Friend Management

Overview
The Chat SDK supports friend management, and users can add and delete friends and set to send messages only to friends.
Getting the contacts
The Chat SDK supports the logic for the friend contacts. You can call the getFriendList API (details) to get contacts.
Sample code:
// Obtain the contacts
V2TimValueCallback<List<V2TimFriendInfo>> friendsList = await friendshipManager.getFriendList();
Adding friends
Call the addFriend API (details) to add a friend.
Sample code:
// Add a two-way friend
V2TimValueCallback<V2TimFriendOperationResult> addFriend = await friendshipManager.addFriend(userID: "userID",remark:"Friend request remarks",addWording:"Remarks",addType:FriendTypeEnum.V2TIM_FRIEND_TYPE_BOTH);
The process has the following variations depending on whether friend verification is required.
Friend request approval is not required
1. Users A and B call setFriendListener to set the contacts listener.
2. User B specifies that friend request approval is not required (V2TIM_FRIEND_ALLOW_ANY) through the allowType field (details) in the setSelfInfo function.
3. User A can add user B as a friend successfully by calling addFriend, after which the addType of the V2TIMFriendAddApplication request parameter can be set to either value as needed:
If it is set to V2TIM_FRIEND_TYPE_BOTH (two-way friend), both users A and B will receive the onFriendListAdded callback (details).
If it is set to V2TIM_FRIEND_TYPE_SINGLE (one-way friend), only user A will receive the onFriendListAdded callback.
Friend request approval is required
1. Users A and B call setFriendListener to set the contacts listener.
2. User B specifies that friend request approval is required (V2TIM_FRIEND_NEED_CONFIRM) through the allowType field in the setSelfInfo function. 
3. User A calls addFriend to request to add user B as a friend. The resultCode parameter in the callback for successful API call returns 30539, indicating that the request needs to be approved by user B. In addition, both users A and B will receive the onFriendApplicationListAdded callback (details).
4. User B will receive the onFriendApplicationListAdded callback. If type in the V2TIMFriendApplication parameter is V2TIM_FRIEND_APPLICATION_COME_IN, user B can accept or reject the request.
User B calls acceptFriendApplication API (details) to accept the friend request. If the type is V2TIM_FRIEND_ACCEPT_AGREE (one-way friend):
User A will receive the onFriendListAdded callback, indicating that the one-way friend was added successfully.
User B will receive the onFriendApplicationListDeleted callback (details). At this point, user B has become a friend of user A, but not vice versa.
User B calls acceptFriendApplication to accept the friend request. If the type is V2TIM_FRIEND_ACCEPT_AGREE_AND_ADD (two-way friend), both users A and B will receive the onFriendListAdded callback, indicating that they added each other as a friend successfully.
User B calls refuseFriendApplication API (details) to reject the friend request, and both users will receive the onFriendApplicationListDeleted callback.
Deleting friends
Call the deleteFromFriendList API (details) to delete a friend.
Sample code:
// Two-way deletion
V2TimValueCallback<List<V2TimFriendOperationResult>> deleteres = await friendshipManager.deleteFromFriendList(deleteType: FriendTypeEnum.V2TIM_FRIEND_TYPE_BOTH,userIDList:['user1']);
Checking friend relationships
Call the checkFriend API (details) to check the friend relationship.
Sample code:
// Check whether the friend relationship is one-way or two-way
V2TimValueCallback<List<V2TimFriendCheckResult>> checkres = await friendshipManager.checkFriend(checkType:FriendTypeEnum.V2TIM_FRIEND_TYPE_BOTH,userIDList: [] );
Setting to send messages to friends only
By default, Chat SDK does not check the relationship when sending one-to-one messages. This default setting is generally applied in customer service scenarios, where having to friend a customer service agent before chatting is inefficient.
If you want to implement the interaction mode of "friending before chatting", go to Chat console -> Feature Configuration -> Login and Message -> Relationship Check and enable "Check Relationship for One-to-One Messages". With this feature enabled, users can only send messages to friends, and will receive the 20009 error code from SDK when sending a message to a non-friend user.
Overview