dropdownexaple

<?php

/**
 * @file
 * AJAX Examples module file with basic examples.
 */

/**
 * @defgroup ajax_example Example: AJAX
 * @ingroup examples
 * @{
 * These examples show basic AJAX concepts.
 *
 * General documentation is available at
 * @link ajax AJAX Framework documentation @endlink and at the
 * @link http://drupal.org/node/752056 AJAX Forms handbook page @endlink.
 *
 * The several examples here demonstrate basic AJAX usage.
 */

// The Node Form Alter example needs to be in another file.
module_load_include('inc', 'ajax_example', 'ajax_example_node_form_alter');

/**
 * Implements hook_menu().
 *
 * Sets up calls to drupal_get_form() for all our example cases.
 *
 * @see menu_example.module for more details on hook_menu().
 */
function ajax_example_menu() {
  $items = array();

  $items['examples/ajax_example'] = array(
    'title' => 'AJAX Example',
    'page callback' => 'ajax_example_intro',
    'access callback' => TRUE,
    'expanded' => TRUE,
  );

  // Change the description of a form element.
  $items['examples/ajax_example/simplest'] = array(
    'title' => 'Simplest AJAX Example',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_simplest'),
    'access callback' => TRUE,
    'weight' => 0,
  );
  // Generate a changing number of checkboxes.
  $items['examples/ajax_example/autocheckboxes'] = array(
    'title' => 'Generate checkboxes',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_autocheckboxes'),
    'access callback' => TRUE,
    'weight' => 1,
  );
  // Generate different textfields based on form state.
  $items['examples/ajax_example/autotextfields'] = array(
    'title' => 'Generate textfields',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_autotextfields'),
    'access callback' => TRUE,
    'weight' => 2,
  );

  // Submit a form without a page reload.
  $items['examples/ajax_example/submit_driven_ajax'] = array(
    'title' => 'Submit-driven AJAX',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_submit_driven_ajax'),
    'access callback' => TRUE,
    'weight' => 3,
  );

  // Repopulate a dropdown based on form state.
  $items['examples/ajax_example/dependent_dropdown'] = array(
    'title' => 'Dependent dropdown',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_dependent_dropdown'),
    'access callback' => TRUE,
    'weight' => 4,
  );
  // Repopulate a dropdown, but this time with graceful degredation.
  // See ajax_example_graceful_degradation.inc.
  $items['examples/ajax_example/dependent_dropdown_degrades'] = array(
    'title' => 'Dependent dropdown (with graceful degradation)',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_dependent_dropdown_degrades'),
    'access callback' => TRUE,
    'weight' => 5,
    'file' => 'ajax_example_graceful_degradation.inc',
  );
  // The above example as it appears to users with no javascript.
  $items['examples/ajax_example/dependent_dropdown_degrades_no_js'] = array(
    'title' => 'Dependent dropdown with javascript off',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_dependent_dropdown_degrades', TRUE),
    'access callback' => TRUE,
    'file' => 'ajax_example_graceful_degradation.inc',
    'weight' => 5,
  );

  // Populate a form section based on input in another element.
  $items['examples/ajax_example/dynamic_sections'] = array(
    'title' => 'Dynamic Sections (with graceful degradation)',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_dynamic_sections'),
    'access callback' => TRUE,
    'weight' => 6,
    'file' => 'ajax_example_graceful_degradation.inc',
  );
  // The  above example as it appears to users with no javascript.
  $items['examples/ajax_example/dynamic_sections_no_js'] = array(
    'title' => 'Dynamic Sections w/JS turned off',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_dynamic_sections', TRUE),
    'access callback' => TRUE,
    'weight' => 6,
    'file' => 'ajax_example_graceful_degradation.inc',
  );

  // A classic multi-step wizard, but with no page reloads.
  // See ajax_example_graceful_degradation.inc.
  $items['examples/ajax_example/wizard'] = array(
    'title' => 'Wizard (with graceful degradation)',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_wizard'),
    'access callback' => TRUE,
    'file' => 'ajax_example_graceful_degradation.inc',
    'weight' => 7,
  );
  // The above example as it appears to users with no javascript.
  $items['examples/ajax_example/wizard_no_js'] = array(
    'title' => 'Wizard w/JS turned off',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_wizard', TRUE),
    'access callback' => TRUE,
    'file' => 'ajax_example_graceful_degradation.inc',
    'weight' => 7,
  );

