xhr2_uploadprogress

This module adds an alternative to the standard core-provided *bar* (with pecl uploadprogress) upload progress widget with new XHR2 upload monitoring support in browsers via xhr.upload.progress.

Note: This is an API module and is targeted towards module developers.

Pitfalls:

1. The beforeSend function had to be overriden from core to add support for setting up XHR uploadprogress (see xhr2_uploadprogress.js)
2. It might not work (NOT TESTED) on older browsers like IE 8, 9 etc.

How to use

1. Install the module as usually: https://www.drupal.org/node/895232
2. In your form class, you configure the field #type as xhr2_managed_file, example:

 $form['files'] = [
        '#type' => 'xhr2_managed_file',
        '#title' => t('Add files'),
        '#progress_indicator' => 'xhr2',
        '#required' => true,
        '#multiple' => true,
        '#upload_validators' => ['file_validate_extensions' => [$field_definition->getSetting('file_extensions')]],
        '#weight' => 3,
      ];
   ```

When you upload files, the system should display a progress bar that tracks the form submission progress.

Supported also by Holcim România.