Drupal 7 - Hide 'remove' button on file field - drupal

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;
}