JavaScript Library Overview

Slide 1: JavaScript Libraries Ajax Experience - October 2007 John Resig (ejohn.org)

Slide 2: Question: How do you want to write JavaScript?

Slide 3: 1) Plug-and-Play • Drop in a “calendar widget” or “tabbed navigation” • Little, to no, JavaScript experience required. • Just customize some options and go. • No flexibility.

Slide 4: 2) Some Assembly Required • Write common utilities • Click a link, load a page via Ajax • Build a dynamic menu • Creating interactive forms • Use pre-made code to distance yourself from browser bugs. • Flexible, until you hit a browser bug.

Slide 5: 3) Down-and-Dirty • Write all JavaScript code from scratch • Deal, directly, with browser bugs • Quirksmode is your lifeline • Excessively flexible, to the point of hinderance.

Slide 6: What we’ve just seen... • Widgets • Libraries • Raw JavaScript

Slide 7: What we’ve just seen... • Widgets • Libraries • Raw JavaScript

Slide 8: Why use a library? • Makes JavaScript bearable • Gets the job done fast • Simplifies cross-browser support • Sort of like C stdlib - no one just codes all of C by hand

Slide 9: What kind of libraries exist? Open Source Commercial Atlas Client/ AjaxCFC Backbase for Server Qcodo Struts Prototype Browser jQuery Backbase Only Yahoo UI SmartClient Dojo

Slide 10: What kind of libraries exist? Open Source Commercial Atlas Client/ AjaxCFC Backbase for Server Qcodo Struts Prototype Browser jQuery Backbase Only Yahoo UI SmartClient Dojo

Slide 11: Open Source Libraries Browser Only Client/Server Scriptaculous Task AjaxCFC moo.fx Specific Qcodo Open Rico Prototype General jQuery Ruby on Rails Purpose Yahoo UI CakePHP Dojo

Slide 12: Open Source Libraries Browser Only Client/Server Scriptaculous Task AjaxCFC moo.fx Specific Qcodo Open Rico Prototype General jQuery Ruby on Rails Purpose Yahoo UI CakePHP Dojo

Slide 13: Why these libraries?

Slide 14: Ajaxian Survey Prototype jQuery Yahoo UI Dojo 20% 35% 21% 25% http://ajaxian.com/archives/ajaxian-2007-survey-results

Slide 15: Google Trends Prototype jQuery Dojo Yahoo UI http://google.com/trends?q=prototype+javascript%2C+jquery+javascript%2C+yui+javascript%2C+dojo+javascript&ctab=0&geo=all&date=all&sort=0

Slide 16: The Libraries

Slide 17: Prototype

Slide 18: Prototype: Overview • Started early 2005 by Sam Stephenson • Incredibly popular, tied with Ruby on Rails’ popularity • Development backed by 37 Signals

Slide 19: Prototype: Focus • Improving the usability of the JavaScript language • Big emphasis on adding in ‘missing’ JavaScript features • Clean structure, clean objects and ‘classes’

Slide 20: Prototype: Details • Code quality is fantastic, great features • All animations (and interactions) are in Scriptaculous • Updated frequently • Looking at Prototype 1.6.0

Slide 21: jQuery

Slide 22: jQuery: Overview • Released January 2006 by John Resig • Rapid rise in popularity • Many developers across the globe

Slide 23: jQuery: Focus • Improving the interaction between JavaScript and HTML • Finding elements then performing actions • Highly-effective, short, code

Slide 24: jQuery: Details • Core features are limited to DOM, Events, Effects, Ajax • Other features can be added in via plugins • Looking at jQuery 1.2.1

Slide 25: Yahoo! UI

Slide 26: YUI: Overview • Released Feb 2006 by Yahoo! • Maintained and financed internally • Attempt to standardize internal JavaScript

Slide 27: YUI: Focus • Exposing, and solving, common methodologies • Looking for common idioms (Drag-and- Drop, Calendar, Auto-Complete) • Looking at Yahoo UI 2.3.1

Slide 28: Dojo

Slide 29: Dojo: Overview • Started early 2005 by Alex Russell + Co. • Large development community • Lots of corporate backing (IBM, AOL) • Big code base, tons of features

Slide 30: Dojo: Focus • Building complete web applications • A package heirarchy, e.g.: dojo.addClass( ... ) • Focus has transcended into widgets (Dijit) • Huge number of features • Today we’re looking at Dojo 0.9

Slide 31: What should a library have?

