Join a Group

Join a Group

In order to start participating in group conversations, you will have to join a group. You can do so using the joinGroup() method.

Swift

let guid = "cometchat-guid-11";
let password = nil; // mandatory in case of password protected group type

CometChat.joinGroup(GUID: guid, groupType: .public, password: nil, onSuccess: { (group) in

  print("Group joined successfully. " + group.stringValue())

}) { (error) in

  print("Group joining failed with error:" + error!.errorDescription);
}

Objective C

NSString *guid = @"cometchat-guid-101";
NSString *password = nil ; // mandatory in case of password protected group type

[CometChat joinGroupWithGUID:guid groupType:groupTypePublic password:password onSuccess:^(Group * group) {

    // Success
    NSLog(@"Group joined successfully: %@",[group stringValue]);

} onError:^(CometChatException * error) {

    // Error
    NSLog(@"Group joining failed with exception: %@",[error errorDescription])
}];

The joinGroup() method takes four parameters

Parameter	Description
GUID	The GUID of the group you would like to join
groupType	Type of the group. CometChat provides 3 types of groups viz. .public .private .password
password	The password is mandatory in case of a .password protected the group.

Once you have joined a group successfully, you can send and receive messages in that group.

CometChat keeps a track of the groups joined and you do not need to join the group every time you want to communicate in the group.

You can identify if a group is joined using the hasJoined parameter in the Group object.

Real-time Group Member Joined Events

In other words, as a recipient, how do I know when someone joins a group?

To receive Real-Time Events for the same, you need to implement the onMemberAddedToGroup() method of the GroupListener class.

Swift

extension AppDelegate: CometChatGroupDelegate {

  func onMemberAddedToGroup(action: ActionMessage, addedBy: User, addedUser: User, addedTo: Group) {
      //When any member is added in the group this function will be called
  }

}

Objective C

@interface ViewController ()<CometChatGroupDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [CometChat setGroupdelegate:self];
}

- (void)onMemberAddedToGroup:(Action *)action addedBy:(User * _Nonnull)addedBy addedUser:(User * _Nonnull)addedUser addedTo:(Group * _Nonnull)addedTo {
    //When any member is added in the group this function will be called
}

@end

Missed Group Member Joined Events

In other words, as a member of a group, how do I know if someone joins the group when my app is not running?

When you retrieve the list of previous messages if a member has joined any group that the logged-in user is a member of, the list of messages will contain an Action message. An Action message is a sub-class of BaseMessage class.

For the group member joined the event, in the Action object received, the following fields can help you get the relevant information-

1. action - joined
2. actionBy - User object containing the details of the user who joined the group
3. actionFor - Group object containing the details of the group the user has joined