BuddyPress.org

Yeah, Favorites is more of a personal bookmarking sort of feature. I believe there are plugins available that will replicate the Facebook “Like” functionality, although I haven’t used any of them myself.

I know this is a very old thread, but here’s some useful code for solving this problem (put it in functions.php) in case someone else stumbles upon it

add_action("bp_activity_add_user_favorite","favorite_notification", 10, 2);

function favorite_notification( $activity_id, $user_id = 0){

	$activities = bp_activity_get_specific( array( 'activity_ids' => $activity_id) );

	bp_core_add_notification( $activity_id, $activities["activities"][0]->user_id, "notifier", "<a href='".get_site_url()."/activity/p/$activity_id'>New Like!</a>" ) ;
}

this code work for me but java script not work and when user favorite comment user can’t remove notification help me

define("BP_FAVORITE_NOTIFIER_SLUG","fa_notification");

    function bp_favorite_setup_globals() {	
	global $bp, $current_blog;
    $bp->bp_favorite=new stdClass();
    $bp->bp_favorite->id = 'bp_favorite';
    $bp->bp_favorite->slug = BP_FAVORITE_NOTIFIER_SLUG;
    $bp->bp_favorite->notification_callback = 'bp_favorite_format_notifications';//show the notification   
    $bp->active_components[$bp->bp_favorite->id] = $bp->bp_favorite->id;
			
            do_action( 'bp_favorite_setup_globals' );
    }
            add_action( 'bp_setup_globals', 'bp_favorite_setup_globals' );
     

function bp_favorite_format_notifications(  $action, $activity_id, $secondary_item_id, $total_items,$format='string'  ) { 
$action_checker = explode('_', $action);
$activities = bp_activity_get_specific( array( 'activity_ids' => $activity_id, 'display_comments' => true) );
	$glue = '';
	$user_names = array();

	$users = find_favorite_involved_persons($activity_id, $action);
	$total_user = $count = count($users);

	if($count > 2) {
		$users = array_slice($users, $count - 2);
		$count = $count - 2;
		$glue = ", ";
	} else if($total_user == 2) {
		$glue = " and ";
	}

	foreach((array)$users as $user_id) {
		$user_names[] = bp_core_get_user_displayname($user_id);
	}

	if(!empty($user_names)) {
		$favoriting_users = join($glue, $user_names);
	}

	switch ( $action ) {
		case 'new_bp_favorite_'.$activity_id:
			if($total_user > 2) {
				$text = $favoriting_users.' and '.$count.' liked: '.substr($activities["activities"][0]->content,0,32).'...';
			} else {
				$text = $favoriting_users." like: ".substr($activities["activities"][0]->content,0,32)."...";
			}
		break;
	}
	$url = '<div id="'.$action.'"class="notification"><a href="#" class="social-delete" onclick="deleteAjaxNotification(\''.$action.'\',\''.$activity_id.'\', \''.admin_url( 'admin-ajax.php' ).'\'); return false;">x</a><span class="social-loader"></span></div>';
	$link = favorite_activity_get_permalink( $activity_id );

	if($format=='string') {
		return apply_filters( 'bp_activity_multiple_favorite_notifications', '<a href="' . $link. '">' . $text . '</a>'. $url .'' ,$users, $total_user, $count, $glue, $link );
	} else {
		return array(
			'link' => $link,
			'text' => $text
		);
	}
	return false;

}
function find_favorite_involved_persons($activity_id, $action) {
	global $bp,$wpdb;
	$table = $wpdb->prefix . 'bp_notifications';
	return $wpdb->get_col($wpdb->prepare("select DISTINCT(secondary_item_id) from {$table} where item_id=%d and secondary_item_id!=%d and component_action = %s",$activity_id,$bp->loggedin_user->id, $action));
}
function favorite_activity_get_permalink( $activity_id, $activity_obj = false ) {
	global $bp;

	if ( !$activity_obj )
		$activity_obj = new BP_Activity_Activity( $activity_id );
                    
		if ( 'activity_comment' == $activity_obj->type )
			$link = bp_get_activity_directory_permalink(). 'p/' . $activity_obj->item_id . '/';
		else
			$link = bp_get_activity_directory_permalink() . 'p/' . $activity_obj->id . '/';

	return apply_filters( 'ac_notifier_activity_get_permalink', $link );