Slide 32: Code Base • Core Functionality • DOM • Events • Ajax • Animations • User Interface Widgets

Slide 33: Development • Good Architecture • Open Licensing • Wide Browser Support • Small File Size

Slide 34: Project • Development Team (Open, Funded) • Code in SVN / Bug Tracker • Good Unit Test Coverage

Slide 35: Documentation • Full API Coverage • Plenty of Tutorials • Some Books • Wide variety of Demos

Slide 36: Community • Active Mailing List / Forum • Support and Training • Popularity

Slide 37: Code Base • Core Functionality • DOM • Events • Ajax • Animations • User Interface Widgets

Slide 38: Core Functionality • Bare minimum needed to make a dynamic “Ajax” web site: • DOM (Traversal and Manipulation) • Events • Ajax • Animations

Slide 39: DOM • Traversal • Using CSS selectors to locate elements • Modification • Create/remove/modify elements • Having a DOM builder is important

Slide 40: DOM Traversal • Prototype: $$(“table > tr”) • jQuery: $(“div > p:nth-child(odd)”) • Dojo: dojo.query(“table tr:nth-child(even)”) • Yahoo UI: No querying support

Slide 41: DOM Modification • Prototype: Insertion.Bottom(“list”,”<li>Another item</li>”); • jQuery: $(“#li”).append(“<li>An item</li>”); • Dojo and Yahoo UI have weak support - no DOM building capabilities, basic property modification

Slide 42: Events • Support for simple event binding/removal • Support for custom events is essential • Prototype: Event.observe(“button”,”click”, function(){ alert(“Thanks for the click!”); }); • jQuery: $(“div”).click(function(){ alert(“div clicked”); });

Slide 43: Events (cont.) • Yahoo UI: YAHOO.util.Event.addEventListener(“list”, “click”, function(){ alert(“List Clicked”); }); • Dojo: dojo.connect(dojo.byId(\"mylink\"), \"click\", function(){ alert(“Link clicked”); });

Slide 44: Custom Events • $(“#list”).bind(“drag”, function(){ $(this).addClass(“dragged”); }); • $(“#test”).trigger(“drag”);

Slide 45: Ajax • Request and load remote documents • Prototype: new Ajax.Request(“test.html”, { method: “GET”, onComplete: function(res){ $(‘results’).innerHTML = res.responseText; } }); • jQuery: $(“#results”).load(“test.html”);

Slide 46: Ajax (cont.) • Yahoo UI YAHOO.util.Connect.asyncRequest( 'GET', “test.html”, function(data){ YAHOO.util.Dom.id(“results”).innerHTML = data; } ); • Dojo dojo.io.bind({ url: \"test.html\", method: \"get\", mimetype: \"text/html\", load: function(type, data) { dojo.byId(“results”).innerHTML = data; } });

Slide 47: Ajax (cont.) • jQuery is only one capable of doing DOM traversing over XML • jQuery.get(“test.xml”, function(xml){ $(“user”, xml).each(function(){ $(“<li/>”).text( $(this).text() ) .appendTo(“#userlist”); }); });

Slide 48: Animations • Simple animations (hide/show/toggle) • Provide elegant transitions • No animations in Prototype Core (see Scriptaculous, instead) • jQuery: $(“#menu”).slideDown(“slow”);

Slide 49: Animations (cont.) • Yahoo UI: new YAHOO.util.Anim(“list”, { width: { from: 10, to: 100 } }, 1, YAHOO.util.Easing.easeOut ); • Dojo: dojo.fadeOut({ node: dojo.byId(“list”), duration: 500 });

Slide 50: Core Feature Summary DOM Events Anim. Ajax Prototype X X - X jQuery X X X X Yahoo UI / X X X Dojo / X X X

Slide 51: User Interface Widgets • ejohn.org <-- slides • Difficult to implement components, made easy • Commonly used, save duplication • Some common components: Drag & Drop, Tree, Grid, Modal Dialog, Tabbed Pane, Menu / Toolbar, Datepicker, Slider

Slide 52: User Interface Packages • Only looking at officially-supported code: • Prototype has Scriptaculous • jQuery has jQuery UI • Dojo has Dijit • Included in Yahoo UI

Slide 53: Drag & Drop • Drag an item from one location and drop in an other • Supported by all libraries

Slide 54: Tree • A navigable hierarchy (like a folder/file explorer) • In Dojo and Yahoo UI

Slide 55: Grid • An advanced table (resizable, editable, easily navigable) • In Dojo and Yahoo UI

Slide 56: Modal Dialog • Display confined content (usually drag & droppable) and confirmation dialogs • In Dojo,Yahoo UI, and jQuery

Slide 57: Tabbed Pane • Multiple panes of content navigable by a series of tabs • In Dojo,Yahoo UI, and jQuery

Slide 58: Menu / Toolbar • A list of navigable items (with sub-menus) • In Dojo and Yahoo UI

