Overview

SDK provides a complete set of messaging management services, including messaging, storing messages, uploading and downloading attachments, and managing recent contacts. It originally supports sending various types of messages, including text, audio, image, video, file, geographic location, reminder etc., and supports sending custom messages as well. For details of the messaging features, please refer to basic messaging features in the product introduction.

NIMMessageTypeMessage type

Enumeration	Value	Description
kNIMMessageTypeText	0	Text message
kNIMMessageTypekNIMMessageTypeImageText	1	Image message
kNIMMessageTypeAudio	2	Audio message
kNIMMessageTypeVideo	3	Video message
kNIMMessageTypeLocation	4	Location message
kNIMMessageTypeNotification	5	System notifications (including those for joining and exiting team, etc.)
kNIMMessageTypeFile	6	File message
kNIMMessageTypeTips	10	Reminder type message, content of which should be from the kNIMMsgKeyServerExt field in the message structure and filled in according to format requirements
kNIMMessageTypeRobot	11	AI robot messages (not yet available)
kNIMMessageTypeCustom	100	Custom message
kNIMMessageTypeUnknown	1000	Unknown type of message, it is the default value

NIMMessageFeatureMessage type

Enumeration	Value	Description
kNIMMessageFeatureDefault	0	Default
kNIMMessageFeatureLeaveMsg	1	Offline message
kNIMMessageFeatureRoamMsg	2	Roaming message
kNIMMessageFeatureSyncMsg	3	Default messages, which are synchronized to each terminal upon multi-terminal login
kNIMMessageFeatureCustomizedMsg	4	Passthrough message

MessageSettingMessage setting

Type	Parameter	Description
BoolStatus	resend_flag_	To resend message? Send for the first time:0, resend the message: 1
BoolStatus	need_push_	If push is needed, 1: yes, 0: no
BoolStatus	push_need_badge_	(Optional) Is counting needed for push message (corner mark), 1: yes, 0: no
BoolStatus	push_need_prefix_	(Optional) Whether push messages need prefixes, set to true by default
string	push_content_	Custom push content, with a length not exceeding 200 bytes
string	push_payload_	Custom push attributes, must be unformatted json string with a length limited to 2048
BoolStatus	server_history_saved_	(Optional) The message is once saved on the cloud? The default is 1, 1: yes, 0: no, if roaming and offline features are supported, then it must be set to 1
BoolStatus	roaming_	(Optional) Enable roaming for the message? The default is 1, 1: yes, 0: no
BoolStatus	self_sync_	(Optional) Enable multi-terminal sync for the message? The default is 1, 1: yes, 0: no
BoolStatus	routable_	(Optional) The message is copied? 0:no, 1:yes, follow app router configuration in default
BoolStatus	need_offline_	(Optional) Save messages offline? The default is 1, 1: yes, 0: no, if roaming is supported, then it must be set to 1
BoolStatus	anti_spam_enable_	Is Yidun anti-spam needed? 1: yes, 0: no
string	anti_spam_content_	(Optional) Anti-spam field customized by developer, length limit: 5000 characters, format: json string, {"type": 1: text, 2: image, 3 video, "data": "Text content or image address or video address"}
string	local_ext_	Local extension contents, local storage only, reserved field
string	server_ext_	Third-party extension field with a length limited to 1024
BoolStatus	is_force_push_	Force push switch for team message, with total force push set as true and force push list set as empty
std::list< std::string >	force_push_ids_list_	Force push team message list
string	force_push_content_	Text in force push team message

IMMessageBasic message contents

Type	Parameter	Description
NIMSessionType	session_type_	Session type, for details please refer to NIMSessionType
string	sender_accid_	Sender ID, filled out by server, which the sender may ignore
string	receiver_accid_	Receiver's ID (required), which should be your own ID when sending a message to yourself
NIMClientType	readonly_sender_client_type_	Sender client type, filled out by server, which the sender may ignore
string	readonly_sender_device_id_	Sender device ID, filled out by server, which the sender may ignore
string	readonly_sender_nickname_	Sender nickname, filled out by server, which the sender may ignore
int64_t	timetag_	Message timestamp (13-digit UNIX timestamp in milliseconds)
NIMMessageType	type_	Message type, see NIMMessageType for details
string	client_msg_id_	Message uuid, unique identifier, to be completed by sender
int64_t	readonly_server_id_	Server-side message ID, to be completed by server
MessageSetting	msg_setting_	Message setting, see MessageSettingfor details
string	local_res_path_	Local absolute path of multimedia message resource, managed by SDK locally and is required when sending multimedia messages. In case of image messages, when setting up thumbnail download, this path should be the local absolute path of the thumbnails
string	local_talk_id_	Session ID, optional for sender. The receiver receives the sender ID
string	local_res_id_	Session ID, optional for sender. The receiver receives the client message ID
NIMMsgLogStatus	status_	Local message status, see message status type for details)
NIMMsgLogSubStatus	sub_status_	(Local message sub-status, see message sub-status type for details)

