[fw-mvc] Editable multi-row form

I'm looking to create a form (and necessary controller methods, etc) to edit multiple database rows at a time.

I've got some vague ideas of how to do it. However, I'm not sure how to tell the form __construct method (where the form is assembled) how many rows there are (This can only be known at runtime)

Should I just modify the __construct method call to add an extra parameter to specify this ?

I also assume I have to write my own Controller Action code to populate this form ?

Or is this a better way to do this ?

Thanks,

GTG