Plupload in metabox - AJAX action not working in Class

Question

I'm trying to put the WP Pluploader into a meta box on my posts page - as per Plupload Intergration in a meta-box? and http://www.krishnakantsharma.com/2012/01/image-uploads-on-wordpress-admin-screens-using-jquery-and-new-plupload/

I got it all working as in the example in the second link. However, I want to put it all into a class file. It stops working if I wrap it all into a Class. And it's all because of:

function g_plupload_action()
{ 
    // check ajax noonce
    $imgid = $_POST["imgid"];
    check_ajax_referer($imgid . 'pluploadan');

    // handle file upload
    $status = wp_handle_upload($_FILES[$imgid . 'async-upload'], array('test_form' => true, 'action' => 'plupload_action'));

    // send the uploaded file url in response
    echo $status['url'];
    exit;
}

It works if this function is outside the Class and called through:

add_action('wp_ajax_plupload_action', "g_plupload_action");

But inside the Class and called with:

add_action('wp_ajax_plupload_action', array($this, 'g_plupload_action'));

and the return data is 0.

What do I need to do in function g_plupload_action() to make it work?

Answer 1

Aha, the problem as that I was calling the wp_ajax_plupload_action from within my page conditional check like so:

function __construct()
{
    global $pagenow;

    $pages = array('post.php', 'post-new.php');

    if (in_array($pagenow, $pages)) :

        add_action('add_meta_boxes', array($this, 'dhf_video_meta_box'));
        add_action('admin_print_scripts', array($this, 'video_meta_js'));
        add_action('admin_head', array($this, 'plupload_admin_head'));
        add_action('admin_print_scripts', array($this, 'video_meta_css'));
        add_action('wp_ajax_plupload_action', array($this, 'plupload_action'));

    endif;
}

You don't want to do it like that. Take the add_action('wp_ajax_plupload_action', array($this, 'plupload_action')); outside of that check and everything works again.