Note: Roaming means that the messages that have been received at one terminal will be synchronized to other terminals (the most recent 100 messages stored on the server). Multi-terminal synchronization means that when multiple device platforms log in at the same time, a message sent by one terminal will be synchronously received by other terminals. Offline means if the receiver is offline when the message is sent, it can receive the message as soon as it goes online again.

Description of message settings:

	SavedOffline	ServerSaveHistory	Roaming	MultiSync
Offline message	1	1	optional	optional
Roaming message	1	1	1	optional
Multi-terminal message sync	optional	optional	optional	1

Send message

SDK supports common built-in messages types such as text, picture, voice, video, file, geographic location, reminder (NIMMessageType), as well as sending custom messages. At the same time, we also provide a stop sending interface, which is currently mainly used to stop sending file message that is being uploaded.

• API prototype

static void SendMsg(const std::string& json_msg, const std::string& json_extension = "", FileUpPrgCallback* pcb = nullptr);

• Parameter Description

Parameter	Description
json_msg	Message content, see IMMessage for details
json_extension	Extension field. Reserved
pcb	Notification of upload progress callback, which informs upload progress of self-uploaded attachments such as images, audio and video files (if any)

Message setting

Sending a message also involves the following message attribute settings (Corresponding fields are contained in MessageSetting):

• Messages can have two types of extension fields, namely server extension field kNIMMsgKeyServerExt and local extension field kNIMMsgKeyLocalExt. Each type features a maximum length of 1024 bytes. The server extension field will be sent to other terminals, while the local extension field is only valid locally. Both extension fields will be stored by the SDK in the database.

• Push text field (kNIMMsgKeyPushContent, with a maximum length of 200 bytes) and custom push attribute (kNIMMsgKeyPushPayload, with a maximum length of 2048 bytes), please pay attention to the maximum length. If push text is set, the text will be displayed in the notification bar when the message is received by the recipient, if not, then SDK's default text will be used.

• Whether push field is needed (kNIMMsgKeyPushEnable), 0: not needed, 1: needed.

• Whether message count field is needed (kNIMMsgKeyNeedBadge), 0: not needed, 1: needed.

• Whether push nickname is needed (kNIMMsgKeyNeedPushNick), 0: not needed, 1: needed.

• Whether to store the message in the cloud (kNIMMsgKeyHistorySave), if it is set to 0, the message cannot be obtained by calling the interface of server message history. 0: Not needed, 1: Needed.

• Whether the message supports roaming (kNIMMsgKeyMsgRoaming). If it is set to 1, even if a certain client has received the message, other clients can still obtain it by roaming when they log in again. 0: Not needed, 1: Needed.

• Whether the message supports multi-terminal synchronization (kNIMMsgKeyMsgSync). If it is set to 1, a message sent will be synchronized to other clients logged in at the same time. 0: Not needed, 1: Needed.

Team messages have forced push attributes (can be used to implement @ features, etc.):

• Whether force push field (kNIMMsgKeyIsForcePush)is needed, 0: not needed, 1: needed.

• Force push list field (kNIMMsgKeyForcePushList), should be filled in with the specified account ID string array json, and left empty if forced push is enabled for all.

• Text field (kNIMMsgKeyForcePushContent) in force push team message

Anti-spam field:

• The ID of the anti-spam rule specified by the developer for the message (kMsgTagAntiSpamBusinessId), should be the same as that on the server side

• Whether YiDun anti-spam is needed (kNIMMsgKeyAntiSpamEnable), 0: not needed, 1: needed.

• (Optional) Anti-spam field customized by developer (kNIMMsgKeyAntiSpamContent), length limit: 5000 characters, format: json string, {"type": 1: text, 2: image, 3 video, "data": "Text content or image address or video address"}

• Whether a single message uses YiDun anti-spam (kNIMMsgKeyAntiSpamUsingYiDun), 0: (YiDun activated) not passing YiDun anti-spam but general anti-spam, with all other matters still subject to original rules.

