_context_new_closed()

dc_context_t * dc_context_new_closed

(

const char *

dbfile

)

Create a new context object.

After creation it is usually opened with dc_context_open() and started with dc_start_io() so it is connected and mails are fetched.

Parameters

dbfile

The file to use to store the database, something like ~/file won't work, use absolute paths.

Returns

A context object with some public members. The object must be passed to the other context functions and must be freed using dc_context_unref() after usage.

If you want to use multiple context objects at the same time, this can be managed using dc_accounts_t.

dc_context_open()

int dc_context_open	(	dc_context_t *	context,
		const char *	passphrase
	)

Opens the database with the given passphrase.

This can only be used on closed context, such as created by dc_context_new_closed(). If the database is new, this operation sets the database passphrase. For existing databases the passphrase should be the one used to encrypt the database the first time.

Parameters

context	The context object.
passphrase	The passphrase to use with the database. Pass NULL or empty string to use no passphrase and no encryption.

Returns

1 if the database is opened with this passphrase, 0 if the passphrase is incorrect and on error.

dc_context_unref()

void dc_context_unref

(

dc_context_t *

context

)

Free a context object.

You have to call this function also for accounts returned by dc_accounts_get_account() or dc_accounts_get_selected_account().

Parameters

context

The context object as created by dc_context_new(), dc_accounts_get_account() or dc_accounts_get_selected_account(). If NULL is given, nothing is done.

dc_continue_key_transfer()

int dc_continue_key_transfer	(	dc_context_t *	context,
		uint32_t	msg_id,
		const char *	setup_code
	)

Continue the Autocrypt Key Transfer on another device.

If you have started the key transfer on another device using dc_initiate_key_transfer() and you've detected a setup message with dc_msg_is_setupmessage(), you should prompt the user for the setup code and call this function then.

You can use dc_msg_get_setupcodebegin() to give the user a hint about the code (useful if the user has created several messages and should not enter the wrong code).

Parameters

context	The context object.
msg_id	The ID of the setup message to decrypt.
setup_code	The setup code entered by the user. This is the same setup code as returned from dc_initiate_key_transfer() on the other device. There is no need to format the string correctly, the function will remove all spaces and other characters and insert the - characters at the correct places.

Returns

1=key successfully decrypted and imported; both devices will use the same key now; 0=key transfer failed e.g. due to a bad setup code.

dc_create_broadcast_list()

uint32_t dc_create_broadcast_list

(

dc_context_t *

context

)

Create a new broadcast list.

Broadcast lists are similar to groups on the sending device, however, recipients get the messages in normal one-to-one chats and will not be aware of other members.

Replies to broadcasts go only to the sender and not to all broadcast recipients. Moreover, replies will not appear in the broadcast list but in the one-to-one chat with the person answering.

The name and the image of the broadcast list is set automatically and is visible to the sender only. Not asking for these data allows more focused creation and we bypass the question who will get which data. Also, many users will have at most one broadcast list so, a generic name and image is sufficient at the first place.

Later on, however, the name can be changed using dc_set_chat_name(). The image cannot be changed to have a unique, recognizable icon in the chat lists. All in all, this is also what other messengers are doing here.

Parameters

context

The context object.

Returns

The chat ID of the new broadcast list, 0 on errors.

dc_create_chat_by_contact_id()

uint32_t dc_create_chat_by_contact_id	(	dc_context_t *	context,
		uint32_t	contact_id
	)

Create a normal chat with a single user.

To create group chats, see dc_create_group_chat().

If a chat already exists, this ID is returned, otherwise a new chat is created; to get the chat messages, use dc_get_chat_msgs().

Parameters

context	The context object as returned from dc_context_new().
contact_id	The contact ID to create the chat for. If there is already a chat with this contact, the already existing ID is returned.

Returns

The created or reused chat ID on success. 0 on errors.

dc_create_contact()

uint32_t dc_create_contact	(	dc_context_t *	context,
		const char *	name,
		const char *	addr
	)

Add a single contact as a result of an explicit user action.

We assume, the contact name, if any, is entered by the user and is used "as is" therefore, normalize() is not called for the name. If the contact is blocked, it is unblocked.

To add a number of contacts, see dc_add_address_book() which is much faster for adding a bunch of addresses.

May result in a DC_EVENT_CONTACTS_CHANGED event.

Parameters

context	The context object.
name	The name of the contact to add. If you do not know the name belonging to the address, you can give NULL here.
addr	The e-mail address of the contact to add. If the e-mail address already exists, the name is updated and the origin is increased to "manually created".

Returns

The contact ID of the created or reused contact.

dc_create_group_chat()

uint32_t dc_create_group_chat	(	dc_context_t *	context,
		int	protect,
		const char *	name
	)

Create a new group chat.

After creation, the group has one member with the ID DC_CONTACT_ID_SELF and is in unpromoted state. This means, you can add or remove members, change the name, the group image and so on without messages being sent to all group members.

This changes as soon as the first message is sent to the group members and the group becomes promoted. After that, all changes are synced with all group members by sending status message.

To check, if a chat is still unpromoted, you dc_chat_is_unpromoted(). This may be useful if you want to show some help for just created groups.

Parameters

context	The context object.
protect	If set to 1 the function creates group with protection initially enabled. Only verified members are allowed in these groups and end-to-end-encryption is always enabled.
name	The name of the group chat to create. The name may be changed later using dc_set_chat_name(). To find out the name of a group later, see dc_chat_get_name()

Returns

The chat ID of the new group chat, 0 on errors.

dc_delete_all_locations()

void dc_delete_all_locations

(

dc_context_t *

context

)

Delete all locations on the current device.

Locations already sent cannot be deleted.

Typically results in the event DC_EVENT_LOCATION_CHANGED with contact_id set to 0.

Parameters

context

The context object.

dc_delete_chat()

void dc_delete_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Delete a chat.

Messages are deleted from the device and the chat database entry is deleted. After that, the event DC_EVENT_MSGS_CHANGED is posted.

Things that are not done implicitly:

• Messages are not deleted from the server.
• The chat or the contact is not blocked, so new messages from the user/the group may appear and the user may create the chat again.
• Groups are not left - this would be unexpected as (1) deleting a normal chat also does not prevent new mails from arriving, (2) leaving a group requires sending a message to all group members - especially for groups not used for a longer time, this is really unexpected when deletion results in contacting all members again, (3) only leaving groups is also a valid usecase.

To leave a chat explicitly, use dc_remove_contact_from_chat() with chat_id=DC_CONTACT_ID_SELF)

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to delete.

dc_delete_contact()

int dc_delete_contact	(	dc_context_t *	context,
		uint32_t	contact_id
	)

Delete a contact so that it disappears from the corresponding lists.

Depending on whether there are ongoing chats, deletion is done by physical deletion or hiding. The contact is deleted from the local device.

May result in a DC_EVENT_CONTACTS_CHANGED event.

Parameters

context	The context object.
contact_id	The ID of the contact to delete.

Returns

1=success, 0=error

dc_delete_msgs()

void dc_delete_msgs	(	dc_context_t *	context,
		const uint32_t *	msg_ids,
		int	msg_cnt
	)

Delete messages.

The messages are deleted on the current device and on the IMAP server.

Parameters

context	The context object.
msg_ids	An array of uint32_t containing all message IDs that should be deleted.
msg_cnt	The number of messages IDs in the msg_ids array.

dc_download_full_msg()

void dc_download_full_msg	(	dc_context_t *	context,
		int	msg_id
	)

Asks the core to start downloading a message fully.

This function is typically called when the user hits the "Download" button that is shown by the UI in case dc_msg_get_download_state() returns DC_DOWNLOAD_AVAILABLE or DC_DOWNLOAD_FAILURE.

On success, the view type of the message may change or the message may be replaced completely by one or more messages with other message IDs. That may happen e.g. in cases where the message was encrypted and the type could not be determined without fully downloading. Downloaded content can be accessed as usual after download, e.g. using dc_msg_get_file().

To reflect these changes a DC_EVENT_MSGS_CHANGED event will be emitted.

Parameters

context	The context object.
msg_id	The message ID to download the content for.

dc_estimate_deletion_cnt()

int dc_estimate_deletion_cnt	(	dc_context_t *	context,
		int	from_server,
		int64_t	seconds
	)

Estimate the number of messages that will be deleted by the dc_set_config()-options delete_device_after or delete_server_after.

This is typically used to show the estimated impact to the user before actually enabling deletion of old messages.

Parameters

context	The context object as returned from dc_context_new().
from_server	1=Estimate deletion count for server, 0=Estimate deletion count for device
seconds	Count messages older than the given number of seconds.

Returns

Number of messages that are older than the given number of seconds. This includes e-mails downloaded due to the show_emails option. Messages in the "saved messages" folder are not counted as they will not be deleted automatically.

dc_forward_msgs()

void dc_forward_msgs	(	dc_context_t *	context,
		const uint32_t *	msg_ids,
		int	msg_cnt,
		uint32_t	chat_id
	)

Forward messages to another chat.

All types of messages can be forwarded, however, they will be flagged as such (dc_msg_is_forwarded() is set).

