function bp_legacy_theme_activity_template_loader() {
	if ( ! bp_is_post_request() ) {
		return;
	}

	$scope = '';
	if ( ! empty( $_POST['scope'] ) )
		$scope = $_POST['scope'];

	// We need to calculate and return the feed URL for each scope.
	switch ( $scope ) {
		case 'friends':
			$feed_url = bp_loggedin_user_domain() . bp_get_activity_slug() . '/friends/feed/';
			break;
		case 'groups':
			$feed_url = bp_loggedin_user_domain() . bp_get_activity_slug() . '/groups/feed/';
			break;
		case 'favorites':
			$feed_url = bp_loggedin_user_domain() . bp_get_activity_slug() . '/favorites/feed/';
			break;
		case 'mentions':
			$feed_url = bp_loggedin_user_domain() . bp_get_activity_slug() . '/mentions/feed/';

			if ( isset( $_POST['_wpnonce_activity_filter'] ) && wp_verify_nonce( wp_unslash( $_POST['_wpnonce_activity_filter'] ), 'activity_filter' ) ) {
				bp_activity_clear_new_mentions( bp_loggedin_user_id() );
			}

			break;
		default:
			$feed_url = home_url( bp_get_activity_root_slug() . '/feed/' );
			break;
	}

	// Buffer the loop in the template to a var for JS to spit out.
	ob_start();
	bp_get_template_part( 'activity/activity-loop' );
	$result['contents'] = ob_get_contents();

	/**
	 * Filters the feed URL for when activity is requested via AJAX.
	 *
	 * @since 1.7.0
	 *
	 * @param string $feed_url URL for the feed to be used.
	 * @param string $scope    Scope for the activity request.
	 */
	$result['feed_url'] = apply_filters( 'bp_legacy_theme_activity_feed_url', $feed_url, $scope );
	ob_end_clean();

	exit( json_encode( $result ) );
}