Retrieve Groups

Fetch the groups a user has joined or can join, filter them by keyword or tag, and get one group’s details and online member count.

​

Retrieve List of Groups

In other words, as a logged-in user, how do I retrieve the list of groups I’ve joined and groups that are available?

In order to fetch the list of groups, you can use the GroupsRequest class. To use this class i.e to create an object of the GroupsRequest class, you need to use the GroupsRequestBuilder class. The GroupsRequestBuilder class allows you to set the parameters based on which the groups are to be fetched.

​

Set Limit

This method sets the limit i.e. the number of groups that should be fetched in a single iteration.

Java

GroupsRequest groupsRequest = new GroupsRequest.GroupsRequestBuilder()
.setLimit(limit)
.build();

Kotlin

val groupsRequest = GroupsRequestBuilder()
.setLimit(limit)
.build()  

​

Set Search Keyword

With offline support on, this filter is answered by the server only; the cached page is empty.

This method allows you to set the search string based on which the groups are to be fetched.

Java

GroupsRequest groupsRequest = new GroupsRequest.GroupsRequestBuilder()
.setSearchKeyWord("abc")
.build();

Kotlin

val groupsRequest = GroupsRequestBuilder()
.setSearchKeyWord("abc")
.build()

​

Joined Only

This method when used, will ask CometChat to only return the groups that the user has joined or is a part of.

Java

GroupsRequest groupsRequest = new GroupsRequest.GroupsRequestBuilder()
.joinedOnly(true)
.build();

Kotlin

val groupsRequest = GroupsRequestBuilder()
.joinedOnly(true)
.build()  

​

Set Tags

This method accepts a list of tags based on which the list of groups is to be fetched. The list fetched will only contain the groups that have been tagged with the specified tags.

Java

List<String> tags = new ArrayList<>();
tags.add("tag1");
tags.add("tag2");
GroupsRequest groupsRequest = new GroupsRequest.GroupsRequestBuilder()
.setLimit(limit)
.setTags(tags)
.build();  

Kotlin

val tags: MutableList<String> = ArrayList()
tags.add("tag1")
tags.add("tag2")
val groupsRequest = GroupsRequestBuilder()
.setLimit(limit)
.setTags(tags)
.build()

​

With Tags

This property when set to true will fetch tags data along with the list of groups.

Java

GroupsRequest groupsRequest = new GroupsRequest.GroupsRequestBuilder()
.setLimit(limit)
.withTags(true)
.build();

Kotlin

val groupsRequest = GroupsRequestBuilder()
.setLimit(limit)
.withTags(true)
.build()

Finally, once all the parameters are set to the builder class, you need to call the build() method to get the object of the GroupsRequest class.

Once you have the object of the GroupsRequest class, you need to call the fetchNext() method. Calling this method will return a list of Group objects containing N number of groups depending on the limit set.

The list of groups fetched will only have the public and password type groups. The private groups will only be available if the user is a member of that private group.

Starting with v5.1.0, the CallbackListener overload of `fetchNext()` is deprecated. Use `GroupFetchListener` instead; it requires SDK 5.1.0 or later, so on 5.0.x keep using CallbackListener. With offline support off, it behaves exactly like the old callback: onError is unchanged, and the server result arrives in the onServer… callback instead of onSuccess. With offline support on, it also delivers the cached result first; the old overload keeps working but receives only the server result. See Show Cached Data.

Java

private GroupsRequest groupsRequest = null;
private int limit = 30;

groupsRequest = new GroupsRequest.GroupsRequestBuilder().setLimit(limit).build();

groupsRequest.fetchNext(new CometChat.GroupFetchListener() {
@Override
public void onCachedGroups(List<Group> groups) {
  // Cached page: fires first (even when empty). Render immediately.
  Log.d(TAG, "Cached groups: " + groups.size());
}
@Override
public void onServerGroups(List<Group> groups) {
  // Server page: reconcile your displayed list, keyed by guid.
  Log.d(TAG, "Server groups: " + groups.size());
}
@Override
public void onError(CometChatException e) {
  Log.d(TAG, "Groups list fetching failed with exception: " + e.getMessage());
}
});

Kotlin

val limit = 30
val groupsRequest = GroupsRequestBuilder().setLimit(limit).build()

groupsRequest.fetchNext(object : CometChat.GroupFetchListener() {
override fun onCachedGroups(groups: List<Group>) {
  // Cached page: fires first (even when empty). Render immediately.
  Log.d(TAG, "Cached groups: " + groups.size)
}

override fun onServerGroups(groups: List<Group>) {
  // Server page: reconcile your displayed list, keyed by guid.
  Log.d(TAG, "Server groups: " + groups.size)
}

override fun onError(e: CometChatException) {
  Log.d(TAG, "Groups list fetching failed with exception: " + e.message)
}
})

​

Retrieve Particular Group Details

In other words, as a logged-in user, how do I retrieve information for a specific group?

To get the information of a group, you can use the getGroup() method.

Java

private String GUID = "GUID";

CometChat.getGroup(GUID, new CometChat.CallbackListener<Group>() {
@Override
public void onSuccess(Group group) {
  Log.d(TAG, "Group details fetched successfully: " + group.toString());        
}

@Override
public void onError(CometChatException e) { 
  Log.d(TAG, "Group details fetching failed with exception: " + e.getMessage());   

}
});

Kotlin

val GUID : String = "GUID"

CometChat.getGroup(GUID,object :CometChat.CallbackListener<Group>(){
override fun onSuccess(p0: Group?) {
  Log.d(TAG, "Group details fetched successfully: " + p0?.toString())
}
override fun onError(p0: CometChatException?) {
  Log.d(TAG, "Group details fetching failed with exception: " +p0?.message)
}
})

Parameter	Description
GUID	The GUID of the group for whom the details are to be fetched

On success, the Group object containing the details of the group is returned.

​

Get online group member count

To get the total count of online users in particular groups, you can use the getOnlineGroupMemberCount() method.

Java

List<String> guids = new ArrayList<>();
guids.add("cometchat-guid-1");
guids.add("cometchat-guid-11");

CometChat.getOnlineGroupMemberCount(guids, new CometChat.CallbackListener<HashMap<String, Integer>>() {
@Override
public void onSuccess(HashMap<String, Integer> stringIntegerHashMap) {
  Log.d(TAG, "Online count fetched successfully " + stringIntegerHashMap.toString());
}

@Override
public void onError(CometChatException e) {
  Log.d(TAG, e.getMessage());
}
});

Kotlin

val guids: MutableList<String> = ArrayList()
guids.add("cometchat-guid-1")
guids.add("cometchat-guid-11")

CometChat.getOnlineGroupMemberCount(guids, object : CallbackListener<HashMap<String?, Int?>>() {
override fun onSuccess(stringIntegerHashMap: HashMap<String?, Int?>) {
  Log.d(TAG, "Online count fetched successfully $stringIntegerHashMap")
}

override fun onError(e: CometChatException) {
  Log.d(TAG, e.message!!)
}
})

This method returns a Hashmap with the GUID of the group as the key and the online member count for that group as the value.

​

Offline Behaviour

With offline support enabled, GroupsRequest.fetchNext() on a GroupFetchListener first delivers onCachedGroups from the device (empty when nothing was recorded), then onServerGroups with the live page to reconcile by guid. Offline, the read ends with onError with code ERROR_INTERNET_UNAVAILABLE after the cached page. A request that uses a server-only filter records nothing, so its cached page is always empty. See Show Cached Data.

Builder method	Offline
setLimit	Cached
joinedOnly	Cached
setTags	Cached
withTags	Cached
setSearchKeyword	Server only — cached page is empty