A quick tip about symfony's admin generator: if you want to have a custom action, with the following generator.yml bit for example (actions prefixed with an underscore are builtin admin-gen actions):

form:
  actions:
    _delete:  ~
    _cancel:  ~
    _save:    ~
    _save_and_add: ~
    custom: ~

You can totally customize the link generated for this action (to add javascript for example) using the generator helper in your module's lib/ directory:

[php]
public function linkToCustom($object, $params)
{
  return '<a href="#" onclick="console.log(\'woohoo\'); return false;">log woohoo</a>';
}

You get passed the current object as an argument, and whatever parameters you passed in the generator.yml:

    custom: { label: 'WOOHOO' }

[php]
public function linkToCustom($object, $params)
{
  return '<a href="'.url_for($this->getUrlForAction('custom')).'" onclick="console.log(\'woohoo\'); return false;">'.__($params['label']).'</a>';
}

Also, as you can see that standard helpers are available too.