Text message

Create text message content, complete the necessary message setting and send the message through theSendMsginterface.

• API prototype

static std::string CreateTextMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const std::string& content, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
content	Text content
msg_setting	Message property settings
timetag	Current UNIX timestamp, in milliseconds

• Example

//In case of p2p message and test account test1
Json::FastWriter fw;
std::string content = "This is a text message." ;
//Message settings, to be configured as needed
//Other message settings, same as above
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//If anti-spam is needed
setting.anti_spam_enable_ = 1;
//Assemble anti-spam content
Json::Value jx;
jx["type"] = 1;
jx["data"] = content;//If it is a image or video, fill in the url of the attachment

setting.anti_spam_content_ = fw.write(jx);//Serialize to get json string

//Other settings
...

//Create message
std::string msg = nim::Talk::CreateTextMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",content,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Picture message

Create image message content, complete the necessary message setting and send the message through the SendMsg interface. The sent local image file will be automatically uploaded.

The attachment contentIMImageof the image message is derived from IMFile, the field of which contains description of

Type	Parameter	Field
int	width_	Image width
int	height_	Image height

• API prototype

static std::string CreateImageMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const IMImage& image, const std::string& file_path, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
image	Image attachment content, see IMImage for details
file_path	Path of the local image file, if the file exists, the SDK will upload it automatically
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
IMImage attachment;
attachment.md5_ = "0ca175b9c0f726a831d895e269332461";
attachment.size_ = 409600;
attachment.url_="http://xxxxxx/img.png";//If sending a local file, leave it blank
attachment.display_name_ = "img";
attachment.file_extension_ = "png";

//Set image height and width
attachment.width_ = 800;
attachment.height = 600;

//Local file path
std::string local_file_path = "c：\\img.png";

//Create message
std::string msg = nim::Talk::CreateImageMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",attachment,local_file_path,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Voice message

Create voice message content, complete the necessary message setting and send the message through theSendMsginterface. The sent local audio file will be automatically uploaded.

The attachment contentIMAudioof the voice message is derived from IMFile, the field of which contains description of

Type	Parameter	Field
int	duration_	Audio message duration

• API prototype

static std::string CreateAudioMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const IMAudio& audio, const std::string& file_path, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
audio	Audio attachment content, see IMAudio for details
file_path	Path of the local file, if the file exists, the SDK will upload it automatically
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
IMAudio attachment;
attachment.md5_ = "0ca175b9c0f726a831d895e269332461";
attachment.size_ = 409600;
attachment.url_="http://xxxxxx/audio.aac";//If sending a local file, leave it blank
attachment.display_name_ = "audio";
attachment.file_extension_ = "aac";

//Set the duration
attachment.duration_ = 8000;//ms

//Local file path
std::string local_file_path = "c：\\audio.aac";

//Create message
std::string msg = nim::Talk::CreateAudioeMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",attachment,local_file_path,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Video message

Create video message content, complete the necessary message setting and send the message through the SendMsg interface. The sent local video file will be automatically uploaded.

The attachment contentIMVideoof the video message is derived from IMFile, the field of which contains description of

Type	Parameter	Field
int	duration_	Audio message duration
int	width_	Image width
int	height_	Image height

• API prototype

static std::string CreateVideoMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const IMVideo& video, const std::string& file_path, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
video	Image attachment content, see IMVideo for details
file_path	Path of the local file, if the file exists, the SDK will upload it automatically
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
IMVideo attachment;
attachment.md5_ = "0ca175b9c0f726a831d895e269332461";
attachment.size_ = 409600;
attachment.url_="http://xxxxxx/video.mp4";//If sending a local file, leave it blank
attachment.display_name_ = "video";
attachment.file_extension_ = "mp4";

//Set the duration, length and width
attachment.duration_ = 8000;//ms
attachment.width_ = 800;
attachment.height = 600;

//Local file path
std::string local_file_path = "c：\\video.mp4";

//Create message
std::string msg = nim::Talk::CreateVideoMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",attachment,local_file_path,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Geographic location

Create location message content, complete the necessary message setting and send the message through the SendMsg interface.

