Block Users

Learn how to block and unblock users in your Flutter app using the CometChat SDK to manage user interactions and privacy.

AI Integration Quick Reference

// Block users
List<String> uids = ["UID1", "UID2"];
CometChat.blockUser(uids, onSuccess: (Map<String, dynamic> map) {
  debugPrint("Blocked: $map");
}, onError: (CometChatException e) {
  debugPrint("Error: ${e.message}");
});

// Unblock users
CometChat.unblockUser(uids, onSuccess: (Map<String, dynamic> map) {
  debugPrint("Unblocked: $map");
}, onError: (CometChatException e) {
  debugPrint("Error: ${e.message}");
});

// Get blocked users list
BlockedUsersRequest request = (BlockedUsersRequestBuilder()..limit = 30).build();
request.fetchNext(onSuccess: (List<User> users) { }, onError: (e) { });

Directions: directionBlockedByMe | directionHasBlockedMe | directionBoth (default)

Block users to prevent them from sending messages to the logged-in user. This feature helps users manage their privacy and control who can communicate with them.

Available via: SDK | REST API | UI Kits

Block Users

In other words, as a logged-in user, how do I block a user from sending me messages?

You can block users using the blockUser() method. Once any user is blocked, all the communication to and from the respective user will be completely blocked. You can block multiple users in a single operation. The blockUser() method takes a List<String> as a parameter which holds the list of UIDs to be blocked.

Parameters

Parameter	Type	Description
uids	List<String>?	List of UIDs of users to block
onSuccess	Function(Map<String, dynamic> map)?	Callback triggered on successful block operation
onError	Function(CometChatException excep)?	Callback triggered on error

Dart

List<String > uids = [];
uids.add("UID1");
uids.add("UID2");
uids.add("UID3");
CometChat.blockUser(uids, onSuccess: (Map<String, dynamic> map) {
debugPrint("Blocked User Successfully $map ");
}, onError: (CometChatException e) {
debugPrint("Blocked User Unsuccessful ${e.message} ");
});

Response

On Success — A Map<String, dynamic> containing UIDs as keys and "success" or "fail" as values indicating the result of each block operation:

Map Object:

Parameter	Type	Description	Sample Value
UID1	string	Block result for UID1	"success"
UID2	string	Block result for UID2	"success"
UID3	string	Block result for UID3	"success"

Error

Parameter	Type	Description	Sample Value
code	string	Error code identifier	"ERR_UID_NOT_FOUND"
message	string	Human-readable error message	"The specified UID does not exist."
details	string	Additional technical details	"Please verify the UID and try again."

In the onSuccess() callback, you receive a Map which contains UIDs as the keys and success or fail as the value based on if the block operation for the UID was successful or not.

Unblock Users

In other words, as a logged-in user, how do I unblock a user I previously blocked?

You can unblock the already blocked users using the unblockUser() method. You can unblock multiple users in a single operation. The unblockUser() method takes a List<String> as a parameter which holds the list of UIDs to be unblocked.

Parameters

Parameter	Type	Description
uids	List<String>?	List of UIDs of users to unblock
onSuccess	Function(Map<String, dynamic> map)?	Callback triggered on successful unblock operation
onError	Function(CometChatException excep)?	Callback triggered on error

Dart

List<String > uids = [];
uids.add("UID1");
uids.add("UID2");
uids.add("UID3");

CometChat.unblockUser(uids, onSuccess: (Map<String, dynamic> map) {
 debugPrint("Blocked User Successfully $map ");
 }, onError: (CometChatException e) {
 debugPrint("Blocked User Unsuccessful ${e.message} ");
 });

Response

On Success — A Map<String, dynamic> containing UIDs as keys and "success" or "fail" as values indicating the result of each unblock operation:

Map Object:

Parameter	Type	Description	Sample Value
UID1	string	Unblock result for UID1	"success"
UID2	string	Unblock result for UID2	"success"
UID3	string	Unblock result for UID3	"success"

Error

Parameter	Type	Description	Sample Value
code	string	Error code identifier	"ERR_UID_NOT_FOUND"
message	string	Human-readable error message	"The specified UID does not exist."
details	string	Additional technical details	"Please verify the UID and try again."

