WP3.5 Custom Media Upload

jQuery(document).ready(function($){

  // Uploading files
  var file_frame;

  $('.upload_attachments_button').on('click', function( event ){

    event.preventDefault();

    // If the media frame already exists, reopen it.
    if ( file_frame ) {
      file_frame.open();
      return;
    }

    // Create the media frame.
    file_frame = wp.media.frames.file_frame = wp.media({
      title: jQuery( this ).data( 'uploader_title' ),
      button: { text: jQuery( this ).data( 'uploader_button_text' ) },
      library : { type : 'image'},
      multiple: true  // Set to true to allow multiple files to be selected
    });

  // When frame is open, select existing image attachments from custom field
  file_frame.on( 'open', function() {
    var selection = file_frame.state().get('selection');
    var attachment_ids = jQuery('#attachment_ids').val().split(',');
    attachment_ids.forEach(function(id) {
      attachment = wp.media.attachment(id);
      attachment.fetch();
      selection.add( attachment ? [ attachment ] : [] );
    });
  });

  // When images are selected, place IDs in hidden custom field and show thumbnails.
  file_frame.on( 'select', function() {

    var selection = file_frame.state().get('selection');

    // Place IDs in custom field
    var attachment_ids = selection.map( function( attachment ) {
      attachment = attachment.toJSON();
      return attachment.id;
    }).join();
    if( attachment_ids.charAt(0) === ',' ) { attachment_ids = attachment_ids.substring(1); }
    $('#attachment_ids').val( attachment_ids );


    // Show Thumbs
    var attachment_thumbs = selection.map( function( attachment ) {
      attachment = attachment.toJSON();
      console.log('attachment:', attachment);
      return '<img src="' + attachment.sizes.thumbnail.url + '" id="id-' + attachment.id + '" />';
    }).join(' ');
    $('#images-feedback').show();
    $('#thumbs').html(attachment_thumbs);

  });

    // Finally, open the modal
    file_frame.open();
  });


  // Place selected thumbnail ID into custom field to save as featured image
  $(document).on('click', '#thumbs img', function() {
     $('#thumbs img').removeClass('chosen');
     var thumb_ID = $(this).attr('id').substring(3);
     $('#wpuf_featured_img').val(thumb_ID);
     $(this).addClass('chosen');
  });

  // Show Thumbnails if exist
  if ( $('#attachment_ids').val() ) { $('#images-feedback').show(); }


});