The attachment contentNIMLocationMsgInfoof the location message contains description of

Type	Parameter	Field
string	description_	Location description
int	latitude_	Latitude
int	longitude_	Longitude

• API prototype

tatic std::string CreateLocationMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const IMLocation& location, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
location	Location attachment content, see IMLocation for details
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
IMLocation attachment;
//Set location name, latitude and longitude
attachment.description = "Hangzhou";
attachment.latitude_ = 30.3;
attachment.longitude_ = 120.2;

//Create message
std::string msg = nim::Talk::CreateLocationMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",attachment,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

File message

Create file message content, complete the necessary message setting and send the message through the SendMsg interface.

IMFileFile attachment base class

Type	Parameter	Field
string	md5_	md5 of the file content
int64_t	size_	File size, 64-bit integer
string	url_	http url of the file
string	display_name_	file name
string	file_extension_	File extension

• API prototype

static std::string CreateFileMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const IMFile& file, const std::string& file_path, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
file	File attachment content, see IMFile for details
file_path	Path of the local file, if the file exists, the SDK will upload it automatically
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
IMFile attachment;
attachment.md5_ = "0ca175b9c0f726a831d895e269332461";
attachment.size_ = 409600;
attachment.url_="http://xxxxxx/document.doc";//If sending a local file, leave it blank
attachment.display_name_ = "Document";
attachment.file_extension_ = "doc";


//Local file path
std::string local_file_path = "c:\\document.doc";

//Create message
std::string msg = nim::Talk::CreateFileMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",attachment,local_file_path,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Tip message

Create reminder message content, complete the necessary message setting and send the message through the SendMsg interface. If sending to server is not needed, the developer can use the insert local message to store the message in the database and update the session class table.

• API prototype

static std::string CreateTipMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const std::string& tip_content, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
receiver_id	A user account is used in one-on-one chat; a team ID is used in a group chat
session_type	Session type
client_msg_id	Client message ID, uuid is recommended
tip_content	Reminder message content, defined and parsed by developer
msg_setting	Message property settings
timetag	Current UNIX timestamp in milliseconds

• Example

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

std::string tip_content = "This is a reminder message";

//Create message
std::string msg = nim::Talk::CreateTipMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",content,setting,1520500638234);

//Send message (or in some scenarios, use nim::MsgLog::WriteMsglogToLocalAsync to directly write local data)
nim::Talk::SendMsg(msg,null);

Custom message

Create custom message content, complete the necessary message setting and send the message through the SendMsg interface. SDK will not parse the specific content of custom messages, and the corresponding work should be assumed by the developer. SDK will save custom message to message database, which will be shown in message history together with built-in message.

• Example

std::string CreateCustomMessage(const std::string& receiver_id, const NIMSessionType session_type, const std::string& client_msg_id, const std::string& content, const std::string& attachment, const MessageSetting& msg_setting, int64_t timetag/* = 0*/)
{
	Json::Value values;
	values[kNIMMsgKeyToAccount] = receiver_id;
	values[kNIMMsgKeyToType] = session_type;
	values[kNIMMsgKeyClientMsgid] = client_msg_id;
	values[kNIMMsgKeyBody] = content;
    values[kNIMMsgKeyAttach] = attachment; //Custom attachment content;
	values[kNIMMsgKeyType] = kNIMMessageTypeCustom;//Custom message
	values[kNIMMsgKeyLocalTalkId] = receiver_id;

	msg_setting.ToJsonValue(values);

	//Optional
	if (timetag > 0)
		values[kNIMMsgKeyTime] = timetag;

	Json::FastWriter fw;
	return fw.write(values);
}

//In case of p2p message and test account test1
//Message settings, to be configured as needed
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

//Other settings
...

//Assemble attachment content
Json::FastWriter fw;
Json::Value attachment;
attachment["customFiled1"] = "Custom content 1";
attachment["customFiled2"] = 10; //Custom value


std::string contemt = "This is normal text content";

//Create message
std::string msg = CreateCustomMessage("test1",kNIMSessionTypeP2P,"Generate your own unique uuid",contemt,fw.write(attachment),setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Team force push message

Send a force push message to the team to @ the specified person or everyone, see MessageSettingfor details

• Example

//Take test team 1222222 as an example
Json::FastWriter fw;
std::string content = "This is a text message." ;
//Message settings, to be configured as needed
//Other message settings, same as above
MessageSetting setting;
setting.roaming_ = 1;
setting.need_offline_ = 1;
setting.server_history_saved_ = 1;

...

//Force push to team members test1, test2
setting.is_force_push_ = 1;
setting.force_push_ids_list_.push_back("test1");
setting.force_push_ids_list_.push_back("test2");
setting.force_push_content_ = "This is a force push message";

//Other settings
...

