Custom bulk action for media gallery items

I’m trying to add custom “Bulk Actions” to WP 3.5 new media gallery items.
I started from this excellent tutorial which does exactly what I need, but with regular posts; so i tried to adapt it to work with media gallery items.

Starting from the original plugin code, here’s what I came up until now (in my functions.php):

/*
Plugin Name: Custom Bulk Action Demo
Plugin URI: http://www.foxrunsoftware.net/articles/wordpress/add-custom-bulk-action/
Description: A working demonstration of a custom bulk action
Author: Justin Stern
Author URI: http://www.foxrunsoftware.net
Version: 0.1

    Copyright: © 2012 Justin Stern (email : justin@foxrunsoftware.net)
    License: GNU General Public License v3.0
    License URI: http://www.gnu.org/licenses/gpl-3.0.html
*/

    if(is_admin()) {
        // admin actions/filters
        add_action('admin_footer', 'custom_bulk_admin_footer');
        add_action('load-upload.php', 'custom_bulk_action');
        add_action('admin_notices', 'custom_bulk_admin_notices');
    }

/**
 * Step 1: add the custom Bulk Action to the select menus
 */
function custom_bulk_admin_footer() {
    global $pagenow;

    if($pagenow == 'upload.php') {
        ?>
            <script type="text/javascript">
                jQuery(document).ready(function() {
                    jQuery('<option>').val('appr_1').text('<?php _e('Approva per album privato')?>').appendTo("select[name="action"]");                        
                    jQuery('<option>').val('appr_1').text('<?php _e('Approva per album privato')?>').appendTo("select[name="action2"]");
                });
            </script>
        <?php
    }
}


/**
 * Step 2: handle the custom Bulk Action
 * 
 * Based on the post http://wordpress.stackexchange.com/questions/29822/custom-bulk-action
 */
function custom_bulk_action() {
    global $typenow,$pagenow;
    $post_type = $typenow;

    //if($post_type == 'post') {
    if($pagenow == 'upload.php') {

        // get the action
        $wp_list_table = _get_list_table('WP_Media_List_Table');  // depending on your resource type this could be WP_Users_List_Table, WP_Comments_List_Table, etc
        $action = $wp_list_table->current_action();

        $allowed_actions = array("appr_1","appr_2");
        if(!in_array($action, $allowed_actions)) return;

        // security check
        check_admin_referer('bulk-posts');

        // make sure ids are submitted.  depending on the resource type, this may be 'media' or 'ids'
        if(isset($_REQUEST['post'])) {
            $post_ids = array_map('intval', $_REQUEST['post']);
        }

        if(empty($post_ids)) return;

        // this is based on wp-admin/edit.php
        $sendback = remove_query_arg( array('exported', 'untrashed', 'deleted', 'ids'), wp_get_referer() );
        if ( ! $sendback )
            //$sendback = admin_url( "edit.php?post_type=$post_type" );
            $sendback = admin_url( "post.php" );

        $pagenum = $wp_list_table->get_pagenum();
        $sendback = add_query_arg( 'paged', $pagenum, $sendback );

        switch($action) {
            case 'appr_1':

                // if we set up user permissions/capabilities, the code might look like:
                //if ( !current_user_can($post_type_object->cap->export_post, $post_id) )
                //  wp_die( __('You are not allowed to export this post.') );

                $exported = 0;
                foreach( $post_ids as $post_id ) {

                    if ( !$this->perform_export($post_id) )
                        wp_die( __('Error exporting post.') );

                    $exported++;
                }

                $sendback = add_query_arg( array('exported' => $exported, 'ids' => join(',', $post_ids) ), $sendback );
            break;

            default: return;
        }

        $sendback = remove_query_arg( array('action', 'action2', 'tags_input', 'post_author', 'comment_status', 'ping_status', '_status',  'post', 'bulk_edit', 'post_view'), $sendback );

        wp_redirect($sendback);
        exit();
    }
}


/**
 * Step 3: display an admin notice on the Posts page after exporting
 */
function custom_bulk_admin_notices() {
    global $post_type, $pagenow;

    if($pagenow == 'upload.php' && isset($_REQUEST['exported']) && (int) $_REQUEST['exported']) {
        $message = sprintf( _n( 'Post exported.', '%s posts exported.', $_REQUEST['exported'] ), number_format_i18n( $_REQUEST['exported'] ) );
        echo "<div class=\"updated\"><p>{$message}</p></div>";
    }
}

function perform_export($post_id) {
    // do something
    return true;
}

The code should do nothing (see perform_export() function) and return a “Post exported” message, but is not working.
The new bulk actions correctly displays, but I get a security error (“Are you sure you want to do this?”). And if I disable the security check

check_admin_referer('bulk-posts');

