field_attach_form removes image field default value when submit

Question

I need to get some fields of a node edit form, for that purpose I use field_attach_form() to get the fields that I want with the value of the node.

Here's an example of the code of my form function:

function my_form($form, &$form_state, $node_id, $fields) {
  $node = node_load($node_id);
  $node_form = $form;
  field_attach_form('node', $node, $node_form, $form_state);

  foreach ($fields as $field) {
    if ($field->show) {
      $form[$field->name] = array('#type' => 'fieldset', '#title' => t('Field'), '#tree' => TRUE,);
      $form[$field->name]['override'] = array('#type' => 'checkbox', '#title' => t('Override'),);
      $form[$field->name][$field->name] = $node_form[$field->name];
      $form[$field->name][$field->name]['#states'] = array(
        'enabled' => array(
          ':input[name="' . $field->name . '[override]"]' => array('checked' => TRUE)
        ),
      );
    }
  }

  return $form;
}

I just wrap every field (that I want to show) in a fieldset with a checkbox.

One of the field is an image type, when field_attach_form loads the field, it shows the image thumbnail and the image file name perfectly, but when I click submit (without edit the field content) the value of the field is empty. In fact, the image field is required so the validation fails.

When I remove the previous image and upload a new one, it works perfectly. Am I missing something?

Answer 1

I found a workaround: I just have the fields twice, one enabled and the other disabled. With the checkbox I show one or another.

function my_form($form, &$form_state, $node_id, $fields) {
  $node = node_load($node_id);
  $node_form = $form;
  field_attach_form('node', $node, $node_form, $form_state);

  foreach ($fields as $field) {
    if ($field->show) {
      $form[$field->name] = array('#type' => 'fieldset', '#title' => t('Field'), '#tree' => TRUE,);

      $form[$field->name]['override'] = array('#type' => 'checkbox', '#title' => t('Override'),);

      $form[$field->name][$field->name] = $node_form[$field->name];
      $form[$field->name][$field->name]['#states'] = array(
        'visible' => array(
          ':input[name="' . $field->name . '[override]"]' => array('checked' => TRUE)
        ),
      );

      $form[$field->name][$field->name . 'disabled'] = $node_form[$field->name];
      $form[$field->name][$field->name . 'disabled']['#disabled'] = TRUE;
      $form[$field->name][$field->name . 'disabled']['#states'] = array(
        'visible' => array(
          ':input[name="' . $field->name . '[override]"]' => array('checked' => FALSE)
        ),
      );
    }
  }

  return $form;
}

It seems that the action enabled / disabled is buggy.