Slide 59: Datepicker • An input for selecting a date (or a range of dates) • In Dojo,Yahoo UI, and jQuery

Slide 60: Slider • A draggable input for entering a general, numerical, value • In all libraries

Slide 61: Tons More! • Color Picker (Dojo,YUI) • Layout (Dojo,YUI) • Auto Complete (Dojo, Proto,YUI) • Selectables (Proto, jQuery) • Accordion (Dojo, jQuery) • WYSIWYG (Dojo,YUI)

Slide 62: Themeing • A consistent look-and-feel for widgets • jQuery,Yahoo UI, and Dojo provide themeing capabilities • jQuery’s and Yahoo UI’s are documented

Slide 63: Accessibility • Taking in to consideration points from ARIA (Accessible Rich Internet Applications) • Dojo is taking a solid lead, here

Slide 64: Development • Good Architecture • Open Licensing • Wide Browser Support • Small File Size

Slide 65: Architecture • Bottom Up (Prototype, jQuery) vs. Top Down (Dojo,Yahoo UI) • jQuery, Dojo, and Yahoo UI all use a single namespace • Prototype extends native objects (high likelihood of inter-library conflict) • jQuery is extensible with plugins

Slide 66: Licensing • All use liberal licenses (“Keep my name on the file, don’t sue me.”) • MIT: Prototype, jQuery • BSD: Yahoo UI, Dojo

Slide 67: Browser Support • Everyone supports: IE 6+, Firefox 2+, Safari 2+, Opera 9+ • Except: • Prototype doesn’t support Opera • Dojo is dropping support for Safari 2

Slide 68: File Size • Serving your JavaScript minified + Gzipped • Optimal level of compression and speed • Core file size (in KB): 35.00 26.25 17.50 8.75 0 Prototype jQuery Yahoo UI Dojo

Slide 69: Project • Development Team (Open, Funded) • Code in SVN / Bug Tracker • Good Unit Test Coverage

Slide 70: Development Team • Prototype, jQuery, and Dojo all have open development (anyone can contribute) • jQuery,Yahoo UI, and Dojo all have paid, full-time, developers working on the code • All have paid, part-time, developers

Slide 71: SVN / Bug Tracker • Prototype, jQuery, and Dojo all have code in a public SVN repositor • Yahoo UI’s development is private and is limited to Yahoo employees • All libraries have a public bug tracker

Slide 72: Unit Tests • All libraries have some automated unit tests • jQuery,Yahoo UI, and Dojo all have public unit tests • jQuery and Dojo have tests that can run in Rhino

Slide 73: Documentation • Full API Coverage • Plenty of Tutorials • Some Books • Wide variety of Demos

Slide 74: API Documentation • Prototype, jQuery, and Yahoo UI all have full coverage • jQuery provides runnable examples with each API item • Dojo’s coverage is spotty - work in progress

Slide 75: Tutorials • All libraries provide some tutorials • jQuery and Yahoo UI have screencasts • Prototype: 6 • jQuery: 68 (English) • Yahoo UI: 32 • Dojo: 5

Slide 76: Books • Prototype: • Prototype and Scriptaculous in Action (Manning) • Prototype and Scriptaculous (Pragmatic) • jQuery: • Learning jQuery (Packt) • jQuery Reference Guide (Packt) • Yahoo UI: None • Dojo: A short online book

Slide 77: Demos • Yahoo UI provides a considerable number of live demos and examples for all features • jQuery provides live examples and a few demo applications • Dojo provides demo applications for their widgets

Slide 78: Community • Active Mailing List / Forum • Support and Training • Popularity

Slide 79: Mailing List / Forum • Prototype, jQuery, and Yahoo UI have mailing lists • Prototype: 23 posts/day • jQuery: 108 posts/day • Yahoo UI: 36 posts/day • Dojo has an active forum

Slide 80: Support and Training • Dojo provides paid support and training (via Sitepen)

Slide 81: Popularity • Who uses what: • Prototype: Apple, ESPN, CNN, Fox News • jQuery: Google, Amazon, Digg, NBC, Intel • Yahoo:Yahoo, LinkedIn, Target, Slashdot • Dojo: IBM, AOL, Mapquest, Bloglines

Slide 82: More Information • Prototype: http://prototypejs.org/ • jQuery: http://jquery.com/ • Yahoo UI: http://developer.yahoo.com/yui/ • Dojo: http://dojotoolkit.org/

Slide 83: Ajax Experience Presentations • Presentations on: • Dojo (2) • Prototype (2) & Scriptaculous (1) • jQuery (3) • Go to one that sounds interesting and enjoy!