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JavaScript LibrariesAjax Experience - October 2007
John Resig (ejohn.org)
Question: How do you want to write JavaScript?
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.
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.
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.
What we’ve just seen...
• Widgets
• Libraries
• Raw JavaScript
What we’ve just seen...
• Widgets
• Libraries
• Raw JavaScript
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 C by hand
What kind of libraries exist?Open Source Commercial
Client/ Server
AjaxCFCQcodo
AtlasBackbase for
Struts
Browser Only
PrototypeDojo
jQueryYahoo UI
BackbaseSmartClient
What kind of libraries exist?Open Source Commercial
Client/ Server
AjaxCFCQcodo
AtlasBackbase for
Struts
Browser Only
PrototypeDojo
jQueryYahoo UI
BackbaseSmartClient
Open Source LibrariesBrowser Only Client/Server
Task Specific
Scriptaculousmoo.fx
Open Rico
AjaxCFCQcodo
General Purpose
PrototypeDojo
jQueryYahoo UI
Ruby on RailsCakePHP
Open Source LibrariesBrowser Only Client/Server
Task Specific
Scriptaculousmoo.fx
Open Rico
AjaxCFCQcodo
General Purpose
PrototypeDojo
jQueryYahoo UI
Ruby on RailsCakePHP
Why these libraries?
Ajaxian Survey
35%
25%
21%
20%
Prototype jQuery Yahoo UI Dojo
http://ajaxian.com/archives/ajaxian-2007-survey-results
Google Trends
jQuery
Prototype
DojoYahoo 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
The Libraries
Prototype
Prototype: Overview
• Started early 2005 by Sam Stephenson
• Incredibly popular, tied with Ruby on Rails’ popularity
• Development backed by 37 Signals
Prototype: Focus
• Improving the usability of the JavaScript language
• Big emphasis on adding in ‘missing’ JavaScript features
• Clean structure, clean objects and ‘classes’
Prototype: Details
• Code quality is fantastic, great features
• All animations (and interactions) are in Scriptaculous
• Updated frequently
Prototype: Docs & Community
• Documentation: GoodOfficial API documentation, some tutorials
• Community: DistributedMany bloggers love Prototype, little centralized discussion (23 posts/day).
Prototype: File Size & Popularity
• File Size: Moderate (99KB)Unfortunately, not easily compressible with Packer - they recommend GZIP.
• Popularity: StrongApple, ESPN, CNN, Fox News
jQuery
jQuery: Overview
• Released January 2006 by John Resig
• Rapid rise in popularity
• Many developers across the globe
jQuery: Focus
• Improving the interaction between JavaScript and HTML
• Finding elements then performing actions
• Highly-effective, short, code
jQuery: Details
• Core features are limited to DOM, Events, Effects, Ajax
• Other features can be added in via plugins
jQuery: Docs & Community
• Documentation: CompleteFully documented, complete API.
• Community: Vibrant108+ Mailing List Posts/Day
jQuery: File Size & Popularity
• File Size: SmallAbout 20KB with everything.
• Popularity: StrongUsers: IBM, Technorati, MSNBC, DiggProjects: Drupal, Wordpress
Yahoo! UI
YUI: Overview
• Released Feb 2006 by Yahoo!
• Maintained and financed internally
• Attempt to standardize internal JavaScript
YUI: Focus
• Exposing, and solving, common methodologies
• Looking for common idioms (Drag-and-Drop, Calendar, Auto-Complete)
YUI: Details
• Namespaces can become quite verbose. It is recommended that you copy namespaces to other variables.var dom = YAHOO.util.Dom;
• Closed development (Yahoo employees only, no subversion repository)
YUI: Docs & Community
• Documentation: ExcellentEverything is thoroughly documented. Lots of explanations, plenty of demos.
• Community: ModerateMailing List hovering around 36 posts/day.
YUI: File Size & Popularity
• File Size: 40KB (Compressed)Code is quite modular, you can remove un-used code easily.
• Popularity: Possibly WaningMany good bloggers use to talk about it - have moved on.
Dojo
Dojo: Overview
• Started early 2005 by Alex Russell
• Large development community
• Lots of corporate backing (IBM, AOL)
• Big code base, tons of features
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
Dojo: Docs & Community
• Documentation: Rough.In the middle of a major documentation overhaul for 0.9.
• Community: LivelyActive forum with frequent discussions.
Dojo: File Size & Popularity
• File Size: Large (100Kb compressed)It’s highly recommended that you remove unused modules.
• Popularity: SubstantialBacking from many corporate sponsors (IBM).
What should a library have?