//Create message
std::string msg = nim::Talk::CreateTextMessage("1222222",kNIMSessionTypeTeam,"Generate your own unique uuid",content,setting,1520500638234);

//Send message
nim::Talk::SendMsg(msg,null);

Sending result notification

Sending is successful or failed, and the result also contains tag (if any) for client anti-spam hit.

SendMessageArcParameter description

Type	Parameter	Description
string	talk_id_	Session ID
string	msg_id_	Message ID
NIMResCode	rescode_	Error code
int64_t	msg_timetag_	Message timestamp
bool	client_anti_spam_hit_	Is there a hit with client anti-spam, 1: Yes, 0: No

• API prototype

static void RegSendMsgCb(const SendMsgAckCallback& cb, const std::string& json_extension = "");

• Example

//Monitor event
nim::Talk::RegSendMsgCb([&](const nim::SendMessageArc& ack) 
{
    ...
});

//Cancel monitoring
nim::Talk::RegSendMsgCb(nullptr);

Stop sending message

Stop sending message. Currently it only can be used on file messages, meaning sending can be terminated during file upload. It can't be used on a file that has already been uploaded.

• API prototype

 public static void StopSendMessage(NIMIMMessage message, ReportUploadProgressDelegate action = null);

• Parameter Description

Parameter	Description
message	Structure of the message to be stopped
action	Reserved, not in use for now

• Example

//The unique uuid of the message to be stopped, required
std::string clientMsgId = "uuid";

//Interrupt sending
nim::Talk::StopSendMsg(clientMsgId, kNIMMessageTypeFile);

Receive message

The developer needs to register the event monitoring of message reception before logging in to the SDK. Message receiving covers online, offline, synchronized, roaming messages, etc. If a multimedia message is received, the SDK will automatically download attachments in the background by default. In case of voice message, the audio file will be downloaded directly. In case of image message, only the thumbnail will be downloaded, and you can get the original image through the download interface.

Message parsing

SDK supports parsing of built-in messages such as images, files, audio, video, geographic locations, etc. Other custom messages and attachments need to be parsed by the developer.

1. Parse message content

• API prototype

static bool ParseIMMessage(const std::string& json_msg, IMMessage& msg);

• Parameter Description

Parameter	Description
json_msg	Input the unformatted json string of message content
msg	Output message content, see IMMessage for details

2. Parse received message

Different from Parsing message content , this function parses fieldskNIMMsgKeyLocalRescode, kNIMMsgKeyLocalMsgFeatureandkNIMMsgKeyLocalReceiveMsgContent,whileParseIMMessageparses actual message content carried bykNIMMsgKeyLocalReceiveMsgContent.

• API prototype

static bool ParseReceiveMessage(const std::string& json_msg, IMMessage& msg);

• Parameter Description

Parameter	Description
json_msg	Input the unformatted json string of message content
msg	Output message content, see IMMessage for details

3. Parse image message attachment

• API prototype

static bool ParseImageMessageAttach(const IMMessage& msg, IMImage& image);

• Parameter Description

Parameter	Description
msg	Message content, see IMMessage for details
image	Output image attachment content, see IMImage for details

4. Parse file message attachment

• API prototype

static bool ParseFileMessageAttach(const IMMessage& msg, IMFile& file);

• Parameter Description

Parameter	Description
msg	Message content, see IMMessage for details
file	Output image attachment content, see IMFile for details

5. Parse voice message attachment

• API prototype

static bool ParseAudioMessageAttach(const IMMessage& msg, IMAudio& audio);

• Parameter Description

Parameter	Description
msg	Message content, see IMMessage for details
audio	Output image attachment content, see IMAudio for details

6. Parse video message attachment

• API prototype

static bool ParseVideoMessageAttach(const IMMessage& msg, IMVideo& video);

• Parameter Description

Parameter	Description
msg	Message content, see IMMessage for details
video	Output image attachment content, see IMVideo for details

7. Parse location message attachment

• API prototype

static bool ParseLocationMessageAttach(const IMMessage& msg, IMLocation& location);

• Parameter Description

Parameter	Description
msg	Message content, see IMMessage for details
location	Output image attachment content, see IMLocation for details

Online message receiving

It is recommended to register a global callback, so that the SDK only stores onecb, registering multiple callbacks will result in overwriting, and only the last one will take effect.

