xwp/stream

<?php
/**
 * Processes update calls from the Stream Records page.
 *
 * @package WP_Stream
 */

namespace WP_Stream;

/**
 * Class - Live_Update
 */
class Live_Update {
    /**
     * Holds instance of plugin object
     *
     * @var Plugin
     */
    public $plugin;

    /**
     * User meta key/identifier
     *
     * @var string
     */
    public $user_meta_key = 'stream_live_update_records';

    /**
     * List table object instance
     *
     * @var List_Table
     */
    public $list_table = null;

    /**
     * Class constructor.
     *
     * @param Plugin $plugin Instance of plugin object.
     */
    public function __construct( $plugin ) {
        $this->plugin = $plugin;

        // Heartbeat live update.
        add_filter( 'heartbeat_received', array( $this, 'heartbeat_received' ), 10, 2 );

        // Enable / Disable live update per user.
        add_action( 'wp_ajax_stream_enable_live_update', array( $this, 'enable_live_update' ) );
    }

    /**
     * Ajax function to enable/disable live update
     *
     * @return string Ajax respsonse back in JSON format
     */
    public function enable_live_update() {
        check_ajax_referer( $this->user_meta_key . '_nonce', 'nonce' );

        $input = array(
            'checked'   => FILTER_SANITIZE_FULL_SPECIAL_CHARS,
            'user'      => FILTER_SANITIZE_FULL_SPECIAL_CHARS,
            'heartbeat' => FILTER_SANITIZE_FULL_SPECIAL_CHARS,
        );

        $input = filter_input_array( INPUT_POST, $input );

        if ( false === $input ) {
            wp_send_json_error( 'Error in live update checkbox' );
        }

        $checked = ( 'checked' === $input['checked'] ) ? 'on' : 'off';

        $user = (int) $input['user'];

        if ( 'false' === $input['heartbeat'] ) {
            update_user_meta( $user, $this->user_meta_key, 'off' );

            wp_send_json_error( esc_html__( "Live updates could not be enabled because Heartbeat is not loaded.\n\nYour hosting provider or another plugin may have disabled it for performance reasons.", 'stream' ) );

            return;
        }

        $success = update_user_meta( $user, $this->user_meta_key, $checked );

        if ( $success ) {
            wp_send_json_success( ( 'on' === $checked ) ? 'Live Updates enabled' : 'Live Updates disabled' );
        } else {
            wp_send_json_error( 'Live Updates checkbox error' );
        }
    }

    /**
     * Sends updated actions to the list table view
     *
     * @todo Fix reliability issues with sidebar widgets
     *
     * @uses gather_updated_items
     * @uses generate_row
     *
     * @param array $response Response to heartbeat.
     * @param array $data     Data from heartbeat.
     *
     * @return array Data sent to heartbeat
     */
    public function live_update( $response, $data ) {
        unset( $response );

        if ( ! isset( $data['wp-stream-heartbeat-last-time'] ) ) {
            return array();
        }

        $last_time = $data['wp-stream-heartbeat-last-time'];
        $query     = $data['wp-stream-heartbeat-query'];

        if ( empty( $query ) ) {
            $query = array();
        }

        // Decode the query.
        $query = json_decode( wp_kses_stripslashes( $query ) );

        $updated_items = $this->gather_updated_items( $last_time, (array) $query );

        if ( ! empty( $updated_items ) ) {
            ob_start();

            foreach ( $updated_items as $item ) {
                $this->list_table->single_row( $item );
            }

            $send = ob_get_clean();
        } else {
            $send = '';
        }

        return $send;
    }

    /**
     * Sends Updated Actions to the List Table View
     *
     * @param int   $last_time Timestamp of last update.
     * @param array $args      Query args.
     *
     * @return array Array of recently updated items
     */
    public function gather_updated_items( $last_time, $args = array() ) {
        unset( $args );

        if ( false === $last_time ) {
            return '';
        }

        if ( empty( $this->list_table->items ) ) {
            return '';
        }

        $items = array();

        foreach ( $this->list_table->items as $item ) {
            if ( strtotime( $item->created ) > strtotime( $last_time ) ) {
                $items[] = $item;
            } else {
                break;
            }
        }

        return $items;
    }

    /**
     * Handles live updates for Stream Post List
     *
     * @action heartbeat_received
     *
     * @param array $response Response to be sent to heartbeat tick.
     * @param array $data     Data from heartbeat send.
     *
     * @return array Data sent to heartbeat tick
     */
    public function heartbeat_received( $response, $data ) {
        // Only fire when Stream is requesting a live update.
        if ( ! isset( $data['wp-stream-heartbeat'] ) ) {
            return $response;
        }

        $enable_stream_update = ( 'off' !== get_user_meta( get_current_user_id(), $this->user_meta_key ) );

        // Register list table.
        $this->list_table = new List_Table(
            $this->plugin,
            array(
                'screen' => 'toplevel_page_' . $this->plugin->admin->records_page_slug,
            )
        );
        $this->list_table->prepare_items();

        $total_items = isset( $this->list_table->_pagination_args['total_items'] ) ? $this->list_table->_pagination_args['total_items'] : null;
        $total_pages = isset( $this->list_table->_pagination_args['total_pages'] ) ? $this->list_table->_pagination_args['total_pages'] : null;

        if ( isset( $data['wp-stream-heartbeat'] ) && isset( $total_items ) ) {
            $response['total_items'] = $total_items;
            /* translators: %d: number of items (e.g. "42") */
            $response['total_items_i18n'] = sprintf( _n( '%d item', '%d items', $total_items ), number_format_i18n( $total_items ) );
        }

        if ( isset( $data['wp-stream-heartbeat'] ) && 'live-update' === $data['wp-stream-heartbeat'] && $enable_stream_update ) {

            if ( ! empty( $data['wp-stream-heartbeat'] ) ) {
                if ( isset( $total_pages ) ) {
                    $response['total_pages']      = $total_pages;
                    $response['total_pages_i18n'] = number_format_i18n( $total_pages );

                    $query_args          = json_decode( $data['wp-stream-heartbeat-query'], true );
                    $query_args['paged'] = $total_pages;

                    $response['last_page_link'] = esc_url( add_query_arg( $query_args, admin_url( 'admin.php' ) ) );
                } else {
                    $response['total_pages'] = 0;
                }
            }

            $response['wp-stream-heartbeat'] = $this->live_update( $response, $data );

        } else {
            $response['log'] = 'fail';
        }

        return $response;
    }
}