Question

Before I added dataType: "jsonp" my autocomplete was working. Now I need to make it cross domain compatible, thus using jsonp

I’ve added dataType: "jsonp" and ?callback= at the end of the URL.

But I still keep getting this error message:

Notice: Undefined index: callback in /var/www/storelocator/wp-content/themes/storelocator/classes/jquery.class.php on line 101

On line 101 I have the following code:
echo $_GET['callback'] . '('.json_encode($data).')';

My javascript looks like this:

  jQuery('.autocomplete_brand').autocomplete({
      source: siteURL +"/wp-content/themes/storelocator/include/jquery.php?instance=search_brand&limit=25?callback=",
      dataType: "jsonp",
      minLength: 2,
      search: function(event, ui) { jQuery(this).toggleClass( "autocomplete_loading" ); },
      open: function(event, ui) { jQuery(this).toggleClass( "autocomplete_loading" ); },
      select: function(event, ui) { jQuery('#ID').val(ui.item.id); }
  }).data( "autocomplete" )._renderItem = function( ul, item ) {
      return jQuery( "<li></li>" )
      .data( "item.autocomplete", item )
      .append( "<a>"+ item.value + "</a>" )
      .appendTo( ul );
      jQuery(this).toggleClass( "autocomplete_loading" );          
  }

Answer 1

jquery.php?instance=search_brand&limit=25?callback="

You have ? instead of & preceding the callback. Thus ‘callback’ is undefined in GET.