• API prototype

static void RegReceiveCb(const ReceiveMsgCallback& cb, const std::string& json_extension = "");

• Parameter Description

Parameter	Description
cb	Asynchronous notification callback
json_extension	Extension field. Reserved

• Example

//Monitor event
nim::Talk::RegReceiveCb([&](const IMMessage& msg) {
    //for test;
    switch (msg.type_)
    {
        case kNIMMessageTypeFile:
        {
            IMFile file;
            if (nim::Talk::ParseFileMessageAttach(msg, file))
            {
                ...
            }
        }
           break;
        case kNIMMessageTypeImage:
        {
            IMImage img;
            if (nim::Talk::ParseImageMessageAttach(msg, img))
            {
                ...
            }
        }
            break;
        case kNIMMessageTypeAudio:
        {
            IMAudio audio;
            if (nim::Talk::ParseAudioMessageAttach(msg, audio))
            {
                ...
            }
        }
            break;
        case kNIMMessageTypeVideo:
        {
            IMVideo video;
            if (nim::Talk::ParseVideoMessageAttach(msg, video))
            {
                ...
            }
        }
            break;
         case kNIMMessageTypeLocation:
        {
            IMLocation location;
            if (nim::Talk::ParseLocationMessageAttach(msg, location))
            {
                ...
            }
        }
            break;
        default:
        {
            std::string attach = msg.attach_;
            if (!attach.empty())
            {
                ...
            }
        }
        break;
    }

});

//Cancel monitoring
nim::Talk::RegReceiveCb(nullptr);

Receive offline, sync, and roaming messages

Receive batch messages, such as offline, roaming, and synchronized bulk messages. If this batch interface is also registered while registering receive message callback, when there are incoming batch messages, this interface will be used to notify the application. For example, for offline messages received after logging in, etc., the event monitoring must be registered before logging in.

• API prototype

public static void RegReceiveBatchMessagesCb(ReceiveBatchMesaagesDelegate cb)

• Parameter Description

Parameter	Description
cb	Callback of batch messages

• Example

//Monitor event
nim::Talk::RegReceiveMessagesCb([&](const std::list<IMMessage>& msgs) {
    for (auto  msg : msgs)
    {
        ...
    }
});

//Cancel monitoring
nim::Talk::RegReceiveMessagesCb(nullptr);

Filter team notifications

Register the callback for whether to filter the incoming team notifications. If this callback returns true, the SDK deems the notification as processed, therefore the SDK will not deliver the notification through the message reception channel, and will not save the notification to the local database.

• API prototype

public static void RegTeamNotificationFilterCb(TeamNotificationFilterDelegate action);

• Parameter Description

Parameter	Description
action	Callback for filtering team notifications

• Example

bool filterTeamNotify = true;
//Monitor event
nim::Talk::RegTeamNotificationFilter([&](const IMMessage& msg)->bool
{
	//If the notification is filtered, returns true, otherwise returns false;
    if (filterTeamNotify)
    {
        ...
        return true;
    }
    return false;
});

//Cancel monitoring
NIM.TalkAPI.RegTeamNotificationFilterCb(null);

Forward message

The user gets a new message object via construction API, and then calls the message sending interface.

• API prototype

static std::string CreateRetweetMessage(const std::string& src_msg_json, const std::string& client_msg_id, const NIMSessionType retweet_to_session_type, const std::string& retweet_to_session_id, const MessageSetting& msg_setting, int64_t timetag = 0);

• Parameter Description

Parameter	Description
src_msg_json	Content of the received message, the same as that of IMMessage
client_msg_id	New message uuid generated
retweet_to_session_id	The other party's ID, forwarded, user account or team ID
retweet_to_session_type	Session type, 0: p2p message 1: team message
msg_setting	Message setting, see message setting description for details
timetag	Current timestamp (in milliseconds)

• Example

//Assumed to be the content of the message sent or received by srcMsg
std:string srcMsg;

//Message settings, to be configured as needed
MessageSetting msgSetting;
msgSettting.ServerSaveHistory = true;
...

