jQuery attribute selectors: How to query for an attribute with a custom namespace

jQuery does not support custom namespaces directly, but you can find the divs you are looking for by using filter function.

// find all divs that have custom:attr
$('div').filter(function() { return $(this).attr('custom:attr'); }).each(function() {
  // matched a div with custom::attr
  $(this).html('I was found.');
});