add_jetPack_slideshow.php

<?php 

/**
 * Slideshow shortcode usage: [gallery type="slideshow"] or the older [slideshow]
 */
if(!class_exists('zl_add_jetPack_slideshow')){
  class zl_add_jetPack_slideshow {
    public $instance_count = 0;

    function __construct() {
      global $shortcode_tags;

      $needs_scripts = false;

            // Only if the slideshow shortcode has not already been defined.
      if ( ! array_key_exists( 'slideshow', $shortcode_tags ) ) {
        add_shortcode( 'slideshow', array( $this, 'shortcode_callback' ) );
        $needs_scripts = true;
      }

            // Only if the gallery shortcode has not been redefined.
      if ( isset( $shortcode_tags['gallery'] ) && $shortcode_tags['gallery'] == 'gallery_shortcode' ) {
        add_filter( 'post_gallery', array( $this, 'post_gallery' ), 1002, 2 );
        add_filter( 'jetpack_gallery_types', array( $this, 'add_gallery_type' ), 10 );
        $needs_scripts = false;
      }
    }

        /**
         * Responds to the [gallery] shortcode, but not an actual shortcode callback.
         *
         * @param $value An empty string if nothing has modified the gallery output, the output html otherwise
         * @param $attr The shortcode attributes array
         *
         * @return string The (un)modified $value
         */
        function post_gallery( $value, $attr ) {
            // Bail if somebody else has done something
          if ( ! empty( $value ) )
            return $value;

            // If [gallery type="slideshow"] have it behave just like [slideshow]
          if ( ! empty( $attr['type'] ) && 'slideshow' == $attr['type'] )
            return $this->shortcode_callback( $attr );

          return $value;
        }

        /**
         * Add the Slideshow type to gallery settings
         *
         * @param $types An array of types where the key is the value, and the value is the caption.
         * @see Jetpack_Tiled_Gallery::media_ui_print_templates
         */
        function add_gallery_type( $types = array() ) {
          $types['slideshow'] = esc_html__( 'Slideshow', 'jetpack' );
          return $types;
        }

        function settings_select( $name, $values, $extra_text = '' ) {
          if ( empty( $name ) || empty( $values ) || ! is_array( $values ) ) {
            return;
          }
          $option = get_option( $name );
          ?>
          <fieldset>
            <select name="<?php echo esc_attr( $name ); ?>" id="<?php esc_attr( $name ); ?>">
              <?php foreach ( $values as $key => $value ) : ?>
                <option value="<?php echo esc_attr( $key ); ?>" <?php selected( $key, $option ); ?>>
                  <?php echo esc_html( $value ); ?>
                </option>
              <?php endforeach; ?>
            </select>
            <?php if ( ! empty( $extra_text ) ) : ?>
              <p class="description"><?php echo esc_html( $extra_text ); ?></p>
            <?php endif; ?>
          </fieldset>
          <?php
        }

        function shortcode_callback( $attr, $content = null ) {
          global $post, $content_width;

          $attr = shortcode_atts( array(
            'trans'     => 'slide',
            'order'     => 'ASC',
            'orderby'   => 'menu_order ID',
            'id'        => $post->ID,
            'include'   => '',
            'exclude'   => '',
            ), $attr );

          if ( 'rand' == strtolower( $attr['order'] ) )
            $attr['orderby'] = 'none';

          $attr['orderby'] = sanitize_sql_orderby( $attr['orderby'] );
          if ( ! $attr['orderby'] )
            $attr['orderby'] = 'menu_order ID';

            // Don't restrict to the current post if include
          $post_parent = ( empty( $attr['include'] ) ) ? intval( $attr['id'] ) : null;

          $attachments = get_posts( array(
            'post_status'    => 'inherit',
            'post_type'      => 'attachment',
            'post_mime_type' => 'image',
            'posts_per_page' => -1,
            'post_parent'    => $post_parent,
            'order'          => $attr['order'],
            'orderby'        => $attr['orderby'],
            'include'        => $attr['include'],
            'exclude'        => $attr['exclude'],
            ) );

          if ( count( $attachments ) < 2 )
            return;

          $gallery_instance = sprintf( "gallery-%d-%d", $attr['id'], ++$this->instance_count );

          $gallery = array();
          foreach ( $attachments as $attachment ) {
            $attachment_image_src = wp_get_attachment_image_src( $attachment->ID, 'full' );
                $attachment_image_src = $attachment_image_src[0]; // [url, width, height]
                $caption = apply_filters( 'jetpack_slideshow_slide_caption', wptexturize( strip_tags( $attachment->post_excerpt ) ), $attachment->ID );

                $gallery[] = (object) array(
                  'src'     => (string) esc_url_raw( $attachment_image_src ),
                  'id'      => (string) $attachment->ID,
                  'caption' => (string) $caption,
                  );
              }

              $max_width = intval( get_option( 'large_size_w' ) );
              $max_height = 450;
              if ( intval( $content_width ) > 0 )
                $max_width = min( intval( $content_width ), $max_width );

              $color = Jetpack_Options::get_option( 'slideshow_background_color', 'black' );

              $js_attr = array(
                'gallery'  => $gallery,
                'selector' => $gallery_instance,
                'width'    => $max_width,
                'height'   => $max_height,
                'trans'    => $attr['trans'] ? $attr['trans'] : 'slide',
                'color'    => $color,
                );

            // Show a link to the gallery in feeds.
              if ( is_feed() )
                return sprintf( '<a href="%s">%s</a>',
                  esc_url( get_permalink( $post->ID ) . '#' . $gallery_instance . '-slideshow' ),
                  esc_html__( 'Click to view slideshow.', 'jetpack' )
                  );

              return $this->slideshow_js( $js_attr );
            }

        /**
         * Render the slideshow js
         *
         * Returns the necessary markup and js to fire a slideshow.
         *
         * @uses $this->enqueue_scripts()
         */
        function slideshow_js( $attr ) {
          

          $output = '';

            //$output .= '<p class="jetpack-slideshow-noscript robots-nocontent">' . esc_html__( 'This slideshow requires JavaScript.', 'jetpack' ) . '</p>';
          ob_start();
          $items = $attr['gallery'];
                /*echo '<pre>'; 
                print_r($items);
                echo '</pre>';*/
                if($items){
                  echo '<div class="owl-carousel post-gallery">';
                  foreach ($items as $item) {
                    $item_id = $caption = '';

                    $item_id =  $item->id;
                    $caption =  $item->caption;

                    $image_size = 'post_thumb';
                    $rawurl = wp_get_attachment_image_src( $item_id, $image_size );
                    $linkto = wp_get_attachment_url( $item_id ); 
                    $image_url = $rawurl[0];

                    echo '<div>';
                    echo '<a href="'.$linkto.'">';
                    echo '<img src="'.$image_url.'" alt="" />';
                    echo '</a>';
                    if($caption){
                      echo '<div class="zl_post_gallery_caption">'.$caption.'</div>';
                    }
                    echo '</div>';
                  }
                  echo '</div>';
                }
                $output .= ob_get_clean();
                $output .= '';
                

                return $output;
              }

              

        /**
         * Actually enqueues the scripts and styles.
         */
        function enqueue_scripts() {
          static $enqueued = false;

          if ( $enqueued )
            return;

            //wp_enqueue_script( $handle, $src, $deps, $ver, $in_footer );

          $enqueued = true;
        }

        public static function init() {
          $gallery = new zl_add_jetPack_slideshow;
        }
      }
    }
    add_action( 'init', array( 'zl_add_jetPack_slideshow', 'init' ) );

    ?>