drupal/core/includes/ajax.inc

343 lines
15 KiB
PHP

<?php
/**
* @file
* Functions for use with Drupal's Ajax framework.
*/
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Element;
/**
* @defgroup ajax Ajax API
* @{
* Overview for Drupal's Ajax API.
*
* @section sec_overview Overview of Ajax
* Ajax is the process of dynamically updating parts of a page's HTML based on
* data from the server. When a specified event takes place, a PHP callback is
* triggered, which performs server-side logic and may return updated markup or
* JavaScript commands to run. After the return, the browser runs the JavaScript
* or updates the markup on the fly, with no full page refresh necessary.
*
* Many different events can trigger Ajax responses, including:
* - Clicking a button
* - Pressing a key
* - Moving the mouse
*
* @section sec_framework Ajax responses in forms
* Forms that use the Drupal Form API (see the
* @link form_api Form API topic @endlink for more information about forms) can
* trigger AJAX responses. Here is an outline of the steps:
* - Add property '#ajax' to a form element in your form array, to trigger an
* Ajax response.
* - Write an Ajax callback to process the input and respond.
* See sections below for details on these two steps.
*
* @subsection sub_form Adding Ajax triggers to a form
* As an example of adding Ajax triggers to a form, consider editing a date
* format, where the user is provided with a sample of the generated date output
* as they type. To accomplish this, typing in the text field should trigger an
* Ajax response. This is done in the text field form array element
* in \Drupal\config_translation\FormElement\DateFormat::getFormElement():
* @code
* '#ajax' => array(
* 'callback' => 'Drupal\config_translation\FormElement\DateFormat::ajaxSample',
* 'event' => 'keyup',
* 'progress' => array(
* 'type' => 'throbber',
* 'message' => NULL,
* ),
* ),
* @endcode
*
* As you can see from this example, the #ajax property for a form element is
* an array. Here are the details of its elements, all of which are optional:
* - callback: The callback to invoke to handle the server side of the
* Ajax event. More information on callbacks is below in @ref sub_callback.
* - path: The URL path to use for the request. If omitted, defaults to
* 'system/ajax', which invokes the default Drupal Ajax processing (this will
* call the callback supplied in the 'callback' element). If you supply a
* path, you must set up a routing entry to handle the request yourself and
* return output described in @ref sub_callback below. See the
* @link menu Routing topic @endlink for more information on routing.
* - wrapper: The HTML 'id' attribute of the area where the content returned by
* the callback should be placed. Note that callbacks have a choice of
* returning content or JavaScript commands; 'wrapper' is used for content
* returns.
* - method: The jQuery method for placing the new content (used with
* 'wrapper'). Valid options are 'replaceWith' (default), 'append', 'prepend',
* 'before', 'after', or 'html'. See
* http://api.jquery.com/category/manipulation/ for more information on these
* methods.
* - effect: The jQuery effect to use when placing the new HTML (used with
* 'wrapper'). Valid options are 'none' (default), 'slide', or 'fade'.
* - speed: The effect speed to use (used with 'effect' and 'wrapper'). Valid
* options are 'slow' (default), 'fast', or the number of milliseconds the
* effect should run.
* - event: The JavaScript event to respond to. This is selected automatically
* for the type of form element; provide a value to override the default.
* - prevent: A JavaScript event to prevent when the event is triggered. For
* example, if you use event 'mousedown' on a button, you might want to
* prevent 'click' events from also being triggered.
* - progress: An array indicating how to show Ajax processing progress. Can
* contain one or more of these elements:
* - type: Type of indicator: 'throbber' (default) or 'bar'.
* - message: Translated message to display.
* - url: For a bar progress indicator, URL path for determining progress.
* - interval: For a bar progress indicator, how often to update it.
*
* @subsection sub_callback Setting up a callback to process Ajax
* Once you have set up your form to trigger an Ajax response (see @ref sub_form
* above), you need to write some PHP code to process the response. If you use
* 'path' in your Ajax set-up, your route controller will be triggered with only
* the information you provide in the URL. If you use 'callback', your callback
* method is a function, which will receive the $form and $form_state from the
* triggering form. You can use $form_state to get information about the
* data the user has entered into the form. For instance, in the above example
* for the date format preview,
* \Drupal\config_translation\FormElement\DateFormat\ajaxSample() does this to
* get the format string entered by the user:
* @code
* $format_value = \Drupal\Component\Utility\NestedArray::getValue(
* $form_state->getValues(),
* $form_state['triggering_element']['#array_parents']);
* @endcode
*
* Once you have processed the input, you have your choice of returning HTML
* markup or a set of Ajax commands. If you choose to return HTML markup, you
* can return it as a string or a renderable array, and it will be placed in
* the defined 'wrapper' element (see documentation above in @ref sub_form).
