I want to override the drupal core behavior Drupal.behaviors.filePreviewLinks which is located at core\modules\file\file.js from my custom module

I tried placing the following code in js file of my custom module

Drupal.behaviors.filePreviewLinks = {
    attach: function (context, settings) {
        console.log($(context).find('div.js-form-managed-file .file a'));
        //some custom code
    detach: function (context, settings){
       //some custom code

But it is not working. What I need to do? How to override Drupal core behavior in custom module?


Let me explain my actual question. I am loading a form in page that is created using ECK entity type module. One of a field in form has 'file' as field type. So once I upload a file, it is showing filename with link in a table(I hope it is default drupal feature). I want to remove the file link and show only file name.

  • Not enough info here. Are you attaching this file to the page? – Kevin Apr 6 '18 at 0:18
  • delete Drupal.behaviors.filePreviewLinks.attach; Drupal.behaviors.filePreviewLinks.detach; in your own library loaded afterwards. – user21641 Apr 6 '18 at 12:18

I do something similar in the Node Revision Delete module to override the drupal.content_types library doing this:

In the *.libraries.yml file define your library:

  version: 1.0.0
    js/content_types.js: {}
    - core/jquery
    - core/drupal
    - core/drupal.form

Attack your library where you need it:

  // Element to track the content type.
  $form['workflow']['section']['node_revision_delete_track'] = [
    '#type' => 'checkbox',
    '#title' => t('Limit the amount of revisions for this content type'),
    '#default_value' => $track,
    '#attached' => [
      'library' => [

And remove the core library:

 * Implements hook_library_info_alter().
function node_revision_delete_library_info_alter(&$libraries, $extension) {
  • This helps to override entire library file. It is working fine and I up-voted for this. Thanks. But, is it possible to override only particular behavior instead of entire library? – siddiq Apr 10 '18 at 3:36
  • @siddiq I don't know (is the first time that I see a problem like this), but you can duplicate the file and rewrite the function that you need to change. – Adrian Cid Almaguer Apr 10 '18 at 13:37

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