  // Add-more button that creates additional form elements.
  // See ajax_example_graceful_degradation.inc.
  $items['examples/ajax_example/add_more'] = array(
    'title' => 'Add-more button (with graceful degradation)',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_add_more'),
    'access callback' => TRUE,
    'file' => 'ajax_example_graceful_degradation.inc',
    'weight' => 8,
  );
  // The above example as it appears to users with no javascript.
  $items['examples/ajax_example/add_more_no_js'] = array(
    'title' => 'Add-more button w/JS turned off',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_add_more', TRUE),
    'access callback' => TRUE,
    'file' => 'ajax_example_graceful_degradation.inc',
    'weight' => 8,
  );

  // Use the AJAX framework outside the context of a form using the use-ajax
  // class. See ajax_example_misc.inc.
  $items['examples/ajax_example/ajax_link'] = array(
    'title' => 'Ajax Link ("use-ajax" class)',
    'page callback' => 'ajax_example_render_link',
    'access callback' => TRUE,
    'file' => 'ajax_example_misc.inc',
    'weight' => 9,
  );
  // Use the AJAX framework outside the context of a form using a renderable
  // array of type link with the #ajax property. See ajax_example_misc.inc.
  $items['examples/ajax_example/ajax_link_renderable'] = array(
    'title' => 'Ajax Link (Renderable Array)',
    'page callback' => 'ajax_example_render_link_ra',
    'access callback' => TRUE,
    'file' => 'ajax_example_misc.inc',
    'weight' => 9,
  );
  // A menu callback is required when using ajax outside of the Form API.
  $items['ajax_link_callback'] = array(
    'page callback' => 'ajax_link_response',
    'access callback' => 'user_access',
    'access arguments' => array('access content'),
    'type' => MENU_CALLBACK,
    'file' => 'ajax_example_misc.inc',
  );

  // Use AJAX framework commands outside of the #ajax form property.
  // See ajax_example_advanced.inc.
  $items['examples/ajax_example/advanced_commands'] = array(
    'title' => 'AJAX framework commands',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ajax_example_advanced_commands'),
    'access callback' => TRUE,
    'file' => 'ajax_example_advanced.inc',
    'weight' => 10,
  );

  return $items;
}

function ajax_example_intro() {
  $markup = t('The AJAX example module provides many examples of AJAX including forms, links, and AJAX commands.');
  return $markup;
}

/**
 * Simple form whose ajax-enabled 'changethis' member causes a text change
 * in the description of the 'replace_textfield' member.
 * See @link http://drupal.org/node/262422 Form API Tutorial @endlink
 */
function ajax_example_simplest($form, &$form_state) {
  $form = array();
  $form['changethis'] = array(
    '#title' => t("Choose something and explain why"),
    '#type' => 'select',
    '#options' => array(
      'one' => 'one',
      'two' => 'two',
      'three' => 'three',
    ),
    '#ajax' => array(
      // #ajax has two required keys: callback and wrapper.
      // 'callback' is a function that will be called when this element changes.
      'callback' => 'ajax_example_simplest_callback',
      // 'wrapper' is the HTML id of the page element that will be replaced.
      'wrapper' => 'replace_textfield_div',
      // There are also several optional keys - see ajax_example_autocheckboxes
      // below for details on 'method', 'effect' and 'speed' and
      // ajax_example_dependent_dropdown for 'event'.
     ),
  );

  // This entire form element will be replaced whenever 'changethis' is updated.
  $form['replace_textfield'] = array(
    '#type' => 'textfield',
    '#title' => t("Why"),
    // The prefix/suffix provide the div that we're replacing, named by
    // #ajax['wrapper'] above.
    '#prefix' => '<div id="replace_textfield_div">',
    '#suffix' => '</div>',
  );

  // An AJAX request calls the form builder function for every change.
  // We can change how we build the form based on $form_state.
  if (!empty($form_state['values']['changethis'])) {
    $form['replace_textfield']['#description'] = t("Say why you chose '@value'", array('@value' => $form_state['values']['changethis']));
  }
  return $form;
}

/**
 * Callback for ajax_example_simplest.
 *
 * On an ajax submit, the form builder function is called again, then the $form
 * and $form_state are passed to this callback function so it can select which
 * portion of the form to send on to the client.
 *
 * @return renderable array (the textfield element)
 */
function ajax_example_simplest_callback($form, $form_state) {
  // The form has already been submitted and updated. We can return the replaced
  // item as it is.
  return $form['replace_textfield'];
}

