There's no built in way but as drupal_add_library()
uses Drupal's static pattern you can find out by doing this:
function ui_is_included() {
// Get the list of libraries included in this page load
$libs = drupal_static('drupal_add_library');
// The system library will pretty much always exist as it includes jQuery,
// but it's just good sense to check just in case.
if (isset($libs['system'])) {
// If the system library array includes UI then make sure it's enbabled
return isset($libs['system']['ui']) && $libs['system']['ui'] === TRUE;
}
// UI is not loaded if we've got to this point
return FALSE;
}
You can even compress that down a bit:
function ui_is_included() {
$libs = drupal_static('drupal_add_library');
return isset($libs['system']['ui']) && $libs['system']['ui'];
}
I'd advise calling this function as late on in the page build process as possible, to ensure that all modules have had a chance to request that UI is added. hook_preprocess_html()
in your theme's template.php
file might be a good place to put it.