Join A Group

Join public or password-protected groups, listen for real-time join events, and handle missed join events using the CometChat React Native SDK.

Quick Reference - Join a group:

// Join a public group
await CometChat.joinGroup("GUID", CometChat.GROUP_TYPE.PUBLIC, "");

// Join a password-protected group
await CometChat.joinGroup("GUID", CometChat.GROUP_TYPE.PASSWORD, "password123");

Available via: SDK | REST API

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.

JavaScript

var GUID = "GUID";
var password = "";
var groupType = CometChat.GROUP_TYPE.PUBLIC;

CometChat.joinGroup(GUID, groupType, password).then(
group => {
  console.log("Group joined successfully:", group);
}, error => {
  console.log("Group joining failed with exception:", error);
}
);

TypeScript

var GUID: string = "GUID";

CometChat.joinGroup(GUID, CometChat.GroupType.Public).then(
  (group: CometChat.Group) => {
      console.log("Group joined successfully:", group);
  }, (error: CometChat.CometChatException) => {
      console.log("Group joining failed with exception:", error);
  }
);

The joinGroup() method takes the below 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. 1. CometChat.GROUP_TYPE.PUBLIC 2. CometChat.GROUP_TYPE.PASSWORD 3. CometChats.GROUP_TYPE.PRIVATE
password	Password is mandatory in case of a password protected group.

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

Response

On Success — joinGroup() returns a Group object:

Parameter	Type	Description	Sample Value
hasJoined	boolean	Whether the logged-in user has joined the group	true
membersCount	number	Total number of members in the group	2
isBanned	boolean	Whether the logged-in user is banned from the group	false
guid	string	Unique identifier of the group	"group_1772427551785"
name	string	Name of the group	"Comet Group"
type	string	Type of the group (public, private, password)	"public"
scope	string	Scope of the logged-in user in the group	"participant"
joinedAt	number	Unix timestamp when the user joined	1772427667
conversationId	string	Conversation ID for the group	"group_group_1772427551785"
createdAt	number	Unix timestamp when the group was created	1772427556
owner	string	UID of the group owner	"cometchat-uid-6"
onlineMembersCount	number	Number of online members in the group	1

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 member of a group, how do I know if someone joins the group when my app is running?

If a user joins any group, the members of the group receive a real-time event in the onGroupMemberJoined() method of the GroupListener class.

JavaScript

CometChat.addGroupListener(
  "UNIQUE_LISTNER_ID",
  new CometChat.GroupListener({
      onGroupMemberJoined: (message, joinedUser, joinedGroup) => {
          console.log("User joined", { message, joinedUser, joinedGroup });
      }
  })
);

TypeScript

CometChat.addGroupListener(
  "UNIQUE_LISTNER_ID",
  new CometChat.GroupListener({
      onGroupMemberJoined: (message: CometChat.Action, joinedUser: CometChat.User, joinedGroup: CometChat.Group) => {
          console.log("User joined", { message, joinedUser, joinedGroup });
      }
  })
);

Always remove group listeners when the component unmounts using CometChat.removeGroupListener(listenerId). Failing to remove listeners can cause memory leaks and duplicate event handling.

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 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

Best Practices

Check hasJoined before joining

Before calling joinGroup(), check the hasJoined property on the Group object. If the user has already joined, calling joinGroup() again will return an error.

Handle password-protected groups in your UI

For password-protected groups, prompt the user for the password before calling joinGroup(). Pass the password as the third parameter.

Troubleshooting

joinGroup fails for private groups

Private groups cannot be joined directly. Members must be added by an admin or owner using the group members API. Only public and password-protected groups support joinGroup().

Wrong password error for password group

Ensure the password string matches exactly. Passwords are case-sensitive. If the user enters an incorrect password, the SDK returns an error.

onGroupMemberJoined not firing

Verify the group listener is registered with addGroupListener() before the join event occurs. Also ensure the listenerId is unique and hasn’t been overwritten.

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Next Steps

Leave a Group

Leave groups and stop receiving updates

Group Members

Manage members, roles, and permissions within groups

Send Messages

Send text, media, and custom messages to groups

Retrieve Groups

Fetch group lists and group details