I don’t see the confirmation message.

I think that my problems could be in this hook I’m using (I’m quite a noob in hooks handling!!)

add_action('load-upload.php', 'custom_bulk_action');

and in the $sendback variable which holds the page that handles the actual work:

$sendback = admin_url( "post.php" );

Can you help me firguring out which hooks and sendback page should I use?
Thanks 🙂

I had a very similar question (“How to make custom bulk actions work on the media/upload page?”) about Justin Stern’s Custom Bulk Action Demo, which was just answered.

My biggest piece of advice to you is to take the adaptation one step at a time: make sure you have export working for media before anything else. Don’t try to do two steps at once. (That’s the secret to all this computer stuff: break things into small, manageable pieces.)

For your specific questions at the end:

• Replacing check_admin_referer('bulk-posts') with check_admin_referer('bulk-media') will get rid of “Are you sure you want to do this?”.
• The hook add_action('load-upload.php', 'custom_bulk_action') may sound silly, but is fine.
• $sendback = admin_url( "upload.php" ) is fine.

In part 1, custom_bulk_admin_footer(), and part 3, custom_bulk_admin_notices(), you want to replace

• 'post' –> 'attachment'.

Elsewhere you need to replace

• post.php –> upload.php,
• edit –> upload, and
• post –> media.

Part 2, custom_bulk_action(), requires more-complicated adaptations. I recommend you use the code below (from the question linked above).

 add_action('load-upload.php', array(&$this, 'custom_bulk_action'));


function custom_bulk_action() {

//  ***if($post_type == 'attachment') {  REPLACE WITH:
    if ( !isset( $_REQUEST['detached'] ) ) {

    // get the action
    $wp_list_table = _get_list_table('WP_Media_List_Table');  
    $action = $wp_list_table->current_action();

    echo "\naction = $action\n</pre>";

    $allowed_actions = array("export");
    if(!in_array($action, $allowed_actions)) return;

    // security check
//  ***check_admin_referer('bulk-posts'); REPLACE WITH:
    check_admin_referer('bulk-media'); 

    // make sure ids are submitted.  depending on the resource type, this may be 'media' or 'ids'
    if(isset($_REQUEST['media'])) {
      $post_ids = array_map('intval', $_REQUEST['media']);
    }

    if(empty($post_ids)) return;

    // this is based on wp-admin/edit.php
    $sendback = remove_query_arg( array('exported', 'untrashed', 'deleted', 'ids'), wp_get_referer() );
    if ( ! $sendback )
      $sendback = admin_url( "upload.php?post_type=$post_type" );

    $pagenum = $wp_list_table->get_pagenum();
    $sendback = add_query_arg( 'paged', $pagenum, $sendback );

    switch($action) {
      case 'export':

        // if we set up user permissions/capabilities, the code might look like:
        //if ( !current_user_can($post_type_object->cap->export_post, $post_id) )
        //  wp_die( __('You are not allowed to export this post.') );

        $exported = 0;
        foreach( $post_ids as $post_id ) {

          if ( !$this->perform_export($post_id) )
            wp_die( __('Error exporting post.') );
          $exported++;
        }

        $sendback = add_query_arg( array('exported' => $exported, 'ids' => join(',', $post_ids) ), $sendback );
      break;

      default: return;
    }

    $sendback = remove_query_arg( array('action', 'action2', 'tags_input', 'post_author', 'comment_status', 'ping_status', '_status',  'post', 'bulk_edit', 'post_view'), $sendback );

    wp_redirect($sendback);
    exit();
  }
}