Same name and namespace in other branches
  1. 10 core/lib/Drupal/Core/Form/form.api.php \hook_form_alter()
  2. 4.7.x developer/hooks/core.php \hook_form_alter()
  3. 6.x developer/hooks/core.php \hook_form_alter()
  4. 7.x modules/system/system.api.php \hook_form_alter()
  5. 8.9.x core/lib/Drupal/Core/Form/form.api.php \hook_form_alter()
  6. 9 core/lib/Drupal/Core/Form/form.api.php \hook_form_alter()

Perform alterations before a form is rendered.

One popular use of this hook is to add form elements to the node form. When altering a node form, the node object retrieved at from $form['#node'].

Parameters

$form_id: String representing the name of the form itself. Typically this is the name of the function that generated the form.

$form: Nested array of form elements that comprise the form.

Return value

None.

Related topics

11 functions implement hook_form_alter()

Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

color_form_alter in modules/color/color.module
Implementation of hook_form_alter().
comment_form_alter in modules/comment/comment.module
forum_form_alter in modules/forum/forum.module
Implementation of hook_form_alter().
menu_form_alter in modules/menu/menu.module
Implementation of hook_form_alter(). Add menu item fields to the node form.
multipage_form_example_form_alter in developer/examples/multipage_form_example.module
Implementation of hook_form_alter(). Here, we set up the 'page' field, which keeps track of what stage the form is in.

... See full list

File

developer/hooks/core.php, line 438
These are the hooks that are invoked by the Drupal core.

Code

function hook_form_alter($form_id, &$form) {
  if (isset($form['type']) && $form['type']['#value'] . '_node_settings' == $form_id) {
    $form['workflow']['upload_' . $form['type']['#value']] = array(
      '#type' => 'radios',
      '#title' => t('Attachments'),
      '#default_value' => variable_get('upload_' . $form['type']['#value'], 1),
      '#options' => array(
        t('Disabled'),
        t('Enabled'),
      ),
    );
  }
}