'markup',
'#value' => '' . t('This is an example of a properly degrading dynamic form. It will work correctly with or without AJAX enabled. However, it has to provide an extra hidden button to change the values in the dependent dropdown.') . '
',
);
// if we have a value for the first dropdown from $form_state['values'] we use
// this both as the default value for the first dropdown and also as a
// parameter to pass to the function that retrieves the options for the
// second dropdown.
$master_selection = !empty($form_state['values']['master_dropdown']) ? $form_state['values']['master_dropdown'] : t('Strings');
$form['master_dropdown'] = array(
'#type' => 'select',
'#title' => 'Master Dropdown',
'#options' => $initial_options,
'#default_value' => $master_selection,
'#ahah' => array(
'path' => 'examples/ahah_example/dependent_dropdown/callback',
'wrapper' => 'dependent-dropdown-wrapper',
// 'event' => 'change', // default value: does not need to be set explicitly.
),
'#attributes' => array('class' => 'master-dropdown'),
);
// The CSS for this module hides this next button if JS is enabled.
$form['continue_to_dependent_dropdown'] = array(
'#type' => 'submit',
'#value' => t('Choose'),
'#attributes' => array('class' => 'next-button'),
'#submit' => array('ahah_example_dropdown_continue'),
);
$form['dependent_dropdown_holder'] = array(
'#tree' => TRUE,
'#prefix' => '',
'#suffix' => '
',
);
$form['dependent_dropdown_holder']['dependent_dropdown'] = array(
'#type' => 'select',
'#title' => t('Dependent Dropdown (changes based on master dropdown)'),
// when the form is rebuilt during processing (either AJAX or multistep),
// the $master_selction variable will now have the new value and so the
// options will change.
'#options' => _ahah_example_get_second_dropdown_options($master_selection),
'#default_value' => isset($my_values['dependent_dropdown']) ? $my_values['dependent_dropdown'] : '',
);
$form['submit'] = array(
'#type' => 'submit',
'#value' => t('Save'),
);
return $form;
}
/**
* The AHAH callback. It processes the form using ahah_example_callback_helper()
* and then
*/
function ahah_example_dropdown_callback() {
$form = ahah_example_callback_helper();
$changed_elements = $form['dependent_dropdown_holder'];
// Prevent duplicate wrappers.
unset($changed_elements['#prefix'], $changed_elements['#suffix']);
$output = theme('status_messages') . drupal_render($changed_elements);
drupal_json(array(
'status' => TRUE,
'data' => $output,
));
}
/**
* Submit handler for 'continue_to_dependent_dropdown'.
*/
function ahah_example_dropdown_continue($form, &$form_state) {
$values = $form_state['values'];
unset($form_state['submit_handlers']);
form_execute_handlers('submit', $form, $form_state);
$form_state['my_values'] = $values;
$form_state['rebuild'] = TRUE;
}
/**
* Default submit handler for form. This one happens when the main submit
* button is pressed.
*/
function ahah_example_dropdown_submit($form, &$form_state) {
// If an AHAH submission, it's just the dependent dropdown working.
if (!empty($form_state['ahah_submission'])) {
return;
}
if ($form_state['clicked_button']['#id'] == 'edit-submit') {
$form_state['rebuild'] = FALSE;
drupal_set_message(t('Your values have been submitted. master_dropdown=@first, dependent_dropdown=@second', array('@first' => $form_state['values']['master_dropdown'], '@second' => $form_state['values']['dependent_dropdown_holder']['dependent_dropdown'])));
}
// edit-next or anything else will cause rebuild.
$form_state['rebuild'] = TRUE;
}
/**
* Helper function to populate the first dropdown. This would normally be
* pulling data from the database.
*
* @return array of options
*/
function _ahah_example_get_first_dropdown_options() {
// drupal_map_assoc() just makes an array('Strings' => 'Strings'...).
return drupal_map_assoc(array(t('Strings'), t('Woodwinds'), t('Brass'), t('Percussion')));
}
/**
* Helper function to populate the second dropdown. This would normally be
* pulling data from the database.
*
* @param key. This will determine which set of options is returned.
*
* @return array of options
*/
function _ahah_example_get_second_dropdown_options($key = '') {
$options = array(
t('Strings') => drupal_map_assoc(array(t('Violin'), t('Viola'), t('Cello'), t('Double Bass'))),
t('Woodwinds') => drupal_map_assoc(array(t('Flute'), t('Clarinet'), t('Oboe'), t('Bassoon'))),
t('Brass') => drupal_map_assoc(array(t('Trumpet'), t('Trombone'), t('French Horn'), t('Euphonium'))),
t('Percussion') => drupal_map_assoc(array(t('Bass Drum'), t('Timpani'), t('Snare Drum'), t('Tambourine'))),
);
if (isset($options[$key])) {
return $options[$key];
}
else {
return array();
}
}