* In addition, any messages returned by drupal_get_messages(), themed as in
* status-messages.html.twig, will be prepended.
*
* To return commands, you need to set up an object of class
* \Drupal\Core\Ajax\AjaxResponse, and then use its addCommand() method to add
* individual commands to it. In the date format preview example, the format
* output is calculated, and then it is returned as replacement markup for a div
* like this:
* @code
* $response = new AjaxResponse();
* $response->addCommand(new ReplaceCommand(
* '#edit-date-format-suffix',
* '<small id="edit-date-format-suffix">' . $format . '</small>'));
* return $response;
* @endcode
*
* The individual commands that you can return implement interface
* \Drupal\Core\Ajax\CommandInterface. Available commands provide the ability
* to pop up alerts, manipulate text and markup in various ways, redirect
* to a new URL, and the generic \Drupal\Core\Ajax\InvokeCommand, which
* invokes an arbitrary jQuery commnd.
*
* As noted above, status messages are prepended automatically if you use the
* 'wrapper' method and return HTML markup. This is not the case if you return
* commands, but if you would like to show status messages, you can add
* @code
* array('#theme' => 'status_messages')
* @endcode
* to a render array, use drupal_render() to render it, and add a command to
* place the messages in an appropriate location.
*
* @section sec_other Other methods for triggering Ajax
* Here are some additional methods you can use to trigger Ajax responses in
* Drupal:
* - Add class 'use-ajax' to a link. The link will be loaded using an Ajax
* call. When using this method, the href of the link can contain '/nojs/' as
* part of the path. When the Ajax JavaScript processes the page, it will
* convert this to '/ajax/'. The server is then able to easily tell if this
* request was made through an actual Ajax request or in a degraded state, and
* respond appropriately.
* - Add class 'use-ajax-submit' to a submit button in a form. The form will
* then be submitted via Ajax to the path specified in the #action. Like the
* ajax-submit class on links, this path will have '/nojs/' replaced with
* '/ajax/' so that the submit handler can tell if the form was submitted in a
* degraded state or not.
* - Add property '#autocomplete_route_name' to a text field in a form. The
* route controller for this route must return an array of options for
* autocomplete, as a \Symfony\Component\HttpFoundation\JsonResponse object.
* See the @link menu Routing topic @endlink for more information about
* routing.
*/
/**
* Form element processing handler for the #ajax form property.
*
* @deprecated Use \Drupal\Core\Render\Element\FormElement::processAjaxForm().
*/
function ajax_process_form($element, FormStateInterface $form_state, &$complete_form) {
return Element\FormElement::processAjaxForm($element, $form_state, $complete_form);
}
/**
* Adds Ajax information about an element to communicate with JavaScript.
*
* If #ajax['path'] is set on an element, this additional JavaScript is added
* to the page header to attach the Ajax behaviors. See ajax.js for more
* information.
*
* @param $element
* An associative array containing the properties of the element.
* Properties used:
* - #ajax['event']
* - #ajax['prevent']
* - #ajax['path']
* - #ajax['options']
* - #ajax['wrapper']
* - #ajax['parameters']
* - #ajax['effect']
* - #ajax['accepts']
*
* @return
* The processed element with the necessary JavaScript attached to it.
*/
function ajax_pre_render_element($element) {
// Skip already processed elements.
if (isset($element['#ajax_processed'])) {
return $element;
}
// Initialize #ajax_processed, so we do not process this element again.
$element['#ajax_processed'] = FALSE;
// Nothing to do if there are no Ajax settings.
if (empty($element['#ajax'])) {
return $element;
}
// Add a reasonable default event handler if none was specified.
if (isset($element['#ajax']) && !isset($element['#ajax']['event'])) {
switch ($element['#type']) {
case 'submit':
case 'button':
case 'image_button':
// Pressing the ENTER key within a textfield triggers the click event of
// the form's first submit button. Triggering Ajax in this situation
// leads to problems, like breaking autocomplete textfields, so we bind
// to mousedown instead of click.
