Drupal 7 - Hide 'remove' button on file field

Question

I have a content type with an image field. Users can create the content and upload an image. I'd like to not allow users to change/remove the image once it was uploaded, but still show the image on the node edit form. So I only need to disable/remove the 'remove' button from the image field. I tried the following (via hook_form_alter), but it didn't work:

$form['field_image']['#disabled'] = TRUE;

The below works, but it hides the image element completely, which is not what I'm after:

$form['field_image']['#access'] = FALSE;

Please help to find a workaround.

Answer 1

You have to use the hook_field_widget_form_alter function and inside there look for the variable details using dpm() and then alter the button using an attribute from the Forms API.

But I would suggest to make the widget field read only on the edit form and not remove the delete button.

// Hide remove button from an image field
function MYMODULE_field_widget_form_alter(&$element, &$form_state, $context) {
  // If this is an image field type
  if ($context['field']['field_name'] == 'MY_FIELD_NAME') {
    // Loop through the element children (there will always be at least one).
    foreach (element_children($element) as $key => $child) {
      // Add the new process function to the element
      $element[$key]['#process'][] = 'MYMODULE_image_field_widget_process';
    }
  }
}

function MYMODULE_image_field_widget_process($element, &$form_state, $form) {
  //dpm($element);
  // Hide the remove button
  $element['remove_button']['#type'] = 'hidden';

  // Return the altered element
  return $element;
}

Useful issues:

• Drupal 7: How to alter image field widget "alt" or title" label
• How to disable a field or make it readonly in Drupal 7
• https://drupal.stackexchange.com/q/32861/12163

Answer 2

You can also do it using hook_form_alter and after_build function

// hook_form_alter implementation
function yourmodule_form_alter(&$form, $form_state, $form_id) {
    switch ($form_id)  {
        case 'your_form_id':
            $form['your_file_field'][LANGUAGE_NONE]['#after_build'][] = 'yourmodule_hide_remove_button';
            break;
    }
}

// after_build function
function yourmodule_hide_remove_button($element, &$form_state) {
    // if multiple files are allowed in the field, then there may be more than one remove button.
    // and we have to hide all remove buttons, not just the one of the first file of the field
    // 
    // Array
    // (
    //    [0] => 0
    //    [1] => 1
    //    [2] => #after_build
    //    [3] => #field_name
    //    [4] => #language
    //    [5] => ...
    // )
    //
    // the exemple above means we have 2 remove buttons to hide (2 files have been uploaded)

    foreach ($element as $key => $value){
        if (is_numeric($key)){
            unset($element[$key]['remove_button']);
        } else break;
    }

    return $element;
}