jQuery in Drupal:overview, tools, how-tos

DrupalCamp Vancouver 2008

Introduction

• jQuery is a JavaScript Framework

• In core since Drupal 5 (version 1.0.1)

• Modular, like Drupal itself

• and, like Drupal, constantly evolving...

Overview / Timeline

jQuery Syntax Refresher

• Selectors– $(‘#myId’), $(‘div.myClass’),

$(‘li:not(.active)’), $(‘a[href^=“mailto”]’)

• Commands– .hide(), .show(), .slideToggle(), .each(), etc

• Utility Functions– $.each(), $.get(), $.browser(), $.noConflict()

• Chaining Example$('div.myClass').not(':first-child').hide().end().filter(':first-child').wrap('<div class="my-wrapper"></div>');

Important Functions

• drupal_add_js– Add a JavaScript file, setting or inline code to the

page– parameters: data, type, scope, defer, cache– Examples:

• drupal_add_js(drupal_get_path(‘module’, ‘mymodule’) .'/myjs.js');

• drupal_add_js(array(‘myjs’=>$mysettings), ‘setting’);• Drupal_add_js(‘var myVar = “foo”;’, ‘inline’);

• Use ‘setting’ type to make your module’s settings available to js

Important Functions

• drupal_get_js()– called from phptemplate.engine (assigned

to scripts variable)– makes a call to drupal_add_js() to get the

$javascript array– $output .= '<script type="text/javascript">

Drupal.extend({ settings: '. drupal_to_js(call_user_func_array('array_merge_recursive', $data)) ." });</script>\n";

Important Functions

• drupal_to_js()– Converts a PHP variable into its JavaScript

equivalent– e.g. convert a PHP array into a JSON object– used in the callback function for an AJAX

path

The Drupal JavaScript Object

drupal.js in D5:

var Drupal = Drupal || {};

drupal.js in D6:

var Drupal = Drupal || { 'settings': {}, 'behaviors': {}, 'themes': {}, 'locale': {} };

Ajaxifying Drupal with jQuery

• Asynchronous JavaScript and XML– retrieve data from the server and load into

the DOM of the current page without refreshing the page

– $(‘#someDiv’).load(‘/serverResource’);– the above corresponds to about 20 lines of

normal js

• jQuery provides different AJAX functions, depending on your needs

Ajaxifying Drupal with jQuery

• jQuery AJAX functions:– $(‘#someDiv’).load(url, parameters,

callback);– $.get(url, parameters, callback)– $.post(url, parameters, callback)– $.ajax(options)

11

Ajaxifying Drupal with jQuery

Ajaxifying Drupal with jQuery

• Basic essentials:– $.get (or another AJAX method)– drupal/path (menu callback)– callback function

• drupal_to_js($var)– to convert your php array into a JSON

array

• Drupal.parseJSON(data)

Ajaxifying Drupal with jQuery

Menu Callback

$items[] = array( 'path' => 'photostories/get/photos', 'type' => MENU_CALLBACK, 'access' => user_access('access content'), 'callback' => 'kflick_get_photos_ajax');

Ajaxifying Drupal with jQuery

Callback Function

function kflick_get_photos_ajax($nid) {

$photo = kflick_get_photo($nid);

$imagefile = theme('image', $photo);

print drupal_to_js(array(

'image' => $imagefile,

)

);

}

Ajaxifying Drupal with jQuery

Drupal.kflick = function() { var imageDetails = function(data) {

var result = Drupal.parseJson(data); $('div.field-type-image div.field-item').html(result['image']); } $('a.kflick_button').click(function(){ $('a.kflick_button').removeClass('active'); $(this).addClass('active'); $.get('/photostories/get/photos/'+ parseInt(this.id, 10), null, imageDetails); return false; });}

if (Drupal.jsEnabled) { $(document).ready(Drupal.kflick);}

Drupal 6: behaviors

• In D6, wrap all your module’s jQuery behaviours in a function assigned to Drupal.behaviors.mymodule

• no need to call it within $(document).ready() as Drupal automatically does it for you

• all behaviors can then be reattached to DOM elements that have come from an AJAX call

Drupal 6: behaviors

Drupal.behaviors.kflick = function(context) { $('div.field-type-image:not(.kflick-processed)', context).addClass(‘kflick-processed’).each(function(){ var imageDetails = function(data) {

var result = Drupal.parseJson(data); $('div.field-type-image div.field-item').html(result['image']); } $('a.kflick_button').click(function(){ $('a.kflick_button').removeClass('active'); $(this).addClass('active'); $.get('/drupal/sandbox/photostories/get/photos/'+ parseInt(this.id, 10), null, imageDetails); return false; }); });}

Drupal 6: behaviors

Drupal.attachBehaviors = function(context) { context = context || document; if (Drupal.jsEnabled) { // Execute all of them.

jQuery.each(Drupal.behaviors, function() {

this(context); }); }};

What is AHAH?

• Asynchronous HTML and HTTP• still uses the XMLHttpRequest object• still uses JavaScript• loads html content retrieved from the

server directly into the DOM - no parsing necessary

• AHAH in Drupal = AHAH Forms• AHAH Forms Framework module• In core as of D6

AHAH in Drupal 6

$form['qt_wrapper']['tabs_more'] = array( '#type' => 'submit', '#value' => t('More tabs'), '#description' => t("Click here to add more tabs."), '#weight' => 1, '#submit' => array('qt_more_tabs_submit'), // If no javascript action. '#ahah' => array( 'path' => 'quicktabs/ahah', 'wrapper' => 'quicktabs-tabs', 'method' => 'replace', 'effect' => 'fade', ), );

Drag & Drop

theme('table', $header, $rows, array('id' => 'my-table'));

$row = array(...);$rows[] = array('data' => $row,'class' => 'draggable',);

drupal_add_tabledrag('my-module-table', 'order', 'sibling', 'my-elements-weight');

$form['my_elements'][$delta]['weight']['#attributes']['class'] = "my-elements-weight";

drupal_add_tabledrag($table_id, $action, $relationship, $group);

Resources

• JavaScript Startup Guideon api.drupal.org

• drupaldojo.com/lesson/ahah• http://jquery.com• Firebug console• Books

– Learning jQuery– jQuery in Action