Original sender, info-state and webxdc updates are not forwarded on purpose.

Parameters

context	The context object.
msg_ids	An array of uint32_t containing all message IDs that should be forwarded.
msg_cnt	The number of messages IDs in the msg_ids array.
chat_id	The destination chat ID.

dc_get_blobdir()

char * dc_get_blobdir

(

const dc_context_t *

context

)

Get the blob directory.

Parameters

context

The context object.

Returns

The blob directory associated with the context object, empty string if unset or on errors. NULL is never returned. The returned string must be released using dc_str_unref().

dc_get_blocked_cnt()

int dc_get_blocked_cnt

(

dc_context_t *

context

)

Get the number of blocked contacts.

Deprecated:

Deprecated 2021-02-22, use dc_array_get_cnt() on dc_get_blocked_contacts() instead.

Parameters

context

The context object.

Returns

The number of blocked contacts.

dc_get_blocked_contacts()

dc_array_t * dc_get_blocked_contacts

(

dc_context_t *

context

)

Get blocked contacts.

Parameters

context

The context object.

Returns

An array containing all blocked contact IDs. Must be dc_array_unref()'d after usage.

dc_get_chat()

dc_chat_t * dc_get_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get a chat object by a chat ID.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to get the chat object for.

Returns

A chat object of the type dc_chat_t, must be freed using dc_chat_unref() when done. On errors, NULL is returned.

dc_get_chat_contacts()

dc_array_t * dc_get_chat_contacts	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get the contact IDs belonging to a chat.

• for normal chats, the function always returns exactly one contact, DC_CONTACT_ID_SELF is returned only for SELF-chats.
• for group chats all members are returned, DC_CONTACT_ID_SELF is returned explicitly as it may happen that oneself gets removed from a still existing group
• for broadcasts, all recipients are returned, DC_CONTACT_ID_SELF is not included
• for mailing lists, the behavior is not documented currently, we will decide on that later. for now, the UI should not show the list for mailing lists. (we do not know all members and there is not always a global mailing list address, so we could return only SELF or the known members; this is not decided yet)

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to get the belonging contact IDs for.

Returns

An array of contact IDs belonging to the chat; must be freed using dc_array_unref() when done.

dc_get_chat_encrinfo()

char * dc_get_chat_encrinfo	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get encryption info for a chat.

Get a multi-line encryption info, containing encryption preferences of all members. Can be used to find out why messages sent to group are not encrypted.

Parameters

context	The context object.
chat_id	The ID of the chat to get the encryption info for.

Returns

Multi-line text, must be released using dc_str_unref() after usage.

dc_get_chat_ephemeral_timer()

uint32_t dc_get_chat_ephemeral_timer	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get the chat's ephemeral message timer.

The ephemeral message timer is set by dc_set_chat_ephemeral_timer() on this or any other device participating in the chat.

Parameters

context	The context object.
chat_id	The chat ID.

Returns

ephemeral timer value in seconds, 0 if the timer is disabled or if there is an error

dc_get_chat_id_by_contact_id()

uint32_t dc_get_chat_id_by_contact_id	(	dc_context_t *	context,
		uint32_t	contact_id
	)

Check, if there is a normal chat with a given contact.

To get the chat messages, use dc_get_chat_msgs().

Parameters

context	The context object as returned from dc_context_new().
contact_id	The contact ID to check.

Returns

If there is a normal chat with the given contact_id, this chat_id is returned. If there is no normal chat with the contact_id, the function returns 0.

dc_get_chat_media()

dc_array_t * dc_get_chat_media	(	dc_context_t *	context,
		uint32_t	chat_id,
		int	msg_type,
		int	msg_type2,
		int	msg_type3
	)

Returns all message IDs of the given types in a given chat or any chat.

Typically used to show a gallery. The result must be dc_array_unref()'d

The list is already sorted and starts with the oldest message. Clients should not try to re-sort the list as this would be an expensive action and would result in inconsistencies between clients.

Parameters

context	The context object as returned from dc_context_new().
chat_id	>0: get messages with media from this chat ID. 0: get messages with media from any chat of the currently used account.
msg_type	Specify a message type to query here, one of the DC_MSG constants.
msg_type2	Alternative message type to search for. 0 to skip.
msg_type3	Alternative message type to search for. 0 to skip.

Returns

An array with messages from the given chat ID that have the wanted message types.

dc_get_chat_msgs()

dc_array_t * dc_get_chat_msgs	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	flags,
		uint32_t	marker1before
	)

Get all message IDs belonging to a chat.

The list is already sorted and starts with the oldest message. Clients should not try to re-sort the list as this would be an expensive action and would result in inconsistencies between clients.

Optionally, some special markers added to the ID array may help to implement virtual lists.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID of which the messages IDs should be queried.
flags	If set to DC_GCM_ADDDAYMARKER, the marker DC_MSG_ID_DAYMARKER will be added before each day (regarding the local timezone). Set this to 0 if you do not want this behaviour. To get the concrete time of the marker, use dc_array_get_timestamp(). If set to DC_GCM_INFO_ONLY, only system messages will be returned, can be combined with DC_GCM_ADDDAYMARKER.
marker1before	Deprecated, set this to 0.

Returns

Array of message IDs, must be dc_array_unref()'d when no longer used.

dc_get_chatlist()

dc_chatlist_t * dc_get_chatlist	(	dc_context_t *	context,
		int	flags,
		const char *	query_str,
		uint32_t	query_id
	)

Get a list of chats.

The list can be filtered by query parameters.

The list is already sorted and starts with the most recent chat in use. The sorting takes care of invalid sending dates, drafts and chats without messages. Clients should not try to re-sort the list as this would be an expensive action and would result in inconsistencies between clients.

To get information about each entry, use e.g. dc_chatlist_get_summary().

By default, the function adds some special entries to the list. These special entries can be identified by the ID returned by dc_chatlist_get_chat_id():

• DC_CHAT_ID_ARCHIVED_LINK (6) - this special chat is present if the user has archived any chat using dc_set_chat_visibility(). The UI should show a link as "Show archived chats", if the user clicks this item, the UI should show a list of all archived chats that can be created by this function hen using the DC_GCL_ARCHIVED_ONLY flag.
• DC_CHAT_ID_ALLDONE_HINT (7) - this special chat is present if DC_GCL_ADD_ALLDONE_HINT is added to listflags and if there are only archived chats.

Parameters

context	The context object as returned by dc_context_new().
flags	A combination of flags: if the flag DC_GCL_ARCHIVED_ONLY is set, only archived chats are returned. if DC_GCL_ARCHIVED_ONLY is not set, only unarchived chats are returned and the pseudo-chat DC_CHAT_ID_ARCHIVED_LINK is added if there are any archived chats the flag DC_GCL_FOR_FORWARDING sorts "Saved messages" to the top of the chatlist and hides the "Device chat" and contact requests. typically used on forwarding, may be combined with DC_GCL_NO_SPECIALS to also hide the archive link. if the flag DC_GCL_NO_SPECIALS is set, archive link is not added to the list (may be used e.g. for selecting chats on forwarding, the flag is not needed when DC_GCL_ARCHIVED_ONLY is already set) if the flag DC_GCL_ADD_ALLDONE_HINT is set, DC_CHAT_ID_ALLDONE_HINT is added as needed.
query_str	An optional query for filtering the list. Only chats matching this query are returned. Give NULL for no filtering.
query_id	An optional contact ID for filtering the list. Only chats including this contact ID are returned. Give 0 for no filtering.

Returns

A chatlist as an dc_chatlist_t object. On errors, NULL is returned. Must be freed using dc_chatlist_unref() when no longer used.

See also: dc_get_chat_msgs() to get the messages of a single chat.

dc_get_config()

char * dc_get_config	(	dc_context_t *	context,
		const char *	key
	)

Get a configuration option.

The configuration option is set by dc_set_config() or by the library itself.

Beside the options shown at dc_set_config(), this function can be used to query some global system values:

• sys.version = get the version string e.g. as 1.2.3 or as 1.2.3special4.
• sys.msgsize_max_recommended = maximal recommended attachment size in bytes. All possible overheads are already subtracted and this value can be used e.g. for direct comparison with the size of a file the user wants to attach. If an attachment is larger than this value, an error (no warning as it should be shown to the user) is logged but the attachment is sent anyway.
• sys.config_keys = get a space-separated list of all config-keys available. The config-keys are the keys that can be passed to the parameter key of this function.
• quota_exceeding = 0: quota is unknown or in normal range; >=80: quota is about to exceed, the value is the concrete percentage, a device message is added when that happens, however, that value may still be interesting for bots.

Parameters

context	The context object. For querying system values, this can be NULL.
key	The key to query.