/**
 * AJAX-enabled select element causes replacement of a set of checkboxes
 * based on the selection.
 */
function ajax_example_autocheckboxes($form, &$form_state) {
  // Since the form builder is called after every AJAX request, we rebuild
  // the form based on $form_state.
  $num_checkboxes = !empty($form_state['values']['howmany_select']) ? $form_state['values']['howmany_select'] : 1;

  $form['howmany_select'] = array(
    '#title' => t('How many checkboxes do you want?'),
    '#type' => 'select',
    '#options' => array(1 => 1, 2 => 2, 3 => 3, 4 => 4),
    '#default_value' => $num_checkboxes,
    '#ajax' => array(
      'callback' => 'ajax_example_autocheckboxes_callback',
      'wrapper' => 'checkboxes-div',
      //'method' defaults to replaceWith, but valid values also include
      // append, prepend, before and after.
      // 'method' => 'replaceWith',
      // 'effect' defaults to none. Other valid values are 'fade' and 'slide'.
      // See ajax_example_autotextfields for an example of 'fade'.
      'effect' => 'slide',
      // 'speed' defaults to 'slow'. You can also use 'fast'
      // or a number of milliseconds for the animation to last.
      // 'speed' => 'slow',
      // Don't show any throbber...
      'progress' => array('type' => 'none'),
    ),
  );


  $form['checkboxes_fieldset'] = array(
    '#title' => t("Generated Checkboxes"),
    // The prefix/suffix provide the div that we're replacing, named by
    // #ajax['wrapper'] above.
    '#prefix' => '<div id="checkboxes-div">',
    '#suffix' => '</div>',
    '#type' => 'fieldset',
    '#description' => t('This is where we get automatically generated checkboxes'),
  );

  for ($i = 1; $i <= $num_checkboxes; $i++) {
    $form['checkboxes_fieldset']["checkbox$i"] = array(
      '#type' => 'checkbox',
      '#title' => "Checkbox $i",
    );
  }

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

  return $form;
}

/**
 * Callback element needs only select the portion of the form to be updated.
 * Since #ajax['callback'] return can be HTML or a renderable array (or an
 * array of commands), we can just return a piece of the form.
 * See @link ajax_example_advanced.inc AJAX Advanced Commands for more details
 * on AJAX framework commands.
 *
 * @return renderable array (the checkboxes fieldset)
 */
function ajax_example_autocheckboxes_callback($form, $form_state) {
  return $form['checkboxes_fieldset'];
}


/**
 * Show/hide textfields based on AJAX-enabled checkbox clicks.
 */
function ajax_example_autotextfields($form, &$form_state) {

  $form['ask_first_name'] = array(
    '#type' => 'checkbox',
    '#title' => t('Ask me my first name'),
    '#ajax' => array(
      'callback' => 'ajax_example_autotextfields_callback',
      'wrapper' => 'textfields',
      'effect' => 'fade',
    )
  );
  $form['ask_last_name'] = array(
   '#type' => 'checkbox',
   '#title' => t('Ask me my last name'),
    '#ajax' => array(
      'callback' => 'ajax_example_autotextfields_callback',
      'wrapper' => 'textfields',
      'effect' => 'fade',
    ),
  );

  $form['textfields'] = array(
    '#title' => t("Generated text fields for first and last name"),
    '#prefix' => '<div id="textfields">',
    '#suffix' => '</div>',
    '#type' => 'fieldset',
    '#description' => t('This is where we put automatically generated textfields'),
  );

  // Since checkboxes return TRUE or FALSE, we have to check that
  // $form_state has been filled as well as what it contains.
  if (!empty($form_state['values']['ask_first_name']) && $form_state['values']['ask_first_name']) {
    $form['textfields']['first_name'] = array(
      '#type' => 'textfield',
      '#title' => t('First Name'),
    );
  }
  if (!empty($form_state['values']['ask_last_name']) && $form_state['values']['ask_last_name']) {
    $form['textfields']['last_name'] = array(
      '#type' => 'textfield',
      '#title' => t('Last Name'),
    );
  }

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

  return $form;
}

/**
 * Selects the piece of the form we want to use as replacement text and returns
 * it as a form (renderable array).
 *
 * @return renderable array (the textfields element)
 */
function ajax_example_autotextfields_callback($form, $form_state) {
  return $form['textfields'];
}


