JavaScript the Smart Way - Getting Started with jQuery

JavaScript the Smart WayGetting Started with jQuery

Drupal User Group presentation

Introduction to jQuery

• JavaScript / jQuery / AJAX - what’s the difference?– JavaScript is a scripting language that adds

interactivity to web pages– jQuery is a JavaScript Framework– AJAX is a particular type of functionality

• JavaScript is to jQuery as PHP is to Drupal

Introduction to jQuery• What can jQuery do for me?

TABS

AJAX

“FLASH”Y STUFF

Introduction to jQuery• Advantages of jQuery over plain JavaScript

– Simplifies cross-browser issues– You don’t have to write the same code over and

over again

• Advantages of jQuery over other JS frameworks– Very concise code– Small file size– completely open source– Plugin architecture

jQuery Basics• What do I need to get started?

– An understanding of CSS and the DOM– Basic understanding of JS syntax (ideally!)– jQuery itself

http://docs.jquery.com/Downloading_jQuery• $(document).ready(function(){

//let’s get started!});

Selectors• CSS$(‘a’), $(‘#container’), $(‘div.ajaxContainer’),$(‘li:first-child’)

• X-Path:$(‘a[title]’), $(‘div[ul]’),$(‘a[href^=“mailto:”]’)

• Custom:$(‘li:eq(1)’),$(‘tr:not([th]):odd’)

Some Useful Methods

• DOM Traversal– .parent(), .siblings(), .next()

• Manipulation– .html(), .empty(), .append(content)

• Events– .ready(fn), .hover(fn1, fn2), .click(fn)

• Effects– .slideToggle(), .show(), .hide()

Chaining

• $(‘#someElement’).parent().parent().find(‘div.green’).hide().end().siblings().find(‘div.blue’).show().end().parent().next().addClass(‘redBorder’);

Show/Hide Example

$(document).ready(function() { $('a.showhide').click(function() {

$(this).parent().parent() .find('div.view-data-body') .slideToggle();

return false; });}); see example

jQuery in Drupal• drupal_add_js($data, $type)

– Add a JavaScript file, setting or inline code to the page, for example:

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

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

• Where do I put my code?– themers: put your .js file in your theme directory and call

drupal_add_js(drupal_get_path(‘theme’, ‘mytheme’) . ‘myjs.js’) from a tpl file

– module developers: put your .js file in your module directory and call drupal_add_js() before you output content

Ajaxifying Drupal with jQuery

• Basic essentials:– jQuery’s .ajax() or .get() method– drupal/path– callback function

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

equivalent.• Drupal.parseJSON(data)

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Ajaxifying Drupal with jQuery

Ajaxifying Drupal with jQuery

‣$items[] = array('path' => 'ajax/path', 'type' => MENU_CALLBACK, 'access' => TRUE, 'callback' => 'get_ajax_image');‣function get_ajax_image($nid) { //some code to retrieve the image print drupal_to_js(array( ‘title’ => $image_title, ‘path’ => $image_path ));}

Ajaxifying Drupal with jQuery

‣ $(‘a.ajax-button’).click(function() { $.get(this.href, function(data){ var result = Drupal.parseJSON(data); $('div.title').html(result['title']); $('div.image').html(result['path']); }); return false;});

Resources

• http://jquery.com• Book: Learning jQuery

» PACKT Publishing

• Cheat sheets:» http://colorcharge.com/jquery

• Other online resources» http://www.learningjquery.com» http://15daysofjquery.com» http://visualjquery.com

Quick Tabs

Create blocks of tabbed views!

http://drupal.org/project/quicktabs

Key Takeaways• jQuery is a framework for writing JavaScript• It is extremely concise and therefore easy to

learn• It has a robust and efficient CSS-based

selector mechanism for precise selection of DOM elements

• It is modular, so non-standard features are available as plugins

• AJAX is a piece of cake with jQuery• Drupal ships with jQuery already built in