How to submit a form to a different controller

Question

I have a simple blog application with the following associations:

Post hasMany Comment

Comment belongsTo Post

In the view for a post (PostsController::view action), existing comments are shown and there is a twitter modal popup which shows a form to add a comment.

What do I need to do to insert a new comment in the comments table, from the posts controller view action? How can I call one controller action from another?

If you load the add comment form in a modal, why can’t your form in that modal have an action of /comments/add or similar? — Martin Bean

AD7six AD7six · Accepted Answer · 2013-11-07T15:44:46

1. Create a controller action

Create a controller action used to process comment form submissions. This is a very simple (and dumb) example - enhance as required:

// Controller/CommentsContorller.php
class CommentsController extends AppController {

    public $components = array('RequestHandler');

    public function add() {
        $return = false;
        if ($this->request->data) {
            $return = $this->Comment->save($this->request->data);
        }

        if ($this->RequestHandler->isAjax()) {
            // return error or result as json
        }

        // fallback in case of direct access
        $this->redirect($this->referer());
    }
}

2. Create a comment form

Create a comment form, since you mention in the question using bootstrap modals, wrap the form in appropriate markup:

// View/Elements/comment_form.ctp
<!-- Button trigger modal -->
<button class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">
  Add a comment
</button>

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>     
        <h4 class="modal-title" id="myModalLabel">Modal title</h4>
      </div>
      <div class="modal-body">
        <?php
        echo $this->Form->create('Comment', array('url' => '/comments/add/'));
        echo $this->Form->inputs(array(
            'comment',
            'author'
        ));
        echo $this->Form->submit('add comment');
        ?>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button type="button" class="btn btn-primary">Save changes</button>
      </div>
    </div><!-- /.modal-content -->
  </div><!-- /.modal-dialog -->
</div><!-- /.modal -->

3. Include it in the relevant view file

With the element created, just include it somewhere appropriate, such as at the end of the posts index:

// View/Posts/index.ctp
...
echo $this->element('comment_form');

4. Submit by javascript

This step is optional.

With the above working the comment form should show up (via javascript) when clicking add comment but since it's a normal form it will be a normal http request upon submission. The comment form already works, don't change it, but most likely you'll want to add a form submission handler so that the form is submitted by ajax. In this way the user is not redirected away from the page.

Something like:

$('form#CommentAdd').submit(function(e) {
    e.preventDefault();

    $.post(
        $(this).attr('href'), 
        $(this).serialize(),
        function(result) {
            ...
            $('#myModal').modal('hide');
        }
    );
});