}

function favorite_notifier_remove_notification($activity ,$has_access){
       global $bp;
       if($has_access)		       
	   bp_core_delete_notifications_for_user_by_type( $bp->loggedin_user->id, $bp->bp_favorite->id, 'new_bp_favorite_'.$activity->id );
	}
add_action("bp_activity_screen_single_activity_permalink","favorite_notifier_remove_notification", 10,2);

function favorite_notification( $activity_id){  
                   global $bp;                 
	               $activities = bp_activity_get_specific( array( 'activity_ids' => $activity_id, 'display_comments' => true) );
				   $author_id = $activities['activities'][0]->user_id;
                   $user_id =  bp_loggedin_user_id();
	// if favoriting own activity, dont send notification
	if( $user_id == $author_id ) {
		return false;
	}
				   if ( bp_is_active( 'notifications' ) ) {
		bp_notifications_add_notification( array(
			'user_id'           => $author_id,
			'item_id'           => $activity_id,
			'secondary_item_id' => $user_id,
			'component_name'    => $bp->bp_favorite->id,
			'component_action'  => 'new_bp_favorite_'.$activity_id,
			'date_notified'     => bp_core_current_time(),
			'is_new'            => 1,
		) );
	}				
}
add_action("bp_activity_add_user_favorite","favorite_notification", 10, 2);

function deleteAjaxNotification(){
    global $bp;        
    bp_core_delete_notifications_by_item_id ($bp->loggedin_user->id, $bp->bp_favorite->id, 'new_bp_favorite_'.$activity->id);     
    die();        
}	
add_action('wp_ajax_deleteAjaxNotification', 'deleteAjaxNotification' ); 

function bp_like_add_like_action() {
global $bp, $activities_template; 
	 if ( bp_activity_can_favorite() ) : 
		
				$my_fav_count = bp_activity_get_meta( bp_get_activity_comment_id(), 'favorite_count' );
				
				$my_fav_count = "<span>".$my_fav_count."</span>";
				
				$is_favorite = apply_filters( 'bp_get_activity_is_favorite', in_array( bp_get_activity_comment_id(), $activities_template->my_favs ) );
		

			 if ( !$is_favorite ) : ?>

				<a href="<?php echo apply_filters( 'bp_get_activity_favorite_link', wp_nonce_url( home_url( bp_get_activity_root_slug() . '/favorite/' . bp_get_activity_comment_id() . '/' ), 'mark_favorite' ) ); ?>" class="tooltip-trigger fav bp-secondary-action bp-primary-action" title="<?php _e( 'Favorite', 'buddypress' ); ?>" style="position:relative;"><?php _e( 'Favorite', 'buddypress' ); ?><?php echo $my_fav_count; ?></a>

			<?php else : ?>

				<a href="<?php echo apply_filters( 'bp_get_activity_favorite_link', wp_nonce_url( home_url( bp_get_activity_root_slug() . '/favorite/' . bp_get_activity_comment_id() . '/' ), 'mark_favorite' ) ); ?>" class="tooltip-trigger unfav bp-secondary-action bp-primary-action" title="<?php _e( 'Remove Favorite', 'buddypress' ); ?>" style="position:relative;"><?php _e( 'Remove Favorite', 'buddypress' ); ?><?php echo $my_fav_count; ?></a>

			<?php endif; 

		 endif; 
}
add_filter( 'bp_activity_comment_options' , 'bp_like_add_like_action', 1000 );

and java code

function deleteAjaxNotification(action_id, activity_id, adminUrl){
    jQuery('#'+action_id).children(".social-delete").html("");
    jQuery('#'+action_id ).children(".social-loader").show(); 

    jQuery.ajax({
        type: 'post',
        url: adminUrl,
        data: { action: "deleteAjaxNotification", action_id:action_id, activity_id:activity_id },
        success:
        function(data) {
        	jQuery('#'+action_id).parent().hide();
        	
        }
     });  
}