How can I add a cancel button to the content add form for a single content type?

Question

I have several content types on a site and most of them are user-editable but not user-creatable. However, one content type, Image, allows users to upload a picture. Sometimes, however, users upload the wrong picture and they panic because they don't want that picture to be submitted to the site.

Of course they could always hit the browser's back button, but I'd like to add a Cancel button for additional assurance.

I found this thread that gives various solutions for adding cancel buttons on Drupal.org as well as this feature request for adding a cancel button to D8. However, there are several different general approaches and I don't know how to limit one to a given content type (in this case, my_image).

Answer 1

I would use the following code.

function mymodule_form_my_image_node_form_alter(&$form, &$form_state) {
  // This is a new node; the form is creating a new node.
  if (!isset($node->nid) || isset($node->is_new)) {
    $destination = 'node/add';
  }
  else {
    $destination = "node/{$node->nid}";
  }

  $form['actions']['cancel'] = array(
    '#markup' => l(t('Cancel'), $destination),
    '#weight' => 20,
  );
}  

This is the version without IF statement.

function mymodule_form_my_image_node_form_alter(&$form, &$form_state) {
  $destination = (!isset($node->nid) || isset($node->is_new)) ? 'node/add' : "node/{$node->nid}";

  $form['actions']['cancel'] = array(
    '#markup' => l(t('Cancel'), $destination),
    '#weight' => 20,
  );
}  

Notice that:

• markup is the default form element type; there is no need to use #type = 'markup'.

• In the node edit form, all the buttons are inside $form['actions']. The weights used from the buttons that form is using are 5 (Save), 10 (Preview), and 15 (Delete). I used 20 to show the link after those buttons, but you can change its weight to show it in a different position.

  // Add the buttons.
  $form['actions'] = array('#type' => 'actions');
  $form['actions']['submit'] = array(
    '#type' => 'submit', 
    '#access' => variable_get('node_preview_' . $node->type, DRUPAL_OPTIONAL) != DRUPAL_REQUIRED || (!form_get_errors() && isset($form_state['node_preview'])), 
    '#value' => t('Save'), 
    '#weight' => 5, 
    '#submit' => array('node_form_submit'),
  );
  $form['actions']['preview'] = array(
    '#access' => variable_get('node_preview_' . $node->type, DRUPAL_OPTIONAL) != DRUPAL_DISABLED, 
    '#type' => 'submit', 
    '#value' => t('Preview'), 
    '#weight' => 10, 
    '#submit' => array('node_form_build_preview'),
  );
  if (!empty($node->nid) && node_access('delete', $node)) {
    $form['actions']['delete'] = array(
      '#type' => 'submit', 
      '#value' => t('Delete'), 
      '#weight' => 15, 
      '#submit' => array('node_form_delete_submit'),
    );
  }
  

• There isn't the need to use arg() to understand if the form is for editing an existing node, or for creating a new one. I checked !isset($node->nid) || isset($node->is_new) is TRUE, to verify the node is being created. Drupal seems to simply check empty($node->nid), even though node_object_prepare() uses !isset($node->nid) || isset($node->is_new).

• If $_GET['destination'] is set, the link added with l() will point to that path.

Answer 2

Each node form has its own unique id. It's consisted of node type's machine name followed by _node_form. So your my_image node type's form id is my_image_node_form

Here's a mock untested function to illustrate how to implement:

function HOOK_form_alter(&$form, &$form_state, $form_id) {
  $types = array(
    'my_image',
  );

  foreach($types as $type) {
    if($type.'_node_form' == $form_id) {
      if(arg(1) == 'add') {
        // If adding node link to node/add screen
        $link = l(t('Cancel'), 'node/add');
      }
      elseif(arg(2) == 'edit') {
        // If editing node, link to node view screen
        $link = l(t('Cancel'), 'node/'.arg(1));
      }
      $form['cancel'] = array(
        '#type' => 'markup',
        '#value' => $link,
        '#weight' => 0,
      );
    }
  }
}

Answer 3

You can do that using the hook form alter:

function myModule_form_alter($form_state,$form_id){
 if($form_id=='myFormId'){
  // add the cancell button to your form
 }
}

Give that a shot.

Answer 4

There's a module for that!: http://drupal.org/project/nodeformsettings ... and this module is really fantastic. It's worth to check out.

Answer 5

All those solutions are for adding Cancel link not a button!

If you want to add the button instead of a link you should use this code for module cancel_button.module:

function cancel_button_form_alter(&$form, &$form_state, $form_id) {
    // node types for which Cancel button should be added
    $types = array(
      'biography',
      'faq',
      'draftlaw',
      'vocabulary',
      'draftlaw_page',
      'encyclopedia',
      'user', // if you want to add user's edit form too
    );

    foreach($types as $type) {
        if($type.'_node_form' == $form_id || $type.'_profile_form' == $form_id) {
            $form['actions']['cancel'] = array(
                '#type'   => 'submit',
                '#value'  => t('Cancel'),
                '#access' => TRUE,
                '#weight' => 55,
                '#submit' => array('cancel_button_form_cancel', 'node_form_submit_build_node'),
                '#limit_validation_errors' => array(),
                );
            }
        }
    }

    /**
     * cancel_button callback.
     */
    function cancel_button_form_cancel($form, &$form_state) {
        $link = '';
        $path = 'node';
        if('user_profile_form' == $form['#form_id']){
            $path = 'user';
        }
        if(arg(1) == 'add') {
            // If adding entity link to [user|node]/add screen
            $link = $path . '/add';
        }
        elseif(arg(2) == 'edit') {
            // If editing entity, link to node view screen
            $link = $path . '/' . arg(1);
        }
        $url = $_GET['destination'] ? $_GET['destination'] : $link;
        drupal_goto($url);
    }