Returns

Returns current value of "key", if "key" is unset, the default value is returned. The returned value must be released using dc_str_unref(), NULL is never returned. If there is an error an empty string will be returned.

dc_get_connectivity()

int dc_get_connectivity

(

dc_context_t *

context

)

Get the current connectivity, i.e.

whether the device is connected to the IMAP server. One of:

• DC_CONNECTIVITY_NOT_CONNECTED (1000-1999): Show e.g. the string "Not connected" or a red dot
• DC_CONNECTIVITY_CONNECTING (2000-2999): Show e.g. the string "Connecting…" or a yellow dot
• DC_CONNECTIVITY_WORKING (3000-3999): Show e.g. the string "Getting new messages" or a spinning wheel
• DC_CONNECTIVITY_CONNECTED (>=4000): Show e.g. the string "Connected" or a green dot

We don't use exact values but ranges here so that we can split up states into multiple states in the future.

Meant as a rough overview that can be shown e.g. in the title of the main screen.

If the connectivity changes, a DC_EVENT_CONNECTIVITY_CHANGED will be emitted.

Parameters

context

The context object.

Returns

The current connectivity.

dc_get_connectivity_html()

char * dc_get_connectivity_html

(

dc_context_t *

context

)

Get an overview of the current connectivity, and possibly more statistics.

Meant to give the user more insight about the current status than the basic connectivity info returned by dc_get_connectivity(); show this e.g., if the user taps on said basic connectivity info.

If this page changes, a DC_EVENT_CONNECTIVITY_CHANGED will be emitted.

This comes as an HTML from the core so that we can easily improve it and the improvement instantly reaches all UIs.

Parameters

context

The context object.

Returns

An HTML page with some info about the current connectivity and status.

dc_get_contact()

dc_contact_t * dc_get_contact	(	dc_context_t *	context,
		uint32_t	contact_id
	)

Get a single contact object.

For a list, see e.g. dc_get_contacts().

For contact DC_CONTACT_ID_SELF (1), the function returns sth. like "Me" in the selected language and the e-mail address defined by dc_set_config().

Parameters

context	The context object.
contact_id	The ID of the contact to get the object for.

Returns

The contact object, must be freed using dc_contact_unref() when no longer used. NULL on errors.

dc_get_contact_encrinfo()

char * dc_get_contact_encrinfo	(	dc_context_t *	context,
		uint32_t	contact_id
	)

Get encryption info for a contact.

Get a multi-line encryption info, containing your fingerprint and the fingerprint of the contact, used e.g. to compare the fingerprints for a simple out-of-band verification.

Parameters

context	The context object.
contact_id	The ID of the contact to get the encryption info for.

Returns

Multi-line text, must be released using dc_str_unref() after usage.

dc_get_contacts()

dc_array_t * dc_get_contacts	(	dc_context_t *	context,
		uint32_t	flags,
		const char *	query
	)

Returns known and unblocked contacts.

To get information about a single contact, see dc_get_contact().

Parameters

context	The context object.
flags	A combination of flags: if the flag DC_GCL_ADD_SELF is set, SELF is added to the list unless filtered by other parameters if the flag DC_GCL_VERIFIED_ONLY is set, only verified contacts are returned. if DC_GCL_VERIFIED_ONLY is not set, verified and unverified contacts are returned.
query	A string to filter the list. Typically used to implement an incremental search. NULL for no filtering.

Returns

An array containing all contact IDs. Must be dc_array_unref()'d after usage.

dc_get_draft()

dc_msg_t * dc_get_draft	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get draft for a chat, if any.

See dc_set_draft() for more details about drafts.

Parameters

context	The context object.
chat_id	The chat ID to get the draft for.

Returns

Message object. Can be passed directly to dc_send_msg(). Must be freed using dc_msg_unref() after usage. If there is no draft, NULL is returned.

dc_get_event_emitter()

dc_event_emitter_t * dc_get_event_emitter

(

dc_context_t *

context

)

Create the event emitter that is used to receive events.

The library will emit various DC_EVENT events, such as "new message", "message read" etc. To get these events, you have to create an event emitter using this function and call dc_get_next_event() on the emitter.

Parameters

context

The context object as created by dc_context_new().

Returns

Returns the event emitter, NULL on errors. Must be freed using dc_event_emitter_unref() after usage.

Note: Use only one event emitter per context. Having more than one event emitter running at the same time on the same context will result in events being randomly delivered to one of the emitters.

dc_get_fresh_msg_cnt()

int dc_get_fresh_msg_cnt	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get the number of fresh messages in a chat.

Typically used to implement a badge with a number in the chatlist.

As muted archived chats are not unarchived automatically, a similar information is needed for the archive link as well: here, the number of archived chats containing fresh messages is returned.

If the specified chat is muted or the archive link, the UI should show the badge counter "less obtrusive", e.g. using "gray" instead of "red" color.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to count the messages for.

Returns

Number of fresh messages in the given chat. 0 for errors or if there are no fresh messages.

dc_get_fresh_msgs()

dc_array_t * dc_get_fresh_msgs

(

dc_context_t *

context

)

Returns the message IDs of all fresh messages of any chat.

Typically used for implementing notification summaries or badge counters e.g. on the app icon. The list is already sorted and starts with the most recent fresh message.

Messages belonging to muted chats or to the contact requests are not returned; these messages should not be notified and also badge counters should not include these messages.

To get the number of fresh messages for a single chat, muted or not, use dc_get_fresh_msg_cnt().

Parameters

context

The context object as returned from dc_context_new().

Returns

An array of message IDs, must be dc_array_unref()'d when no longer used. On errors, the list is empty. NULL is never returned.

dc_get_id()

uint32_t dc_get_id

(

dc_context_t *

context

)

Get the ID of a context object.

Each context has an ID assigned. If the context was created through the dc_accounts_t account manager, the ID is unique, no other context handled by the account manager will have the same ID. If the context was created by dc_context_new(), a random ID is assigned.

Parameters

context

The context object as created e.g. by dc_accounts_get_account() or dc_context_new().

Returns

The context-id.

dc_get_info()

char * dc_get_info

(

const dc_context_t *

context

)

Get information about the context.

The information is returned by a multi-line string and contains information about the current configuration.

If the context is not open or configured only a subset of the information will be available. There is no guarantee about which information will be included when however.

Parameters

context

The context object.

Returns

The string which must be released using dc_str_unref() after usage. Never returns NULL.

dc_get_last_error()

char * dc_get_last_error

(

dc_context_t *

context

)

Get last error string.

This is the same error string as logged via DC_EVENT_ERROR, however, using this function avoids race conditions if the failing function is called in another thread than dc_get_next_event().

Parameters

context

The context object.

Returns

Last error or an empty string if there is no last error. NULL is never returned. The returned value must be released using dc_str_unref() after usage.

dc_get_locations()

dc_array_t * dc_get_locations	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	contact_id,
		int64_t	timestamp_begin,
		int64_t	timestamp_end
	)

Get shared locations from the database.

The locations can be filtered by the chat ID, the contact ID, and by a timespan.

The number of returned locations can be retrieved using dc_array_get_cnt(). To get information for each location, use dc_array_get_latitude(), dc_array_get_longitude(), dc_array_get_accuracy(), dc_array_get_timestamp(), dc_array_get_contact_id() and dc_array_get_msg_id(). The latter returns 0 if there is no message bound to the location.

Note that only if dc_array_is_independent() returns 0, the location is the current or a past position of the user. If dc_array_is_independent() returns 1, the location is any location on earth that is marked by the user.

Parameters

context	The context object.
chat_id	The chat ID to get location information for. 0 to get locations independently of the chat.
contact_id	The contact ID to get location information for. If also a chat ID is given, this should be a member of the given chat. 0 to get locations independently of the contact.
timestamp_begin	The start of timespan to return. Must be given in number of seconds since 00:00 hours, Jan 1, 1970 UTC. 0 for "start from the beginning".
timestamp_end	The end of timespan to return. Must be given in number of seconds since 00:00 hours, Jan 1, 1970 UTC. 0 for "all up to now".

Returns

An array of locations, NULL is never returned. The array is sorted descending; the first entry in the array is the location with the newest timestamp. Note that this is only related to the recent position of the user if dc_array_is_independent() returns 0. The returned array must be freed using dc_array_unref().

Examples:

// get locations from the last hour for a global map
dc_array_t* loc = dc_get_locations(context, 0, 0, time(NULL)-60*60, 0);
for (int i=0; i<dc_array_get_cnt(); i++) {
    double lat = dc_array_get_latitude(loc, i);
    ...
}
dc_array_unref(loc);
 
// get locations from a contact for a global map
dc_array_t* loc = dc_get_locations(context, 0, contact_id, 0, 0);
...
 
// get all locations known for a given chat
dc_array_t* loc = dc_get_locations(context, chat_id, 0, 0, 0);
...
 
// get locations from a single contact for a given chat
dc_array_t* loc = dc_get_locations(context, chat_id, contact_id, 0, 0);
...

dc_get_mime_headers()

char * dc_get_mime_headers	(	dc_context_t *	context,
		uint32_t	msg_id
	)

Get the raw mime-headers of the given message.

Raw headers are saved for incoming messages only if dc_set_config(context, "save_mime_headers", "1") was called before.

Parameters

context	The context object.
msg_id	The message ID, must be the ID of an incoming message.

