Drupal Multiupload Filefield Widget in Form API not really work?

Question

I have found the way to add Multiupload Filefield Widget into my custom form from this answer, https://drupal.stackexchange.com/questions/90637/does-multiupload-filefield-widget-for-drupal-provides-a-form-api-element/90658#90658?newreg=8dba9580e3d74b4d8b2cd1b140a4f08d

After adding the multiple file upload field into the form, and I try to upload some files, it won't show the list of uploaded files after the loading bar is gone.

Here is how I declare the field in my form:

$form['downloadsformset'] = array(
    '#type' => 'fieldset',
    '#title' => t('Downloads'),
    '#collapsible' => TRUE,
    '#group' => 'myform'
);
$form['downloadsformset']['download_items'] = array(
    '#type'  => 'mfw_managed_file',
    '#title' => t('Download items'),
    '#description' => t('You are allow to upload jpg, jpeg, png and gif'),
    '#progress_indicator' => 'bar',
        '#upload_location'    => "public://dev/tmp",
    "#upload_validators"  => array(
        "file_validate_extensions" => array("png jpg jpeg"),
        'file_validate_size' => array(1024*1024*1024),
    ),
    '#group' => 'myform'
);

What I have missed in order to show the uploaded file list?

Answer 1

You can try plupload module. This module also supports drag and drop file upload.

After installing module, you can do this in code,

$form['my_element'] = array(
  '#type' => 'plupload',

Answer 2

It seems that the Multiupload Filefield Widget is not really meant to be used in the form API.