/**
 * A very basic form which with an AJAX-enabled submit.
 *
 * On submit, the markup in the #markup element is updated.
 */
function ajax_example_submit_driven_ajax($form, &$form_state) {
  $form['box'] = array(
    '#type' => 'markup',
    '#prefix' => '<div id="box">',
    '#suffix' => '</div>',
    '#markup' => '<h1>Initial markup for box</h1>',
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#ajax' => array(
      'callback' => 'ajax_example_submit_driven_callback',
      'wrapper' => 'box',
      'name' => 'submit1',
    ),
    '#value' => t('Submit'),
  );

  return $form;
}

/**
 * Select the 'box' element, change the markup in it, and return it as a
 * renderable array.
 *
 * @return renderable array (the box element)
 */
function ajax_example_submit_driven_callback($form, $form_state) {
  // In most cases, it is recomended that you put this logic in form generation
  // rather than the callback. Submit driven forms are an exception, because
  // you may not want to return the form at all.
  $element = $form['box'];
  $element['#markup'] = "Clicked submit ({$form_state['values']['op']}): " . date('c');
  return $element;
}


/**
 * A form with a dropdown whose options are dependent on a
 * choice made in a previous dropdown.
 *
 * On changing the first dropdown, the options in the second
 * are updated.
 */
function ajax_example_dependent_dropdown($form, &$form_state) {
  // Get the list of options to populate the first dropdown.
  $options_first = _ajax_example_get_first_dropdown_options();
  // 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.
  $selected = isset($form_state['values']['dropdown_first']) ? $form_state['values']['dropdown_first'] : key($options_first);

  $form['dropdown_first'] = array(
    '#type' => 'select',
    '#title' => 'Instrument Type',
    '#options' => $options_first,
    '#default_value' => $selected,
    // Bind an ajax callback to the change event (which is the default for the
    // select form type) of the first dropdown. It will replace the second
    // dropdown when rebuilt
    '#ajax' => array(
      // When 'event' occurs, Drupal will perform an ajax request in the
      // background. Usually the default value is sufficient (eg. change for
      // select elements), but valid values include any jQuery event,
      // most notably 'mousedown', 'blur', and 'submit'.
      // 'event' => 'change',
      'callback' => 'ajax_example_dependent_dropdown_callback',
      'wrapper' => 'dropdown-second-replace',
    ),
  );

  $form['dropdown_second'] = array(
    '#type' => 'select',
    '#title' => $options_first[$selected] . ' ' . t('Instruments'),
    // The entire enclosing div created here gets replaced when dropdown_first
    // is changed.
    '#prefix' => '<div id="dropdown-second-replace">',
    '#suffix' => '</div>',
    // when the form is rebuilt during ajax processing, the $selected variable
    // will now have the new value and so the options will change
    '#options' => _ajax_example_get_second_dropdown_options($selected),
    '#default_value' => isset($form_state['values']['dropdown_second']) ? $form_state['values']['dropdown_second'] : '',
  );


  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
  return $form;
}

/**
 * Selects just the second dropdown to be returned for re-rendering
 *
 * Since the controlling logic for populating the form is in the form builder
 * function, all we do here is select the element and return it to be updated.
 *
 * @return renderable array (the second dropdown)
 */
function ajax_example_dependent_dropdown_callback($form, $form_state) {
  return $form['dropdown_second'];
}

/**
 * Helper function to populate the first dropdown. This would normally be
 * pulling data from the database.
 *
 * @return array of options
 */
function _ajax_example_get_first_dropdown_options() {
  // drupal_map_assoc() just makes an array('String' => 'String'...).
  return drupal_map_assoc(array(t('String'), t('Woodwind'), t('Brass'), t('Percussion')));
}

/**
 * Helper function to populate the second dropdown. This would normally be
 * pulling data from the database.
 *
 * @param $key
 *   This will determine which set of options is returned.
 *
 * @return array of options
 */
function _ajax_example_get_second_dropdown_options($key = '') {
  $options = array(
    t('String') => drupal_map_assoc(array(t('Violin'), t('Viola'), t('Cello'), t('Double Bass'))),
    t('Woodwind') => drupal_map_assoc(array(t('Flute'), t('Clarinet'), t('Oboe'), t('Bassoon'))),
    t('Brass') => drupal_map_assoc(array(t('Trumpet'), t('Trombone'), t('French Horn'), t('Euphonium'))),
    t('Percussion') => drupal_map_assoc(array(t('Bass Drum'), t('Timpani'), t('Snare Drum'), t('Tambourine'))),
  );
  if (isset($options[$key])) {
    return $options[$key];
  }
  else {
    return array();
  }
}
/**
 * @} End of "defgroup ajax_example".
 */