Returns

Raw headers as a multi-line string, must be released using dc_str_unref() after usage. Returns NULL if there are no headers saved for the given message, e.g. because of save_mime_headers is not set or the message is not incoming.

dc_get_msg()

dc_msg_t * dc_get_msg	(	dc_context_t *	context,
		uint32_t	msg_id
	)

Get a single message object of the type dc_msg_t.

For a list of messages in a chat, see dc_get_chat_msgs() For a list or chats, see dc_get_chatlist()

Parameters

context	The context object.
msg_id	The message ID for which the message object should be created.

Returns

A dc_msg_t message object. On errors, NULL is returned. When done, the object must be freed using dc_msg_unref().

dc_get_msg_cnt()

int dc_get_msg_cnt	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get the total number of messages in a chat.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to count the messages for.

Returns

Number of total messages in the given chat. 0 for errors or empty chats.

dc_get_msg_html()

char * dc_get_msg_html	(	dc_context_t *	context,
		uint32_t	msg_id
	)

Get uncut message, if available.

Delta Chat tries to break the message in simple parts as plain text or images that are retrieved using dc_msg_get_viewtype(), dc_msg_get_text(), dc_msg_get_file() and so on. This works totally fine for Delta Chat to Delta Chat communication, however, when the counterpart uses another E-Mail-client, this has limits:

• even if we do some good job on removing quotes, sometimes one needs to see them
• HTML-only messages might lose information on conversion to text, esp. when there are lots of embedded images
• even if there is some plain text part for a HTML-message, this is often poor and not nicely usable due to long links

In these cases, dc_msg_has_html() returns 1 and you can ask dc_get_msg_html() for some HTML-code that shows the uncut text (which is close to the original) For simplicity, the function always returns HTML-code, this removes the need for the UI to deal with different formatting options of PLAIN-parts.

As the title of the full-message-view, you can use the subject (see dc_msg_get_subject()).

Note: The returned HTML-code may contain scripts, external images that may be misused as hidden read-receipts and so on. Taking care of these parts while maintaining compatibility with the then generated HTML-code is not easily doable, if at all. E.g. taking care of tags and attributes is not sufficient, we would have to deal with linked content (e.g. script, css), text (e.g. script-blocks) and values (e.g. javascript-protocol) as well; on this level, we have to deal with encodings, browser peculiarities and so on - and would still risk to oversee something and to break things.

To avoid starting this cat-and-mouse game, and to close this issue in a sustainable way, it is up to the UI to display the HTML-code in an appropriate sandbox environment - that may e.g. be an external browser or a WebView with scripting disabled.

Parameters

context	The context object.
msg_id	The message ID for which the uncut text should be loaded.

Returns

Uncut text as HTML. In case of errors, NULL is returned. The result must be released using dc_str_unref().

dc_get_msg_info()

char * dc_get_msg_info	(	dc_context_t *	context,
		uint32_t	msg_id
	)

Get an informational text for a single message.

The text is multiline and may contain e.g. the raw text of the message.

The max. text returned is typically longer (about 100000 characters) than the max. text returned by dc_msg_get_text() (about 30000 characters).

Parameters

context	The context object.
msg_id	The message ID for which information should be generated.

Returns

Text string, must be released using dc_str_unref() after usage

dc_get_msg_reactions()

dc_reactions_t * dc_get_msg_reactions	(	dc_context_t *	context,
		int	msg_id
	)

Get a structure with reactions to the message.

Parameters

context	The context object.
msg_id	The message ID to get reactions for.

Returns

A structure with all reactions to the message.

dc_get_next_media()

uint32_t dc_get_next_media	(	dc_context_t *	context,
		uint32_t	msg_id,
		int	dir,
		int	msg_type,
		int	msg_type2,
		int	msg_type3
	)

Search next/previous message based on a given message and a list of types.

Typically used to implement the "next" and "previous" buttons in a gallery or in a media player.

Parameters

context	The context object as returned from dc_context_new().
msg_id	The ID of the current message from which the next or previous message should be searched.
dir	1=get the next message, -1=get the previous one.
msg_type	The message type to search for. If 0, the message type from curr_msg_id is used.
msg_type2	Alternative message type to search for. 0 to skip.
msg_type3	Alternative message type to search for. 0 to skip.

Returns

Returns the message ID that should be played next. The returned message is in the same chat as the given one and has one of the given types. Typically, this result is passed again to dc_get_next_media() later on the next swipe. If there is not next/previous message, the function returns 0.

dc_get_oauth2_url()

char * dc_get_oauth2_url	(	dc_context_t *	context,
		const char *	addr,
		const char *	redirect_uri
	)

Get URL that can be used to initiate an OAuth2 authorization.

If an OAuth2 authorization is possible for a given e-mail address, this function returns the URL that should be opened in a browser.

If the user authorizes access, the given redirect_uri is called by the provider. It's up to the UI to handle this call.

The provider will attach some parameters to the URL, most important the parameter code that should be set as the mail_pw. With server_flags set to DC_LP_AUTH_OAUTH2, dc_configure() can be called as usual afterwards.

Parameters

context	The context object.
addr	E-mail address the user has entered. In case the user selects a different e-mail address during authorization, this is corrected in dc_configure()
redirect_uri	URL that will get code that is used as mail_pw then. Not all URLs are allowed here, however, the following should work: chat.delta:/PATH, http://localhost:PORT/PATH, https://localhost:PORT/PATH, urn:ietf:wg:oauth:2.0:oob (the latter just displays the code the user can copy+paste then)

Returns

URL that can be opened in the browser to start OAuth2. Returned strings must be released using dc_str_unref(). If OAuth2 is not possible for the given e-mail address, NULL is returned.

dc_get_securejoin_qr()

char * dc_get_securejoin_qr	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get QR code text that will offer an Setup-Contact or Verified-Group invitation.

The QR code is compatible to the OPENPGP4FPR format so that a basic fingerprint comparison also works e.g. with OpenKeychain.

The scanning device will pass the scanned content to dc_check_qr() then; if dc_check_qr() returns DC_QR_ASK_VERIFYCONTACT or DC_QR_ASK_VERIFYGROUP an out-of-band-verification can be joined using dc_join_securejoin()

Parameters

context	The context object.
chat_id	If set to a group-chat-id, the Verified-Group-Invite protocol is offered in the QR code; works for protected groups as well as for normal groups. If set to 0, the Setup-Contact protocol is offered in the QR code. See https://countermitm.readthedocs.io/en/latest/new.html for details about both protocols.

Returns

The text that should go to the QR code, On errors, an empty QR code is returned, NULL is never returned. The returned string must be released using dc_str_unref() after usage.

dc_get_securejoin_qr_svg()

char * dc_get_securejoin_qr_svg	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Get QR code image from the QR code text generated by dc_get_securejoin_qr().

See dc_get_securejoin_qr() for details about the contained QR code.

Parameters

context	The context object.
chat_id	group-chat-id for secure-join or 0 for setup-contact, see dc_get_securejoin_qr() for details.

Returns

SVG-Image with the QR code. On errors, an empty string is returned. The returned string must be released using dc_str_unref() after usage.

dc_get_webxdc_status_updates()

char * dc_get_webxdc_status_updates	(	dc_context_t *	context,
		uint32_t	msg_id,
		uint32_t	serial
	)

Get webxdc status updates.

The status updates may be sent by yourself or by other members using dc_send_webxdc_status_update(). In both cases, you will be informed by DC_EVENT_WEBXDC_STATUS_UPDATE whenever there is a new update.

In JS land, that would be mapped to something as:

window.webxdc.setUpdateListener((update) => {
   if (update.payload.action === "move") {
      print(update.payload.src)
      print(update.payload.dest)
   }
});

Parameters

context	The context object.
msg_id	The ID of the message with the webxdc instance.
serial	The last known serial. Pass 0 if there are no known serials to receive all updates.

Returns

JSON-array containing the requested updates. Each update comes with the following properties:

• update.payload: equals the payload given to dc_send_webxdc_status_update()
• update.serial: the serial number of this update. Serials are larger 0 and newer serials have higher numbers.
• update.max_serial: the maximum serial currently known. If max_serial equals serial this update is the last update (until new network messages arrive).
• update.info: optional, short, informational message.
• update.summary: optional, short text, shown beside app icon. If there are no updates, an empty JSON-array is returned.

dc_imex()

void dc_imex	(	dc_context_t *	context,
		int	what,
		const char *	param1,
		const char *	param2
	)

Import/export things.

What to do is defined by the what parameter which may be one of the following:

• DC_IMEX_EXPORT_BACKUP (11) - Export a backup to the directory given as param1 encrypted with the passphrase given as param2. If param2 is NULL or empty string, the backup is not encrypted. The backup contains all contacts, chats, images and other data and device independent settings. The backup does not contain device dependent settings as ringtones or LED notification settings. The name of the backup is typically delta-chat-<day>.tar, if more than one backup is create on a day, the format is delta-chat-<day>-<number>.tar
• DC_IMEX_IMPORT_BACKUP (12) - param1 is the file (not: directory) to import. param2 is the passphrase. The file is normally created by DC_IMEX_EXPORT_BACKUP and detected by dc_imex_has_backup(). Importing a backup is only possible as long as the context is not configured or used in another way.
• DC_IMEX_EXPORT_SELF_KEYS (1) - Export all private keys and all public keys of the user to the directory given as param1. The default key is written to the files public-key-default.asc and private-key-default.asc, if there are more keys, they are written to files as public-key-<id>.asc and private-key-<id>.asc
• DC_IMEX_IMPORT_SELF_KEYS (2) - Import private keys found in the directory given as param1. The last imported key is made the default keys unless its name contains the string legacy. Public keys are not imported.