Code Base
• Core Functionality
• DOM
• Events
• Ajax
• Animations
• User Interface Widgets
Development
• Good Architecture
• Open Licensing
• Wide Browser Support
• Small File Size
Project
• Development Team (Open, Funded)
• Code in SVN / Bug Tracker
• Good Unit Test Coverage
Documentation
• Full API Coverage
• Plenty of Tutorials
• Some Books
• Wide variety of Demos
Community
• Active Mailing List / Forum
• Support and Training
• Popularity
Code Base
• Core Functionality
• DOM
• Events
• Ajax
• Animations
• User Interface Widgets
Core Functionality
• Bare minimum needed to make a dynamic “Ajax” web site:
• DOM (Traversal and Manipulation)
• Events
• Ajax
• Animations
DOM
• Traversal
• Using CSS selectors to locate elements
• Modification
• Create/remove/modify elements
• Having a DOM builder is important
DOM Traversal
• Prototype:$$(“table > tr”)
• jQuery:$(“div > p:nth-child(odd)”)
• Dojo:dojo.query(“table tr:nth-child(even)”)
• Yahoo UI:No querying support
DOM Modification
• Prototype:Insertion.Bottom(“list”,”<li>Another item</li>”);
• jQuery:$(“#li”).append(“<li>An item</li>”);
• Dojo and Yahoo UI have weak support - no DOM building capabilities, basic property modification
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”);});
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”);});
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”);
Ajax (cont.)• Yahoo UI
YAHOO.util.Connect.asyncRequest( 'GET', “test.html”, function(data){ YAHOO.util.Dom.id(“results”).innerHTML = data; });
• Dojodojo.io.bind({ url: "test.html", method: "get", mimetype: "text/html", load: function(type, data) { dojo.byId(“results”).innerHTML = data; }});
Animations
• Simple animations (hide/show/toggle)
• Provide elegant transitions
• No animations in Prototype Core (see Scriptaculous, instead)
• jQuery:$(“#menu”).slideDown(“slow”);
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 });
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
User Interface Widgets
• 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
User Interface Packages
• Only looking at officially-supported code:
• Prototype has Scriptaculous
• jQuery has jQuery UI
• Dojo has Dijit
• Included in Yahoo UI
Drag & Drop
• Drag an item from one location and drop in an other
• Supported by all libraries
Tree
• A navigable hierarchy (like a folder/file explorer)
• In Dojo and Yahoo UI
Grid
• An advanced table (resizable, editable, easily navigable)
• In Dojo and Yahoo UI
Modal Dialog
• Display confined content (usually drag & droppable) and confirmation dialogs
• In Dojo, Yahoo UI, and jQuery
Tabbed Pane
• Multiple panes of content navigable by a series of tabs
• In Dojo, Yahoo UI, and jQuery
Menu / Toolbar
• A list of navigable items (with sub-menus)
• In Dojo and Yahoo UI
Datepicker
• An input for selecting a date (or a range of dates)
• In Dojo, Yahoo UI, and jQuery
Slider
• A draggable input for entering a general, numerical, value
• In all libraries
Tons More!
• Color Picker (Dojo, YUI)
• Layout (Dojo, YUI)
• Auto Complete (Dojo, Proto, YUI)
• Selectables (Proto, jQuery)
• Accordion (Dojo, jQuery)
• WYSIWYG (Dojo, YUI)
Themeing
• A consistent look-and-feel for widgets
• jQuery, Yahoo UI, and Dojo provide themeing capabilities
• jQuery’s and Yahoo UI’s are documented
Accessibility
• Taking in to consideration points from ARIA (Accessible Rich Internet Applications)
• Dojo is taking a solid lead, here
Development
• Good Architecture
• Open Licensing
• Wide Browser Support
• Small File Size
Architecture
• Bottom Up (Prototype, jQuery) vs. Top Down (Dojo, Yahoo UI)
• jQuery, Dojo, and Yahoo UI all use a single namespace
• jQuery is extensible with plugins
Licensing
• All use liberal licenses (“Keep my name on the file, don’t sue me.”)
• MIT:Prototype, jQuery
• BSD:Yahoo UI, Dojo
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
File Size
• Serving your JavaScript minified + Gzipped
• Optimal level of compression and speed
• Core file size:
0
8.75
17.50
26.25
35.00
Prototype jQuery Yahoo UI Dojo
Project
• Development Team (Open, Funded)
• Code in SVN / Bug Tracker
• Good Unit Test Coverage
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
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
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
Documentation
• Full API Coverage
• Plenty of Tutorials
• Some Books
• Wide variety of Demos
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
Tutorials
• All libraries provide some tutorials
• jQuery and Yahoo UI have screencasts
• Prototype: 6
• jQuery: 68
• Yahoo UI: X
• Dojo: X
Books• Prototype:
• Prototype and Scriptaculous in Action
• Prototype and Scriptaculous (Pragmatic)
• jQuery:
• Learning jQuery (Packt)
• jQuery Reference Guide (Packt)
• Yahoo UI: None
• Dojo: A short online book
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
Community
• Active Mailing List / Forum
• Support and Training
• Popularity
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
Support and Training
• Dojo provides paid support and training (via Sitepen)
Popularity
• Who uses what:
• Prototype: Apple, ESPN, CNN, Fox News
• jQuery: Google, Amazon, Digg, NBC, Intel
• Yahoo: Yahoo, LinkedIn, Target, Slashdot
• Dojo: IBM, AOL
More Information
• Prototype:http://prototypejs.org/
• jQuery:http://jquery.com/
• Yahoo UI:http://developer.yahoo.com/yui/
• Dojo:http://dojotoolkit.org/
Ajax Experience Presentations
• Presentations on:
• Dojo (2)
• Prototype (2) & Scriptaculous (1)
• jQuery (3)
• Go to one that sounds interesting and enjoy!
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