/**
  * the_content filter that will add linked posts to the bottom of the main post content
  *
  * @param $content
  *
  * @return string
  */
 public function run($content)
 {
     /**
      * Wow, what's going on here?! Well, setup_postdata() sets a lot of variables but does not change the $post variable.
      * All checks return the main queried ID but we want to check if this specific filter call is the for the 'main' content.
      * The method setup_postdata() does global and set the $id variable, so we're checking that.
      */
     global $id;
     // Only run on single
     if (!is_singular() || !is_main_query() || $id != get_queried_object_id()) {
         return $content;
     }
     $ptl_manager = new SP_Connection_Manager();
     // Add a meta query so we only get relations that have the PM_PTL_APDC or PM_PTL_APDP set to true (1)
     $args = array('meta_query' => array(array('key' => SP_Constants::PM_PTL_APDC, 'value' => '1')));
     // Get the connections
     $relations = $ptl_manager->get_connections($args);
     // Check relations
     if (count($relations) > 0) {
         // Post Link Manager
         $pl_manager = new SP_Post_Link_Manager();
         // Current post ID
         $post_id = get_the_ID();
         // Loop relations
         foreach ($relations as $relation) {
             // Check if this relation allows children links to show
             if ('1' === $relation->get_after_post_display_children()) {
                 $children_relations[] = $relation;
             }
         }
         // Opening the wrapper div
         $content .= "<div class='pc-post-children'>\n";
         foreach ($relations as $relation) {
             // Get the linked posts
             $pc_posts = $pl_manager->get_children($relation->get_slug(), $post_id);
             if (count($pc_posts) > 0) {
                 $content .= $this->create_post_list($relation->get_slug(), $relation->get_title(), $pc_posts);
             }
         }
         // Close the wrapper div
         $content .= "</div>\n";
     }
     return $content;
 }
 /**
  * Metabox content
  *
  * @access public
  * @return void
  */
 public function callback($post)
 {
     echo "<div class='sp_mb_manage'>\n";
     // Add nonce
     echo "<input type='hidden' name='sp-ajax-nonce' id='sp-ajax-nonce' value='" . wp_create_nonce('post-connector-ajax-nonce-omgrandomword') . "' />\n";
     // Output plugin URL in hidden val
     echo "<input type='hidden' name='sp-dir-img' id='sp-dir-img' value='" . plugins_url('/core/assets/images/', Post_Connector::get_plugin_file()) . "' />\n";
     // Setup vars
     $sp_parent = isset($_GET['sp_parent']) ? $_GET['sp_parent'] : '';
     $sp_pt_link = isset($_GET['sp_pt_link']) ? $_GET['sp_pt_link'] : '';
     // Create a Post Link Manager object
     $post_link_manager = new SP_Post_Link_Manager();
     // Get the children
     $children = $post_link_manager->get_children($this->connection->get_slug(), $post->ID);
     $child_post_type = get_post_type_object($this->connection->get_child());
     echo "<div class='pt_button_holder'>\n";
     // Check if user is allowed to add new children
     if ($this->connection->get_add_new() == '1') {
         // Build the Post Connector link existing post URL
         $url = get_admin_url() . "post-new.php?post_type=" . $this->connection->get_child() . "&amp;sp_parent=" . SP_Parent_Param::generate_sp_parent_param($post->ID, $sp_pt_link, $sp_parent, 0) . "&amp;sp_pt_link=" . $this->connection->get_id();
         // WPML check
         if (isset($_GET['lang'])) {
             $url .= "&lang=" . $_GET['lang'];
         }
         echo "<span id='view-post-btn'>";
         echo "<a href='" . $url . "' class='button'>";
         printf(__('Add new %s', 'post-connector'), $child_post_type->labels->singular_name);
         echo "</a>";
         echo "</span>\n";
     }
     // Check if user is allowed to add existing children
     if ($this->connection->get_add_existing() == '1') {
         // Build the Post Connector link existing post URL
         $url = get_admin_url() . "admin.php?page=link_post_screen&amp;sp_parent=" . SP_Parent_Param::generate_sp_parent_param($post->ID, $sp_pt_link, $sp_parent, 0) . "&amp;sp_pt_link=" . $this->connection->get_id();
         // WPML check
         if (isset($_GET['lang'])) {
             $url .= "&amp;lang=" . $_GET['lang'];
         }
         /**
          * Action: 'pc_meta_box_manage_add_existing_url' - Allow adjusting of 'add existing' URL
          *
          * @api string $url The URL
          * @param SP_Connection $connection The connection
          */
         $url = apply_filters('pc_meta_box_manage_add_existing_url', $url, $this->connection);
         echo "<span id='view-post-btn'>";
         echo "<a href='" . $url . "' class='button'>";
         printf(__('Add existing %s', 'post-connector'), $child_post_type->labels->singular_name);
         echo "</a>";
         echo "</span>\n";
     }
     echo "</div>\n";
     if (count($children) > 0) {
         $table_classes = 'wp-list-table widefat fixed pages pt_table_manage';
         /**
          * Action: 'pc_meta_box_manage_table_classes' - Allow adjusting meta box manage table classes
          *
          * @api string $table_classes The table classes
          * @param SP_Connection $connection The connection
          */
         $table_classes = apply_filters('pc_meta_box_manage_table_classes', $table_classes, $this->connection);
         // Managet table
         echo "<table class='" . $table_classes . "'>\n";
         echo "<tbody>\n";
         $i = 0;
         foreach ($children as $link_id => $child) {
             $child_id = $child->ID;
             $edit_url = get_admin_url() . "post.php?post={$child_id}&amp;action=edit&amp;sp_parent=" . SP_Parent_Param::generate_sp_parent_param($post->ID, $sp_pt_link, $sp_parent, 0) . "&sp_pt_link=" . $this->connection->get_id();
             echo "<tr id='{$link_id}'>\n";
             echo "<td>";
             echo "<strong><a href='{$edit_url}' class='row-title' title='{$child->post_title}'>{$child->post_title}</a></strong>\n";
             echo "<div class='row-actions'>\n";
             echo "<span class='edit'><a href='{$edit_url}' title='" . __('Edit this item', 'post-connector') . "'>";
             _e('Edit', 'post-connector');
             echo "</a> | </span>";
             echo "<span class='trash'><a class='submitdelete' title='" . __('Delete this item', 'post-connector') . "' href='javascript:;'>";
             _e('Delete', 'post-connector');
             echo "</a></span>";
             echo "</div>\n";
             echo "</td>\n";
             echo "</tr>\n";
             $i++;
         }
         echo "</tbody>\n";
         echo "</table>\n";
     } else {
         echo '<br/>';
         printf(__('No %s found.', 'post-connector'), $child_post_type->labels->name);
     }
     // Reset Post Data
     wp_reset_postdata();
     echo "</div>\n";
 }