While dc_imex() returns immediately, the started job may take a while, you can stop it using dc_stop_ongoing_process(). During execution of the job, some events are sent out:

• A number of DC_EVENT_IMEX_PROGRESS events are sent and may be used to create a progress bar or stuff like that. Moreover, you will be informed when the imex-job is done.
• For each file written on export, the function sends DC_EVENT_IMEX_FILE_WRITTEN

Only one import-/export-progress can run at the same time. To cancel an import-/export-progress, use dc_stop_ongoing_process().

Parameters

context	The context.
what	One of the DC_IMEX_* constants.
param1	Meaning depends on the DC_IMEX_* constants. If this parameter is a directory, it should not end with a slash (otherwise you will get double slashes when receiving DC_EVENT_IMEX_FILE_WRITTEN). Set to NULL if not used.
param2	Meaning depends on the DC_IMEX_* constants. Set to NULL if not used.

dc_imex_has_backup()

char * dc_imex_has_backup	(	dc_context_t *	context,
		const char *	dir
	)

Check if there is a backup file.

May only be used on fresh installations (e.g. dc_is_configured() returns 0).

Example:

char dir[] = "/dir/to/search/backups/in";
 
void ask_user_for_credentials()
{
    // - ask the user for e-mail and password
    // - save them using dc_set_config()
}
 
int ask_user_whether_to_import()
{
    // - inform the user that we've found a backup
    // - ask if he want to import it
    // - return 1 to import, 0 to skip
    return 1;
}
 
if (!dc_is_configured(context))
{
    char* file = NULL;
    if ((file=dc_imex_has_backup(context, dir))!=NULL && ask_user_whether_to_import())
    {
        dc_imex(context, DC_IMEX_IMPORT_BACKUP, file, NULL);
        // connect
    }
    else
    {
        do {
            ask_user_for_credentials();
        }
        while (!configure_succeeded())
    }
    dc_str_unref(file);
}

Parameters

context	The context object.
dir	The directory to search backups in.

Returns

String with the backup file, typically given to dc_imex(), returned strings must be released using dc_str_unref(). The function returns NULL if no backup was found.

dc_initiate_key_transfer()

char * dc_initiate_key_transfer

(

dc_context_t *

context

)

Initiate Autocrypt Setup Transfer.

Before starting the setup transfer with this function, the user should be asked:

"An 'Autocrypt Setup Message' securely shares your end-to-end setup with other Autocrypt-compliant apps.
The setup will be encrypted by a setup code which is displayed here and must be typed on the other device.

After that, this function should be called to send the Autocrypt Setup Message. The function creates the setup message and adds it to outgoing message queue. The message is sent asynchronously.

The required setup code is returned in the following format:

1234-1234-1234-1234-1234-1234-1234-1234-1234

The setup code should be shown to the user then:

"Your key has been sent to yourself. Switch to the other device and
open the setup message. You should be prompted for a setup code. Type
the following digits into the prompt:
 
1234 - 1234 - 1234 -
1234 - 1234 - 1234 -
1234 - 1234 - 1234
 
Once you're done, your other device will be ready to use Autocrypt."

On the other device you will call dc_continue_key_transfer() then for setup messages identified by dc_msg_is_setupmessage().

For more details about the Autocrypt setup process, please refer to https://autocrypt.org/en/latest/level1.html#autocrypt-setup-message

Parameters

context

The context object.

Returns

The setup code. Must be released using dc_str_unref() after usage. On errors, e.g. if the message could not be sent, NULL is returned.

dc_is_configured()

int dc_is_configured

(

const dc_context_t *

context

)

Check if the context is already configured.

Typically, for unconfigured accounts, the user is prompted to enter some settings and dc_configure() is called in a thread then.

A once successfully configured context cannot become unconfigured again; if a subsequent call to dc_configure() fails, the prior configuration is used.

However, of course, also a configuration may stop working, as e.g. the password was changed on the server. To check that use e.g. dc_get_connectivity().

Parameters

context

The context object.

Returns

1=context is configured and can be used; 0=context is not configured and a configuration by dc_configure() is required.

dc_is_contact_in_chat()

int dc_is_contact_in_chat	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	contact_id
	)

Check if a given contact ID is a member of a group chat.

Parameters

context	The context object.
chat_id	The chat ID to check.
contact_id	The contact ID to check. To check if yourself is member of the chat, pass DC_CONTACT_ID_SELF (1) here.

Returns

1=contact ID is member of chat ID, 0=contact is not in chat

dc_is_sending_locations_to_chat()

int dc_is_sending_locations_to_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Check if location streaming is enabled.

Location stream can be enabled or disabled using dc_send_locations_to_chat(). If you have already a dc_chat_t object, dc_chat_is_sending_locations() may be more handy.

Parameters

context	The context object.
chat_id	>0: Check if location streaming is enabled for the given chat. 0: Check of location streaming is enabled for any chat.

Returns

1: location streaming is enabled for the given chat(s); 0: location streaming is disabled for the given chat(s).

dc_join_securejoin()

uint32_t dc_join_securejoin	(	dc_context_t *	context,
		const char *	qr
	)

Continue a Setup-Contact or Verified-Group-Invite protocol started on another device with dc_get_securejoin_qr().

This function is typically called when dc_check_qr() returns lot.state=DC_QR_ASK_VERIFYCONTACT or lot.state=DC_QR_ASK_VERIFYGROUP.

The function returns immediately and the handshake runs in background, sending and receiving several messages. During the handshake, info messages are added to the chat, showing progress, success or errors.

Subsequent calls of dc_join_securejoin() will abort previous, unfinished handshakes.

See https://countermitm.readthedocs.io/en/latest/new.html for details about both protocols.

Parameters

context	The context object.
qr	The text of the scanned QR code. Typically, the same string as given to dc_check_qr().

Returns

The chat ID of the joined chat, the UI may redirect to the this chat. On errors, 0 is returned, however, most errors will happen during handshake later on. A returned chat ID does not guarantee that the chat is protected or the belonging contact is verified.

dc_lookup_contact_id_by_addr()

uint32_t dc_lookup_contact_id_by_addr	(	dc_context_t *	context,
		const char *	addr
	)

Check if an e-mail address belongs to a known and unblocked contact.

To get a list of all known and unblocked contacts, use dc_get_contacts().

To validate an e-mail address independently of the contact database use dc_may_be_valid_addr().

Parameters

context	The context object.
addr	The e-mail address to check.

Returns

The contact ID of the contact belonging to the e-mail address or 0 if there is no contact that is or was introduced by an accepted contact.

dc_marknoticed_chat()

void dc_marknoticed_chat	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Mark all messages in a chat as noticed.

Noticed messages are no longer fresh and do not count as being unseen but are still waiting for being marked as "seen" using dc_markseen_msgs() (IMAP/MDNs is not done for noticed messages).

Calling this function usually results in the event DC_EVENT_MSGS_NOTICED. See also dc_markseen_msgs().

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID of which all messages should be marked as being noticed.

dc_markseen_msgs()

void dc_markseen_msgs	(	dc_context_t *	context,
		const uint32_t *	msg_ids,
		int	msg_cnt
	)

Mark messages as presented to the user.

Typically, UIs call this function on scrolling through the message list, when the messages are presented at least for a little moment. The concrete action depends on the type of the chat and on the users settings (dc_msgs_presented() may be a better name therefore, but well. :)

• For normal chats, the IMAP state is updated, MDN is sent (if dc_set_config()-options mdns_enabled is set) and the internal state is changed to DC_STATE_IN_SEEN to reflect these actions.
• For contact requests, no IMAP or MDNs is done and the internal state is not changed therefore. See also dc_marknoticed_chat().

Moreover, timer is started for incoming ephemeral messages. This also happens for contact requests chats.

One DC_EVENT_MSGS_NOTICED event is emitted per modified chat.

Parameters

context	The context object.
msg_ids	An array of uint32_t containing all the messages IDs that should be marked as seen.
msg_cnt	The number of message IDs in msg_ids.

dc_may_be_valid_addr()

int dc_may_be_valid_addr

(

const char *

addr

)

Rough check if a string may be a valid e-mail address.

The function checks if the string contains a minimal amount of characters before and after the @ and . characters.

To check if a given address is a contact in the contact database use dc_lookup_contact_id_by_addr().

Parameters

addr	The e-mail address to check.

Returns

1=address may be a valid e-mail address, 0=address won't be a valid e-mail address

dc_maybe_network()

void dc_maybe_network

(

dc_context_t *

context

)

This function should be called when there is a hint that the network is available again, e.g.

as a response to system event reporting network availability. The library will try to send pending messages out immediately.

Moreover, to have a reliable state when the app comes to foreground with network available, it may be reasonable to call the function also at that moment.

