In-app Chat(Windows) Offline login

Function introduction

Offline login is typically used when the application is cleared from memory, and the user relaunches the application by clicking on the application icon. In this scenario, the user can directly access the local SDK data without network connectivity or a successful login.

Note

Users can only perform an offline login using the UserID from their previous successful login; otherwise, the login will not succeed.

Technical principle

When the offline login interface is called, the ZIM SDK performs verification (UserID verification; if token-based login is used, it also verifies the token's validity period). After successful verification, the SDK returns a login success callback, allowing users to query local data, while the SDK internally attempts to establish a connection with the backend service automatically.

Procedure

1. Log in to the app in offline status

In scenarios where there is no network connectivity and the application has been cleared from memory, you can make use of login interface. Set the isOfflineLogin in ZIMLoginConfig to trueto achieve offline login using the user information from the previous session. Once the login is confirmed as successful through the ZIMLoggedInCallback , you can then access the local SDK data.

Note

We recommend that you cache user information for each login. If the app is opened, the following logic is implemented when reading the cache:

If the user does not log in with the UserID for the previous online login, isOfflineLogin should be false. In this case, offline login is not supported, and local data of the SDK is inaccessible.
If the user logs in with the UserID for the previous online login, isOfflineLogin should be true to implement automatic login, accelerated access to the app homepage, and UI rendering in advance. In this case, offline login is supported.

// This login method is new, and the original method is no longer maintained since ZIM SDK 2.13.0.
virtual void login(const std::string &userID, const ZIMLoginConfig &config,
                    ZIMLoggedInCallback callback) = 0;

// This login method is new, and the original method is no longer maintained since ZIM SDK 2.13.0.
virtual void login(const std::string &userID, const ZIMLoginConfig &config,
                    ZIMLoggedInCallback callback) = 0;

Parameter	Type	Required	Description
userID	const std::string &	Yes	The user ID for the previous online login. It can contain up to 32 bytes in length, including digits, letters, and the following characters: '!', '#', '$', '%', '&', '(', ')', '+', '-', ':', ';', '< ', '= ', '. ', '> ', '?', '@', '[', ']', '^', '_', '{','}' '\|', '~'.
config	const ZIMLoginConfig &	Yes	Login configuration.
callback	ZIMLoggedInCallback	Yes	The login operation callback.

The following table describes the parameters in the ZIMLoginConfig class that are used to configure the config parameter.

Parameter	Type	Required	Description
userName	std::string	No	The username, which can contain up to 256 bytes in length. If the value is empty, the `UserName` for the previous login is used.
token	std::string	No	The token. This parameter is required for token-based authentication. Do not specify it for AppSign-based authentication.
isOfflineLogin	bool	No	Specifies whether this login is offline login. If the value is empty, the login is online login.

Sample call

zim::ZIMLoginConfig config;
config.userName = user_name;
// Do not specify this parameter for AppSign-based authentication.
config.token = token;
config.isOfflineLogin = true;

zim_sdk->login("user_id", config, [=](const zim::ZIMError &errorInfo) {
    if (errorInfo.code == zim::ZIMErrorCode::ZIM_ERROR_CODE_SUCCESS) {
        // Offline login is successful, and local data of the SDK can be queried.
    }
}];

zim::ZIMLoginConfig config;
config.userName = user_name;
// Do not specify this parameter for AppSign-based authentication.
config.token = token;
config.isOfflineLogin = true;

zim_sdk->login("user_id", config, [=](const zim::ZIMError &errorInfo) {
    if (errorInfo.code == zim::ZIMErrorCode::ZIM_ERROR_CODE_SUCCESS) {
        // Offline login is successful, and local data of the SDK can be queried.
    }
}];

2. Access local data of the SDK

After successful offline login, the following methods of the ZIM SDK 2.15.0 or earlier can be called when the network is disconnected.

Category	Method
User	queryUsersInfo querySelfUserInfo queryGroupApplicationList queryBlacklist checkUserIsInBlackList searchLocalFriends queryFriendsInfo queryFriendList queryFriendApplicationList
Group	queryGroupList searchLocalGroups queryGroupInfo queryGroupAttributes queryGroupAllAttributes queryGroupMemberList searchLocalGroupMembers queryGroupMemberInfo queryGroupMemberCount queryGroupMemberMutedList
Message	queryHistoryMessage updateMessageLocalExtendedData searchLocalMessages searchGlobalLocalMessages insertMessageToLocalDB deleteAllMessage：Only messages in the local database can be deleted. deleteMessages：Only messages in the local database can be deleted. deleteAllConversationMessages：Only messages in the local database can be deleted. queryMessageReceiptsInfo queryMessageReactionUserList queryGroupMessageReceiptReadMemberList queryGroupMessageReceiptUnreadMemberList importLocalMessages exportLocalMessages
Call invitation	queryCallInvitationList
Conversation	queryConversation queryConversationList queryConversationPinnedList searchLocalConversations clearConversationUnreadMessageCount clearConversationTotalUnreadMessageCount deleteConversation：Only conversations in the local database can be deleted. deleteAllConversations：Only conversations in the local database can be deleted. setConversationDraft
Cache management	clearLocalFileCache queryLocalFileCache

Listen for the onConnectionStateChanged event to obtain the status of connection between the ZIM SDK and the ZIM backend.

After a successful offline login, the value of ZIMConnectionState in onConnectionStateChanged is Connecting (enumeration value: 1).

You can call network methods to synchronize backend data only when the ZIM SDK automatically connects to the ZIM backend upon network reconnection and the value of ZIMConnectionState in onConnectionStateChanged is Connected (enumeration value: 2).

Offline login