kriswallsmith/sfDoctrineDynamicFormRelationsPlugin

This plugin allows you to embed related forms in a Doctrine form class,
manipulate those embedded forms using JavaScript (i.e. add more, remove some,
etc), and will automatically update those relations when the form is
processed.

class AuthorForm extends BaseAuthorForm
{
  public function configure()
  {
    $this->embedDynamicRelation('books');
  }
}

This form can now be rendered something like this, enhanced with JavaScript:

<form action="#" method="post">
  <!-- ... -->
  <ul>
    <?php foreach ($form['books'] as $bookFields): ?>
      <li>
        <table><?php echo $bookFields ?></table>
        <a href="javascript:remove_book(this)">remove this book</a>
      </li>
    <?php endforeach ?>
  </ul>
  <a href="javascript:add_book()">add another book</a>
  <!-- ... -->
</form>

Once your JavaScript is setup (which is up to you), your user can remove some
of the listed books and add a few more. When you submit the form the database
will be updated to reflect those changes.

Limitations

• The primary key of the related model must be "id"
• The embedded form class must include an "id" field

Roadmap

• Detect the related model's primary key
• Obfuscate and add the primary key for embedded forms when needed