bp_activity_admin_reply()

function bp_activity_admin_reply() {
	// Check nonce.
	check_ajax_referer( 'bp-activity-admin-reply', '_ajax_nonce-bp-activity-admin-reply' );

	$parent_id = ! empty( $_REQUEST['parent_id'] ) ? (int) $_REQUEST['parent_id'] : 0;
	$root_id   = ! empty( $_REQUEST['root_id'] )   ? (int) $_REQUEST['root_id']   : 0;

	// $parent_id is required
	if ( empty( $parent_id ) )
		die( '-1' );

	// If $root_id not set (e.g. for root items), use $parent_id.
	if ( empty( $root_id ) )
		$root_id = $parent_id;

	// Check that a reply has been entered.
	if ( empty( $_REQUEST['content'] ) )
		die( __( 'ERROR: Please type a reply.', 'buddyboss' ) );

	// Check parent activity exists.
	$parent_activity = new BP_Activity_Activity( $parent_id );
	if ( empty( $parent_activity->component ) )
		die( __( 'ERROR: The item you are trying to reply to cannot be found, or it has been deleted.', 'buddyboss' ) );

	// @todo: Check if user is allowed to create new activity items
	// if ( ! current_user_can( 'bp_new_activity' ) )
	if ( ! bp_current_user_can( 'bp_moderate' ) )
		die( '-1' );

	// Add new activity comment.
	$new_activity_id = bp_activity_new_comment( array(
		'activity_id' => $root_id,              // ID of the root activity item.
		'content'     => $_REQUEST['content'],
		'parent_id'   => $parent_id,            // ID of a parent comment.
	) );

	// Fetch the new activity item, as we need it to create table markup to return.
	$new_activity = new BP_Activity_Activity( $new_activity_id );

	// This needs to be set for the BP_Activity_List_Table constructor to work.
	set_current_screen( 'toplevel_page_bp-activity' );

	// Set up an output buffer.
	ob_start();
	$list_table = new BP_Activity_List_Table();
	$list_table->single_row( (array) $new_activity );

	// Get table markup.
	$response =  array(
		'data'     => ob_get_contents(),
		'id'       => $new_activity_id,
		'position' => -1,
		'what'     => 'bp_activity',
	);
	ob_end_clean();

	// Send response.
	$r = new WP_Ajax_Response();
	$r->add( $response );
	$r->send();

	exit();
}