// @see http://drupal.org/node/216059
$element['#ajax']['event'] = 'mousedown';
// Retain keyboard accessibility by setting 'keypress'. This causes
// ajax.js to trigger 'event' when SPACE or ENTER are pressed while the
// button has focus.
$element['#ajax']['keypress'] = TRUE;
// Binding to mousedown rather than click means that it is possible to
// trigger a click by pressing the mouse, holding the mouse button down
// until the Ajax request is complete and the button is re-enabled, and
// then releasing the mouse button. Set 'prevent' so that ajax.js binds
// an additional handler to prevent such a click from triggering a
// non-Ajax form submission. This also prevents a textfield's ENTER
// press triggering this button's non-Ajax form submission behavior.
if (!isset($element['#ajax']['prevent'])) {
$element['#ajax']['prevent'] = 'click';
}
break;
case 'password':
case 'textfield':
case 'number':
case 'tel':
case 'textarea':
$element['#ajax']['event'] = 'blur';
break;
case 'radio':
case 'checkbox':
case 'select':
$element['#ajax']['event'] = 'change';
break;
case 'link':
$element['#ajax']['event'] = 'click';
break;
default:
return $element;
}
}
// Attach JavaScript settings to the element.
if (isset($element['#ajax']['event'])) {
$element['#attached']['library'][] = 'core/jquery.form';
$element['#attached']['library'][] = 'core/drupal.ajax';
$settings = $element['#ajax'];
// Assign default settings. When 'path' is set to NULL, ajax.js submits the
// Ajax request to the same URL as the form or link destination is for
// someone with JavaScript disabled. This is generally preferred as a way to
// ensure consistent server processing for js and no-js users, and Drupal's
// content negotiation takes care of formatting the response appropriately.
// However, 'path' and 'options' may be set when wanting server processing
// to be substantially different for a JavaScript triggered submission.
// One such substantial difference is form elements that use
// #ajax['callback'] for determining which part of the form needs
// re-rendering. For that, we have a special 'system/ajax' route.
$settings += array(
'path' => isset($settings['callback']) ? 'system/ajax' : NULL,
'options' => array(),
'accepts' => 'application/vnd.drupal-ajax'
);
// @todo Legacy support. Remove in Drupal 8.
if (isset($settings['method']) && $settings['method'] == 'replace') {
$settings['method'] = 'replaceWith';
}
// Change path to URL.
$settings['url'] = isset($settings['path']) ? url($settings['path'], $settings['options']) : NULL;
unset($settings['path'], $settings['options']);
// Add special data to $settings['submit'] so that when this element
// triggers an Ajax submission, Drupal's form processing can determine which
// element triggered it.
// @see _form_element_triggered_scripted_submission()
if (isset($settings['trigger_as'])) {
// An element can add a 'trigger_as' key within #ajax to make the element
// submit as though another one (for example, a non-button can use this
// to submit the form as though a button were clicked). When using this,
// the 'name' key is always required to identify the element to trigger
// as. The 'value' key is optional, and only needed when multiple elements
// share the same name, which is commonly the case for buttons.
$settings['submit']['_triggering_element_name'] = $settings['trigger_as']['name'];
if (isset($settings['trigger_as']['value'])) {
$settings['submit']['_triggering_element_value'] = $settings['trigger_as']['value'];
}
unset($settings['trigger_as']);
}
elseif (isset($element['#name'])) {
// Most of the time, elements can submit as themselves, in which case the
// 'trigger_as' key isn't needed, and the element's name is used.
$settings['submit']['_triggering_element_name'] = $element['#name'];
// If the element is a (non-image) button, its name may not identify it
// uniquely, in which case a match on value is also needed.
// @see _form_button_was_clicked()
if (!empty($element['#is_button']) && empty($element['#has_garbage_value'])) {
$settings['submit']['_triggering_element_value'] = $element['#value'];
}
}
// Convert a simple #ajax['progress'] string into an array.
if (isset($settings['progress']) && is_string($settings['progress'])) {
$settings['progress'] = array('type' => $settings['progress']);
}
// Change progress path to a full URL.
if (isset($settings['progress']['path'])) {
$settings['progress']['url'] = url($settings['progress']['path']);
unset($settings['progress']['path']);
}
$element['#attached']['js'][] = array(
'type' => 'setting',
'data' => array('ajax' => array($element['#id'] => $settings)),
);
// Indicate that Ajax processing was successful.
$element['#ajax_processed'] = TRUE;
}
return $element;
}
/**
* @} End of "defgroup ajax".
*/