Can I put associative arrays in form inputs to be processed in PHP?

Question

I know I can do things like , but is it possible to do things like and have it show up

Answer 1

You can do this in Drupal too, quite easily. The important thing you have to remember about is setting form '#tree' parameter to TRUE. To give you a quick example:

function MYMODULE_form() {
  $form = array('#tree' => TRUE);
  $form['group_1']['field_1'] = array(
    '#type' => 'textfield',
    '#title' => 'Field 1',
  );
  $form['group_1']['field_2'] = array(
    '#type' => 'textfield',
    '#title' => 'Field 2',
  );
  $form['group_2']['field_3'] = array(
    '#type' => 'textfield',
    '#title' => 'Field 3',
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => 'Submit',
  );
  return $form;
}

Now, if you print_r() $form_state['values'] in MYMODULE_form_submit($form, &$form_state), you will see something like this:

Array
(
    [group_1] => Array
        (
            [field_1] => abcd
            [field_2] => efgh
        )

    [group_2] => Array
        (
            [field_3] => ijkl
        )

    [op] => Submit
    [submit] => Submit
    [form_build_id] => form-7a870f2ffdd231d9f76f033f4863648d
    [form_id] => test_form
)