//A new message generated through srcMsg.
int64_t timeNow = 1520500638234;//Current UNIX timestamp in milliseconds
string sessionid = "1222222";
string clientMsgID = "uuid2";//A generated new unique uuid;
NIMSessionType sessionType = kNIMSessionTypeTeam;
std::string newMsg = nim::Talk::CreateRetweetMessage(srcMsg,clientMsgID,sessionType,sessionid,msgSettting,timeNow);

nim::Talk::SendMsg(newMsg,null);

Recall message

Sender, team owner and manager can perform recall through this interface (not applicable to chat room messages). This operation is generally time-limited (subject to global APP settings), and 508 is returned if the limit is exceeded. By registering callback notification for message recall, the developer receives notifications of message recalls on other clients. After receiving the notification, the SDK will mark the message as deleted in the message history. At the same time, the developer deletes the message displayed on the interface and can even insert a corresponding prompt if needed. For related development examples, refer to IM Demo.

RecallNotificationParameter description

Type	Parameter	Description
NIMSessionType	session_type_	Session type, 0: p2p message 1: team message
string	from_id_	Message from ID
string	to_id_	Message to ID
string	msg_id_	Unique ID of the message
string	notify_	Custom notification copy
int64_t	notify_timetag_	Timestamp of recall operation (in milliseconds)s
NIMMessageFeature	notify_feature_	Type of the recalled message, see NIMMessageFeature for details
bool	msglog_exist_	Whether the recalled message exists locally. For example, if the other party sent and recalled a message while offline, then the other party gets an offline recall notification after going online, the tag should be false
int64_t	msglog_timetag_	Timestamp of the message to be recalled (in milliseconds) (milliseconds)
string	from_nick_	Nickname of the sender of the message to be recalled

Active message recall

To recall messages that have been sent successfully, which relies on local history. It is required to find the message in local history according to its message id, if not the message can't be recalled.

• API prototype

static void RecallMsg(const IMMessage& msg, const std::string& notify, const RecallMsgsCallback& cb, const std::string& json_extension = "");

• Parameter Description

Parameter	Description
msg	To-be-recalled message
notify	Custom notification
cb	Callback notification of message recall
json_extension	Notification extension, reserved

• Example

//To be assembled by yourself, currently the recall is done through msgId,
IMMessage assembleMsg；
assembleMsg.client_msg_id_ = "Recalled message's uuid"; //only the message ID is used for now;
nim::Talk::RecallMsg(assembleMsg,"This is a recall notification", [&](NIMResCode code, const std::list<RecallMsgNotify>& notifications) {
	...
});

Message recall notification

Notify the user that the message has been recalled, this notification is available offline.

• API prototype

static void RegRecallMsgsCallback(const RecallMsgsCallback& cb, const std::string& json_extension = "");

• Parameter Description

Parameter	Description
cb	Callback of message recall notification
json_extension	Notification extension, reserved

• Example

//Monitor event
nim::Talk::RegRecallMsgsCallback([&](const NIMResCode code, const std::list<RecallMsgNotify>& notifications)
{
    for (auto  msg : notifications)
    {
        ...
    }
});

//Cancel monitoring
nim::Talk::RegRecallMsgsCallback(nullptr);

---

Read receipt

CommsEase provides read receipts of point-to-point messages. Note: This feature is only valid for P2P messages.

In the session interface, the operation of calling the interface for sending the read receipt and inputting the last message means that all the previous messages have been read, and the other side will receive the receipt.

General application scenarios for sending message read receipts:

1. Entering P2P chat interface (if you repeatedly enters the interface without receiving a new message, SDK can automatically filter repeated interface calls, so that only one of them is sent to the CommsEase server).

2. When you are in the chat interface and receive a new message from the current session.

Send read receipt

• API prototype

 static void SendReceiptAsync(const std::string& json_msg, const MessageStatusChangedCallback& cb);

• Parameter Description

Parameter	Description
json_msg	Message content received
cb	The callback notification of message status change after sending the message read receipt

• Example

//Assuming msg is a message that requires sending read receipt.
nim::MsgLog::SendReceiptAsync(msg, [&](const nim::MessageStatusChangedResult& result) {
    for (auto r : result.results_)
    {
        ...
    }
});

Monitor read receipt notification

Read receipt also represents a change in message status and therefore can be reflected in global message status change notification

Monitor broadcast to all notifications

Receive broadcast to all notifications. There are two types: individual and batch broadcast to all notifications. In general, batch notifications include offline broadcasts, synchronous broadcasts, and roaming broadcasts delivered when logging in.

BroadcastMessageDescription of broadcast notification parameters

Type	Parameter	Description
int64_t	id_	Notification message ID
string	from_id_	Sender account, can be empty
int64_t	time_	Notification message's UNIX timestamp, in milliseconds
string	body_	Notification content

1. Callback for receiving Individual broadcast to all notification , recommended to register it globally, so that messages can be distributed to specific sessions after accepting callbacks as a whole.

