How to extend LINK TO functionality in ATTACHMENT DISPLAY SETTINGS

Question

In WP 3.4.x and earlier, it was possible to add a button to the media manager by messing around in an attachment_fields_to_edit filter. For example, a plugin could, when it figured out that an item was an audio file, append some HTML for an extra button to the url field, like so.

 $playertag = "[audio $url]";
 $fields['url']['html'] .= 
      "<button type='button' class='button data-link-url='$playertag' urlaudioplayer audio-player-$postid'>Audio Player</button>"; 

The new media manager has changed the set of buttons that were in that html tag into a pulldown menu -- a <select .../> item. The html code is emitted in media-template.php. The new code still calls attachment_fields_to_edit filters, but doesn't pass in any fields.

Is there a way to extend this select item without hacking the core (which I won't do). Is it conceivable to write a bit of js which will use jQuery to add an item to it?

Answer 1

Yes, it's possible in the same manner as before. I don't know why you think the filter is not passing the parameters anymore.

add_filter('attachment_fields_to_edit', 'user16975_edit_fields', 10, 2);
function user16975_edit_fields($form_fields, $attachment){

    // check for an audio attachment
    if ( substr($attachment->post_mime_type, 0, 5) == 'audio' ) {
        $playertag =  $playertag = "[audio ".wp_get_attachment_url($attachment->ID)."]";
        $form_fields["audioplayer"] = array(
            "label" => "Audio player",
            "input" => "html",
            "html" => "<button type='button' class='button' data-link-url='$playertag' audioplayer='audio-player-{$attachment->ID}'>Audio Player</button>",
        );
    }

    return $form_fields;
}

Here is the result :