AHAH Example: Select control and generated checkboxes

Note that this is currently maintained in the Examples project so the code here may not be the latest.

In this example we use a select control to determine how many checkboxes are generated.

(Experience this one at http://d6.drupalexamples.info/examples/ahah_example/autocheckboxes.)

/**
* @file
* A Self-configure a form based on a select control
* Add the number of checkboxes specified in the select
*/
function ahah_demo_autocheckboxes(&$form_state) {

$default = !empty($form_state['values']['howmany']) ? $form_state['values']['howmany'] : 1;
$form['howmany'] = array(
'#title' => t('How many checkboxes do you want?'),
'#type' => 'select',
'#options' => array(1=>1, 2=>2, 3=>3, 4=>4),
'#default_value' => $default,
'#ahah' => array(
'path' => 'ahah_demo/autocheckboxes/callback',
'wrapper' => 'checkboxes',
'effect' => 'fade',
),

);

$form['checkboxes'] = array(
'#title' => t("Generated Checkboxes"),
'#prefix' => '

',
'#type' => 'fieldset',
'#description' => t('This is where we get automatically generated checkboxes'),
);

$num_checkboxes = !empty($form_state['values']['howmany']) ? $form_state['values']['howmany'] : 1;
for ($i=1; $i<=$num_checkboxes; $i++) {
$form['checkboxes']["checkbox$i"] = array(
'#type' => 'checkbox',
'#title' => "Checkbox $i",
);
}

$form['submit'] = array(
'#type' => 'submit',
'#value' => t('Click Me'),
);

return $form;
}

/**
* Callback for autocheckboxes. Process the form with the number of checkboxes
* we want to provide
*/
function ahah_demo_autocheckboxes_callback() {
$form_state = array('storage' => NULL, 'submitted' => FALSE);
$form_build_id = $_POST['form_build_id'];
$form = form_get_cache($form_build_id, $form_state);

$args = $form['#parameters'];
$form_id = array_shift($args);
$form_state['post'] = $form['#post'] = $_POST;
$form['#programmed'] = $form['#redirect'] = FALSE;

// HACK: Select values changing never get recognized
unset ($form['howmany']['#value']);

drupal_process_form($form_id, $form, $form_state);
$form = drupal_rebuild_form($form_id, $form_state, $args, $form_build_id);

$checkboxes = $form['checkboxes'];
$output = drupal_render($checkboxes);

// Final rendering callback.
print drupal_json(array('status' => TRUE, 'data' => $output));
exit();
}
?>