• API prototype

 static void RegReceiveBroadcastMsgCb(const ReceiveBroadcastMsgCallback& cb, const std::string& json_extension = "");

• Parameter Description

Parameter	Description
cb	Notification callback
json_extension	Extension field. Reserved

• Example

//Monitor event
nim::Talk::RegReceiveBroadcastMsgCb([&](const BroadcastMessage& msg)
{
	//Process broadcast notification
	...
});
//Cancel monitoring
nim::Talk::RegReceiveBroadcastMsgCb(nullptr);

2. Batch broadcast to all notifications

Callback for receiving batch broadcast messages. If this batch interface is also registered while registering receive message callback, when there are incoming batch messages, including offline messages received after logging in, this interface will be used to notify the application.

• API prototype

static void RegReceiveBroadcastMsgsCb(const ReceiveBroadcastMsgsCallback& cb, const std::string& json_extension = "");

• Parameter Description

Parameter	Description
cb	Callback of batch messages
json_extension	Extension field. Reserved

• Example

//Monitor event
nim::Talk::RegReceiveBroadcastMsgsCb([&](const std::list<nim::BroadcastMessage> msgs)
{
	//Process broadcast notification
    for (auto msg : msgs)
    {
        ...
    }
});
//Cancel monitoring
nim::Talk::RegReceiveBroadcastMsgsCb(nullptr);

Get local path from message attachment

Get local paths of message attachments (image, voice, video, etc.). If pre-loaded only thumbnails without downloading the original images, files in the path obtained here may not exist, and the developer needs download them by callingnim::NOS::FetchMedia. If thumbnail is preloaded according to global setting and the original image is needed, then before passing in the message content, the fieldlocal_res_path_should be set to blank or a custom save path.

• API prototype

static std::string GetAttachmentPathFromMsg(const IMMessage& msg);

• Parameter Description

Parameter	Description
msg	Message content to be obtained

• Example

//Assuming msg is a message to be obtained
std::string filePath = nim::Talk::GetAttachmentPathFromMsg(msg);

//Download original image
msg.local_res_path_ = ""; //Set it to blank or a custom save path;
nim::Talk::FetchMedia(msg,[&](NIMResCode res_code, const std::string& file_path, const std::string& call_id, const std::string& res_id){
	//Notification completed
	...
},[&](int64_t completed_size, int64_t file_size){
	//Notification progress
    ...
});

Get image thumbnail

In default, after receiving an image message, CommsEase PC SDK will pre-load the original image and put it into the local cache. If you want to control the quality of downloaded images, you can do so by configuringkNIMPreloadImageQuality(for quality control) andkNIMPreloadImageResize(for size control) when initializing the SDK. The IM Demo's development example downloads original images by default. Therefore, in case of development using source codes of IM Demo, you need to download the original images for image preview or other links that need to use original images.

In scenes including but not limited to the following, developers can download thumbnails by themselves:

• There are special requirements on image size
• Received picture messages in chat room

Currently SDK provides two schemes for obtaining thumbnails:

• To update image quality

  After receiving the image message, the user can obtain the download address of the image by parsing the content of attachmentkNIMMsgKeyAttach(kNIMChatRoomMsgKeyAttachif chat room message), and then obtain the image of specified quality based on parameters for splicing download interface: Download address is http(s)://?imageView&quality=N; http(s)://xxx; where N is image quality, with a range of 0 to 100.

• The image is intra-shrunk by length and width (in proportion to the original size, with the obtained image having "one side of the requested length, and the other of less than or equal to the requested length")

  After receiving an image message, users can obtain the download address of the image by parsing the content of attachment kNIMMsgKeyAttach (kNIMChatRoomMsgKeyAttach if chat room message), and then obtain the thumbnail based on parameters for splicing download interface: http(s)://xxx?imageView&thumbnail=XxY; http(s)://xxx is the image download address; where X is the width, Y is the height, and the middle symbol is the lowercase x. The value of width and height vary within the range of 0-4096.

  Variations of several parameters: 1. XxY: general (intra) shrink 2. Xx0: fixed width and adaptive height (intra shrink) 3. 0xY: fixed height and adaptive width (intra shrink)

Currently in IM Demo project, images displayed in messages are all compressed, for details refer to bubble_image.cpp