DooPHP related data in form

Question

i would like to ask if there is any method to render form for related data?

e.g

suppose we have a financial app. We could have Transactions and Categories (categories hasMany transactions).

Transaction Entity

id, amount, category_id

Category Entity

id, name

So far so good, but in the form i want to render an element (a select tag), so the user can select the categories form category model. Something like this:

      <select name="demo"><option value="category_id">category_name</option>

Also,following the ORM mechanism, i set mapping like

      $dbmap['Category']['has_many']['Transaction'] = array('foreign_key'=>'category_id');

      $dbmap['Transaction']['belongs_to']['Category'] = array('foreign_key'=>'id');

I can build the form manually, i could create a function in category model (e.g get_categories) and then in the controller, just load the model and send the categories to the view. Is this the correct way? or there is a different, most appropriate way?