In the onSuccess() callback, you receive a Map which contains UIDs as the keys and success or fail as the value based on if the unblock operation for the UID was successful or not.

Get list of blocked users

In other words, as a logged-in user, how do I get a list of all users I’ve blocked?

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

The BlockedUsersRequestBuilder class allows you to set the below parameters:

BlockedUsersRequestBuilder

Parameter	Type	Description
limit	int?	Number of blocked users to fetch per request. Max: 100, Default: 30
searchKeyword	String?	Keyword to filter blocked users by name
direction	String?	Direction of block — directionBlockedByMe, directionHasBlockedMe, or directionBoth (default)
setPage	int?	Fetch blocked users from a particular page

Set Limit

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

Dart

BlockedUsersRequest blockedUsersRequest =   (BlockedUsersRequestBuilder()
  ..limit = 50
  ).build();

Set Search Keyword

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

Dart

BlockedUsersRequest blockedUsersRequest =  (BlockedUsersRequestBuilder()
  ..limit = 50
  ..searchKeyword = "abc"
  ).build();

Set Direction

• CometChatBlockedUsersDirection.directionBlockedByMe - This will ensure that the list of blocked users only contains the users blocked by the logged in user.
• CometChatBlockedUsersDirection.directionHasBlockedMe - This will ensure that the list of blocked users only contains the users that have blocked the logged in user.
• CometChatBlockedUsersDirection.directionBoth - This will make sure the list of users includes both the above cases. This is the default value for the direction variable if it is not set.

Dart

BlockedUsersRequest blockedUsersRequest = (BlockedUsersRequestBuilder()
  ..limit = 50
  ..direction = CometChatBlockedUsersDirection.directionBlockedByMe
  ).build();  

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

Once you have the object of the BlockedUsersRequest class, you need to call the fetchNext() method. Calling this method will return a list of User objects containing n number of blocked users where N is the limit set in the builder class.

Dart

BlockedUsersRequest blockedUsersRequest = (BlockedUsersRequestBuilder()
    ..limit = 30
  ).build();

blockedUsersRequest.fetchNext(onSuccess: (List<User> userList){
    debugPrint("Custom Message Sent Successfully : $userList ");
  }, onError: (CometChatException e){
    debugPrint("Blocked User Request failed with exception: ${e.message}");
}); 

Response

On Success — A List<User> containing the blocked users:

User Object (per item in list):

Parameter	Type	Description	Sample Value
uid	string	Unique identifier of the user	"cometchat-uid-3"
name	string	Display name of the user	"Kevin Hart"
link	string	Profile link	null
avatar	string	Avatar URL	"https://assets.cometchat.io/sampleapp/v2/users/cometchat-uid-3.webp"
metadata	object	Custom metadata	{}
status	string	Online status	"offline"
role	string	User role	"default"
statusMessage	string	Status message	null
tags	array	User tags	[]
hasBlockedMe	boolean	Whether this user has blocked the current user	false
blockedByMe	boolean	Whether the current user has blocked this user	true
lastActiveAt	number	Epoch timestamp of last activity	1745550000

Error

Parameter	Type	Description	Sample Value
code	string	Error code identifier	"ERR_UID_NOT_FOUND"
message	string	Human-readable error message	"The specified UID does not exist."
details	string	Additional technical details	"Please verify the UID and try again."

Relevant fields to access on returned User objects:

Field	Type	Description
blockedByMe	bool	Whether the logged-in user has blocked this user
hasBlockedMe	bool	Whether this user has blocked the logged-in user

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Next Steps

Retrieve Users

Fetch and filter users from your CometChat app

User Management

Create, update, and delete users programmatically

User Presence

Track online/offline status of users in real-time

Users Overview

Complete guide to user features in CometChat