It is okay to call the function unconditionally when there is network available, however, calling the function without having network may interfere with the backoff algorithm and will led to let the jobs fail faster, with fewer retries and may avoid messages being sent out.

Finally, if the context was created by the dc_accounts_t account manager, use dc_accounts_maybe_network() instead of this function.

Parameters

context

The context as created by dc_context_new().

dc_preconfigure_keypair()

int dc_preconfigure_keypair	(	dc_context_t *	context,
		const char *	addr,
		const char *	public_data,
		const char *	secret_data
	)

Save a keypair as the default keys for the user.

This API is only for testing purposes and should not be used as part of a normal application, use the import-export APIs instead.

This saves a public/private keypair as the default keypair in the context. It allows avoiding having to generate a secret key for unittests which need one.

Parameters

context	The context as created by dc_context_new().
addr	The e-mail address of the user. This must match the configured_addr setting of the context as well as the UID of the key.
public_data	ASCII armored public key.
secret_data	ASCII armored secret key.

Returns

1 on success, 0 on failure.

dc_prepare_msg()

uint32_t dc_prepare_msg	(	dc_context_t *	context,
		uint32_t	chat_id,
		dc_msg_t *	msg
	)

Prepare a message for sending.

Call this function if the file to be sent is still in creation. Once you're done with creating the file, call dc_send_msg() as usual and the message will really be sent.

This is useful as the user can already send the next messages while e.g. the recoding of a video is not yet finished. Or the user can even forward the message with the file being still in creation to other groups.

Files being sent with the increation-method must be placed in the blob directory, see dc_get_blobdir(). If the increation-method is not used - which is probably the normal case - dc_send_msg() copies the file to the blob directory if it is not yet there. To distinguish the two cases, msg->state must be set properly. The easiest way to ensure this is to re-use the same object for both calls.

Example:

char* blobdir = dc_get_blobdir(context);
char* file_to_send = mprintf("%s/%s", blobdir, "send.mp4")
 
dc_msg_t* msg = dc_msg_new(context, DC_MSG_VIDEO);
dc_msg_set_file(msg, file_to_send, NULL);
dc_prepare_msg(context, chat_id, msg);
 
// ... create the file ...
 
dc_send_msg(context, chat_id, msg);
 
dc_msg_unref(msg);
free(file_to_send);
dc_str_unref(file_to_send);

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID to send the message to.
msg	The message object to send to the chat defined by the chat ID. On success, msg_id and state of the object are set up, The function does not take ownership of the object, so you have to free it using dc_msg_unref() as usual.

Returns

The ID of the message that is being prepared.

dc_receive_backup()

int dc_receive_backup	(	dc_context_t *	context,
		const char *	qr
	)

Gets a backup offered by a dc_backup_provider_t object on another device.

This function is called on a device that scanned the QR code offered by dc_backup_sender_qr() or dc_backup_sender_qr_svg(). Typically this is a different device than that which provides the backup.

This call will block while the backup is being transferred and only complete on success or failure. Use dc_stop_ongoing_process() to abort it early.

During execution of the job DC_EVENT_IMEX_PROGRESS is sent out to indicate state and progress. The process is finished when the event emits either 0 or 1000, 0 means it failed and 1000 means it succeeded. These events are for showing progress and informational only, success and failure is also shown in the return code of this function.

Parameters

context	The context.
qr	The qr code text, dc_check_qr() must have returned DC_QR_BACKUP on this text.

Returns

0=failure, 1=success.

dc_remove_contact_from_chat()

int dc_remove_contact_from_chat	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	contact_id
	)

Remove a member from a group.

If the group is already promoted (any message was sent to the group), all group members are informed by a special status message that is sent automatically by this function.

Sends out DC_EVENT_CHAT_MODIFIED and DC_EVENT_MSGS_CHANGED if a status message was sent.

Parameters

context	The context object.
chat_id	The chat ID to remove the contact from. Must be a group chat.
contact_id	The contact ID to remove from the chat.

Returns

1=member removed from group, 0=error

dc_resend_msgs()

int dc_resend_msgs	(	dc_context_t *	context,
		const uint32_t *	msg_ids,
		int	msg_cnt
	)

Resend messages and make information available for newly added chat members.

Resending sends out the original message, however, recipients and webxdc-status may differ. Clients that already have the original message can still ignore the resent message as they have tracked the state by dedicated updates.

Some messages cannot be resent, eg. info-messages, drafts, already pending messages or messages that are not sent by SELF. In this case, the return value indicates an error and the error string from dc_get_last_error() should be shown to the user.

Parameters

context	The context object.
msg_ids	An array of uint32_t containing all message IDs that should be resend. All messages must belong to the same chat.
msg_cnt	The number of messages IDs in the msg_ids array.

Returns

1=all messages are queued for resending, 0=error

dc_search_msgs()

dc_array_t * dc_search_msgs	(	dc_context_t *	context,
		uint32_t	chat_id,
		const char *	query
	)

Search messages containing the given query string.

Searching can be done globally (chat_id=0) or in a specified chat only (chat_id set).

Global chat results are typically displayed using dc_msg_get_summary(), chat search results may just hilite the corresponding messages and present a prev/next button.

For global search, result is limited to 1000 messages, this allows incremental search done fast. So, when getting exactly 1000 results, the result may be truncated; the UIs may display sth. as "1000+ messages found" in this case. Chat search (if a chat_id is set) is not limited.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to search messages in. Set this to 0 for a global search.
query	The query to search for.

Returns

An array of message IDs. Must be freed using dc_array_unref() when no longer needed. If nothing can be found, the function returns NULL.

dc_send_locations_to_chat()

void dc_send_locations_to_chat	(	dc_context_t *	context,
		uint32_t	chat_id,
		int	seconds
	)

Enable or disable location streaming for a chat.

Locations are sent to all members of the chat for the given number of seconds; after that, location streaming is automatically disabled for the chat. The current location streaming state of a chat can be checked using dc_is_sending_locations_to_chat().

The locations that should be sent to the chat can be set using dc_set_location().

Parameters

context	The context object.
chat_id	The chat ID to enable location streaming for.
seconds	>0: enable location streaming for the given number of seconds; 0: disable location streaming.

dc_send_msg()

uint32_t dc_send_msg	(	dc_context_t *	context,
		uint32_t	chat_id,
		dc_msg_t *	msg
	)

Send a message defined by a dc_msg_t object to a chat.

Sends the event DC_EVENT_MSGS_CHANGED on success. However, this does not imply, the message really reached the recipient - sending may be delayed e.g. due to network problems. However, from your view, you're done with the message. Sooner or later it will find its way.

Example:

dc_msg_t* msg = dc_msg_new(context, DC_MSG_IMAGE);
 
dc_msg_set_file(msg, "/file/to/send.jpg", NULL);
dc_send_msg(context, chat_id, msg);
 
dc_msg_unref(msg);

If you send images with the DC_MSG_IMAGE type, they will be recoded to a reasonable size before sending, if possible (cmp the dc_set_config()-option media_quality). If that fails, is not possible, or the image is already small enough, the image is sent as original. If you want images to be always sent as the original file, use the DC_MSG_FILE type.

Videos and other file types are currently not recoded by the library, with dc_prepare_msg(), however, you can do that from the UI.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID to send the message to. If dc_prepare_msg() was called before, this parameter can be 0.
msg	The message object to send to the chat defined by the chat ID. On success, msg_id of the object is set up, The function does not take ownership of the object, so you have to free it using dc_msg_unref() as usual.

Returns

The ID of the message that is about to be sent. 0 in case of errors.

dc_send_msg_sync()

uint32_t dc_send_msg_sync	(	dc_context_t *	context,
		uint32_t	chat_id,
		dc_msg_t *	msg
	)

Send a message defined by a dc_msg_t object to a chat, synchronously.

This bypasses the IO scheduler and creates its own SMTP connection. Which means this is useful when the scheduler is not running.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID to send the message to. If dc_prepare_msg() was called before, this parameter can be 0.
msg	The message object to send to the chat defined by the chat ID. On success, msg_id of the object is set up, The function does not take ownership of the object, so you have to free it using dc_msg_unref() as usual.

Returns

The ID of the message that is about to be sent. 0 in case of errors.

dc_send_reaction()

uint32_t dc_send_reaction	(	dc_context_t *	context,
		uint32_t	msg_id,
		char *	reaction
	)

Send a reaction to message.

Reaction is a string of emojis separated by spaces. Reaction to a single message can be sent multiple times. The last reaction received overrides all previously received reactions. It is possible to remove all reactions by sending an empty string.

Parameters

context	The context object.
msg_id	ID of the message you react to.
reaction	A string consisting of emojis separated by spaces.

Returns

The ID of the message sent out or 0 for errors.

dc_send_text_msg()

uint32_t dc_send_text_msg	(	dc_context_t *	context,
		uint32_t	chat_id,
		const char *	text_to_send
	)

Send a simple text message a given chat.

Sends the event DC_EVENT_MSGS_CHANGED on success. However, this does not imply, the message really reached the recipient - sending may be delayed e.g. due to network problems. However, from your view, you're done with the message. Sooner or later it will find its way.

See also dc_send_msg().

Parameters

context	The context object as returned from dc_context_new().
chat_id	The chat ID to send the text message to.
text_to_send	Text to send to the chat defined by the chat ID. Passing an empty text here causes an empty text to be sent, it's up to the caller to handle this if undesired. Passing NULL as the text causes the function to return 0.

Returns

The ID of the message that is about being sent.

dc_send_videochat_invitation()

uint32_t dc_send_videochat_invitation	(	dc_context_t *	context,
		uint32_t	chat_id
	)

Send invitation to a videochat.

This function reads the webrtc_instance config value, may check that the server is working in some way and creates a unique room for this chat, if needed doing a TOKEN roundtrip for that.

After that, the function sends out a message that contains information to join the room:

• To allow non-delta-clients to join the chat, the message contains a text-area with some descriptive text and a URL that can be opened in a supported browser to join the videochat.
• delta-clients can get all information needed from the message object, using e.g. dc_msg_get_videochat_url() and check dc_msg_get_viewtype() for DC_MSG_VIDEOCHAT_INVITATION.

dc_send_videochat_invitation() is blocking and may take a while, so the UIs will typically call the function from within a thread. Moreover, UIs will typically enter the room directly without an additional click on the message, for this purpose, the function returns the message id directly.

As for other messages sent, this function sends the event DC_EVENT_MSGS_CHANGED on success, the message has a delivery state, and so on. The recipient will get noticed by the call as usual by DC_EVENT_INCOMING_MSG or DC_EVENT_MSGS_CHANGED, However, UIs might some things differently, e.g. play a different sound.

Parameters

context	The context object.
chat_id	The chat to start a videochat for.

Returns

The ID of the message sent out or 0 for errors.

dc_send_webxdc_status_update()

int dc_send_webxdc_status_update	(	dc_context_t *	context,
		uint32_t	msg_id,
		const char *	json,
		const char *	descr
	)

A webxdc instance sends a status update to its other members.

In JS land, that would be mapped to something as:

success = window.webxdc.sendUpdate('{"action":"move","src":"A3","dest":"B4"}', 'move A3 B4');

context and msg_id are not needed in JS as those are unique within a webxdc instance. See dc_get_webxdc_status_updates() for the receiving counterpart.

If the webxdc instance is a draft, the update is not sent immediately. Instead, the updates are collected and sent out in a batch when the instance is actually sent. This allows preparing webxdc instances, e.g. defining a poll with predefined answers.

Other members will be informed by DC_EVENT_WEBXDC_STATUS_UPDATE that there is a new update. You will also get the DC_EVENT_WEBXDC_STATUS_UPDATE yourself and the update you sent will also be included in dc_get_webxdc_status_updates().

Parameters

context	The context object.
msg_id	The ID of the message with the webxdc instance.
json	program-readable data, the actual payload
descr	The user-visible description of JSON data, in case of a chess game, e.g. the move.

Returns

1=success, 0=error

dc_set_chat_ephemeral_timer()

int dc_set_chat_ephemeral_timer	(	dc_context_t *	context,
		uint32_t	chat_id,
		uint32_t	timer
	)

Set the chat's ephemeral message timer.

This timer is applied to all messages in a chat and starts when the message is read. For outgoing messages, the timer starts once the message is sent, for incoming messages, the timer starts once dc_markseen_msgs() is called.

The setting is synchronized to all clients participating in a chat.

Parameters

context	The context object.
chat_id	The chat ID to set the ephemeral message timer for.
timer	The timer value in seconds or 0 to disable the timer.

Returns

1=success, 0=error

dc_set_chat_mute_duration()

int dc_set_chat_mute_duration	(	dc_context_t *	context,
		uint32_t	chat_id,
		int64_t	duration
	)

Set mute duration of a chat.

The UI can then call dc_chat_is_muted() when receiving a new message to decide whether it should trigger an notification.

Muted chats should not sound or vibrate and should not show a visual notification in the system area. Moreover, muted chats should be excluded from global badge counter (dc_get_fresh_msgs() skips muted chats therefore) and the in-app, per-chat badge counter should use a less obtrusive color.

Sends out DC_EVENT_CHAT_MODIFIED.

Parameters

chat_id	The chat ID to set the mute duration.
duration	The duration (0 for no mute, -1 for forever mute, everything else is is the relative mute duration from now in seconds)
context	The context object.

Returns

1=success, 0=error

dc_set_chat_name()

int dc_set_chat_name	(	dc_context_t *	context,
		uint32_t	chat_id,
		const char *	name
	)

Set group name.

If the group is already promoted (any message was sent to the group), all group members are informed by a special status message that is sent automatically by this function.

Sends out DC_EVENT_CHAT_MODIFIED and DC_EVENT_MSGS_CHANGED if a status message was sent.

Parameters

chat_id	The chat ID to set the name for. Must be a group chat.
name	New name of the group.
context	The context object.

Returns

1=success, 0=error

dc_set_chat_profile_image()

int dc_set_chat_profile_image	(	dc_context_t *	context,
		uint32_t	chat_id,
		const char *	image
	)

Set group profile image.

If the group is already promoted (any message was sent to the group), all group members are informed by a special status message that is sent automatically by this function.

Sends out DC_EVENT_CHAT_MODIFIED and DC_EVENT_MSGS_CHANGED if a status message was sent.

To find out the profile image of a chat, use dc_chat_get_profile_image()

Parameters

context	The context object.
chat_id	The chat ID to set the image for.
image	Full path of the image to use as the group image. The image will immediately be copied to the blobdir; the original image will not be needed anymore. If you pass NULL here, the group image is deleted (for promoted groups, all members are informed about this change anyway).

Returns

1=success, 0=error

dc_set_chat_protection()

int dc_set_chat_protection	(	dc_context_t *	context,
		uint32_t	chat_id,
		int	protect
	)

Enable or disable protection against active attacks.

To enable protection, it is needed that all members are verified; if this condition is met, end-to-end-encryption is always enabled and only the verified keys are used.

Sends out DC_EVENT_CHAT_MODIFIED on changes and DC_EVENT_MSGS_CHANGED if a status message was sent.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to change the protection for.
protect	1=protect chat, 0=unprotect chat

Returns

1=success, 0=error, e.g. some members may be unverified

dc_set_chat_visibility()

void dc_set_chat_visibility	(	dc_context_t *	context,
		uint32_t	chat_id,
		int	visibility
	)

Set chat visibility to pinned, archived or normal.

Calling this function usually results in the event DC_EVENT_MSGS_CHANGED See DC_CHAT_VISIBILITY for detailed information about the visibilities.

Parameters

context	The context object as returned from dc_context_new().
chat_id	The ID of the chat to change the visibility for.
visibility	one of DC_CHAT_VISIBILITY

dc_set_config()

int dc_set_config	(	dc_context_t *	context,
		const char *	key,
		const char *	value
	)

Configure the context.

The configuration is handled by key=value pairs as:

• addr = address to display (always needed)
• mail_server = IMAP-server, guessed if left out
• mail_user = IMAP-username, guessed if left out
• mail_pw = IMAP-password (always needed)
• mail_port = IMAP-port, guessed if left out
• mail_security= IMAP-socket, one of DC_SOCKET, defaults to DC_SOCKET_AUTO
• send_server = SMTP-server, guessed if left out
• send_user = SMTP-user, guessed if left out
• send_pw = SMTP-password, guessed if left out
• send_port = SMTP-port, guessed if left out
• send_security= SMTP-socket, one of DC_SOCKET, defaults to DC_SOCKET_AUTO
• server_flags = IMAP-/SMTP-flags as a combination of DC_LP flags, guessed if left out
• socks5_enabled = SOCKS5 enabled
• socks5_host = SOCKS5 proxy server host
• socks5_port = SOCKS5 proxy server port
• socks5_user = SOCKS5 proxy username
• socks5_password = SOCKS5 proxy password
• imap_certificate_checks = how to check IMAP certificates, one of the DC_CERTCK flags, defaults to DC_CERTCK_AUTO (0)
• smtp_certificate_checks = how to check SMTP certificates, one of the DC_CERTCK flags, defaults to DC_CERTCK_AUTO (0)
• displayname = Own name to use when sending messages. MUAs are allowed to spread this way e.g. using CC, defaults to empty
• selfstatus = Own status to display, e.g. in e-mail footers, defaults to empty
• selfavatar = File containing avatar. Will immediately be copied to the blobdir; the original image will not be needed anymore. NULL to remove the avatar. As for displayname and selfstatus, also the avatar is sent to the recipients. To save traffic, however, the avatar is attached only as needed and also recoded to a reasonable size.
• e2ee_enabled = 0=no end-to-end-encryption, 1=prefer end-to-end-encryption (default)
• mdns_enabled = 0=do not send or request read receipts, 1=send and request read receipts (default)
• bcc_self = 0=do not send a copy of outgoing messages to self (default), 1=send a copy of outgoing messages to self. Sending messages to self is needed for a proper multi-account setup, however, on the other hand, may lead to unwanted notifications in non-delta clients.
• sentbox_watch= 1=watch Sent-folder for changes, 0=do not watch the Sent-folder (default), changes require restarting IO by calling dc_stop_io() and then dc_start_io().
• mvbox_move = 1=detect chat messages, move them to the DeltaChat folder, and watch the DeltaChat folder for updates (default), 0=do not move chat-messages changes require restarting IO by calling dc_stop_io() and then dc_start_io().
• only_fetch_mvbox = 1=Do not fetch messages from folders other than the DeltaChat folder. Messages will still be fetched from the spam folder and sendbox_watch will also still be respected if enabled. 0=watch all folders normally (default) changes require restarting IO by calling dc_stop_io() and then dc_start_io().
• show_emails = DC_SHOW_EMAILS_OFF (0)= show direct replies to chats only (default), DC_SHOW_EMAILS_ACCEPTED_CONTACTS (1)= also show all mails of confirmed contacts, DC_SHOW_EMAILS_ALL (2)= also show mails of unconfirmed contacts.
• key_gen_type = DC_KEY_GEN_DEFAULT (0)= generate recommended key type (default), DC_KEY_GEN_RSA2048 (1)= generate RSA 2048 keypair DC_KEY_GEN_ED25519 (2)= generate Ed25519 keypair
• save_mime_headers = 1=save mime headers and make dc_get_mime_headers() work for subsequent calls, 0=do not save mime headers (default)
• delete_device_after = 0=do not delete messages from device automatically (default), >=1=seconds, after which messages are deleted automatically from the device. Messages in the "saved messages" chat (see dc_chat_is_self_talk()) are skipped. Messages are deleted whether they were seen or not, the UI should clearly point that out. See also dc_estimate_deletion_cnt().
• delete_server_after = 0=do not delete messages from server automatically (default), 1=delete messages directly after receiving from server, mvbox is skipped. >1=seconds, after which messages are deleted automatically from the server, mvbox is used as defined. "Saved messages" are deleted from the server as well as e-mails matching the show_emails settings above, the UI should clearly point that out. See also dc_estimate_deletion_cnt().
• media_quality = DC_MEDIA_QUALITY_BALANCED (0) = good outgoing images/videos/voice quality at reasonable sizes (default) DC_MEDIA_QUALITY_WORSE (1) allow worse images/videos/voice quality to gain smaller sizes, suitable for providers or areas known to have a bad connection. The library uses the media_quality setting to use different defaults for recoding images sent with type DC_MSG_IMAGE. If needed, recoding other file types is up to the UI.
• webrtc_instance = webrtc instance to use for videochats in the form [basicwebrtc:|jitsi:]https://example.com/subdir#roomname=$ROOM if the URL is prefixed by basicwebrtc, the server is assumed to be of the type https://github.com/cracker0dks/basicwebrtc which some UIs have native support for. The type jitsi: may be handled by external apps. If no type is prefixed, the videochat is handled completely in a browser.
• bot = Set to "1" if this is a bot. Prevents adding the "Device messages" and "Saved messages" chats, adds Auto-Submitted header to outgoing messages and accepts contact requests automatically (calling dc_accept_chat() is not needed for bots).
• fetch_existing_msgs = 1=fetch most recent existing messages on configure (default), 0=do not fetch existing messages on configure. In both cases, existing recipients are added to the contact database.
• download_limit = Messages up to this number of bytes are downloaded automatically. For larger messages, only the header is downloaded and a placeholder is shown. These messages can be downloaded fully using dc_download_full_msg() later. The limit is compared against raw message sizes, including headers. The actually used limit may be corrected to not mess up with non-delivery-reports or read-receipts. 0=no limit (default). Changes affect future messages only.
• ui.* = All keys prefixed by ui. can be used by the user-interfaces for system-specific purposes. The prefix should be followed by the system and maybe subsystem, e.g. ui.desktop.foo, ui.desktop.linux.bar, ui.android.foo, ui.dc40.bar, ui.bot.simplebot.baz. These keys go to backups and allow easy per-account settings when using dc_accounts_t, however, are not handled by the core otherwise.

If you want to retrieve a value, use dc_get_config().

Parameters

context	The context object.
key	The option to change, see above.
value	The value to save for "key"

Returns

0=failure, 1=success

dc_set_config_from_qr()

int dc_set_config_from_qr	(	dc_context_t *	context,
		const char *	qr
	)

Set configuration values from a QR code.

Before this function is called, dc_check_qr() should confirm the type of the QR code is DC_QR_ACCOUNT, DC_QR_LOGIN or DC_QR_WEBRTC_INSTANCE.

Internally, the function will call dc_set_config() with the appropriate keys, e.g. addr and mail_pw for DC_QR_ACCOUNT and DC_QR_LOGIN or webrtc_instance for DC_QR_WEBRTC_INSTANCE.

Parameters

context	The context object.
qr	The scanned QR code.

Returns

int (==0 on error, 1 on success)

dc_set_draft()

void dc_set_draft	(	dc_context_t *	context,
		uint32_t	chat_id,
		dc_msg_t *	msg
	)

Save a draft for a chat in the database.

The UI should call this function if the user has prepared a message and exits the compose window without clicking the "send" button before. When the user later opens the same chat again, the UI can load the draft using dc_get_draft() allowing the user to continue editing and sending.

Drafts are considered when sorting messages and are also returned e.g. by dc_chatlist_get_summary().

Each chat can have its own draft but only one draft per chat is possible.

If the draft is modified, an DC_EVENT_MSGS_CHANGED will be sent.

Parameters

context	The context object.
chat_id	The chat ID to save the draft for.
msg	The message to save as a draft. Existing draft will be overwritten. NULL deletes the existing draft, if any, without sending it.

dc_set_location()

int dc_set_location	(	dc_context_t *	context,
		double	latitude,
		double	longitude,
		double	accuracy
	)

Set current location.

The location is sent to all chats where location streaming is enabled using dc_send_locations_to_chat().

Typically results in the event DC_EVENT_LOCATION_CHANGED with contact_id set to DC_CONTACT_ID_SELF.

The UI should call this function on all location changes. The locations set by this function are not sent immediately, instead a message with the last locations is sent out every some minutes or when the user sends out a normal message, the last locations are attached.

Parameters

context	The context object.
latitude	A north-south position of the location. Set to 0.0 if the latitude is not known.
longitude	East-west position of the location. Set to 0.0 if the longitude is not known.
accuracy	Estimated accuracy of the location, radial, in meters. Set to 0.0 if the accuracy is not known.

Returns

1: location streaming is still enabled for at least one chat, this dc_set_location() should be called as soon as the location changes; 0: location streaming is no longer needed, dc_is_sending_locations_to_chat() is false for all chats.

dc_set_stock_translation()

int dc_set_stock_translation	(	dc_context_t *	context,
		uint32_t	stock_id,
		const char *	stock_msg
	)

Set stock string translation.

The function will emit warnings if it returns an error state.

Parameters

context	The context object.
stock_id	The integer ID of the stock message, one of the DC_STR constants.
stock_msg	The message to be used.

Returns

int (==0 on error, 1 on success)

dc_start_io()

void dc_start_io

(

dc_context_t *

context

)

Start job and IMAP/SMTP tasks.

If IO is already running, nothing happens.

If the context was created by the dc_accounts_t account manager, use dc_accounts_start_io() instead of this function.

Parameters

context

The context object as created by dc_context_new().

dc_stop_io()

void dc_stop_io

(

dc_context_t *

context

)

Stop job, IMAP, SMTP and other tasks and return when they are finished.

Even if IO is not running, there may be pending tasks, so this function should always be called before releasing context to ensure clean termination of event loop.

If the context was created by the dc_accounts_t account manager, use dc_accounts_stop_io() instead of this function.

Parameters

context

The context object as created by dc_context_new().

dc_stop_ongoing_process()

void dc_stop_ongoing_process

(

dc_context_t *

context

)

Signal an ongoing process to stop.

After that, dc_stop_ongoing_process() returns without waiting for the ongoing process to return.

The ongoing process will return ASAP then, however, it may still take a moment.

Typical ongoing processes are started by dc_configure() or dc_imex(). As there is always at most only one onging process at the same time, there is no need to define which process to exit.

Parameters

context

The context object.

dc_str_unref()

void dc_str_unref

(

char *

str

)

Release a string returned by another deltachat-core function.

• Strings returned by any deltachat-core-function MUST NOT be released by the standard free() function; always use dc_str_unref() for this purpose.
• dc_str_unref() MUST NOT be called for strings not returned by deltachat-core.
• dc_str_unref() MUST NOT be called for other objects returned by deltachat-core.

Parameters

str	The string to release. If NULL is given, nothing is done.

dc_was_device_msg_ever_added()

int dc_was_device_msg_ever_added	(	dc_context_t *	context,
		const char *	label
	)

Check if a device-message with a given label was ever added.

Device-messages can be added with dc_add_device_msg().

Parameters

context	The context object.
label	The label of the message to check.

Returns

1=A message with this label was added at some point, 0=A message with this label was never added.

---

The documentation for this class was generated from the following file:

• deltachat.h