My talk at COmm

1. Rich Web Applications With
mats@bryntum.com
@bryntum

2. Agenda
• Who am I?
• What is Ext JS?
• When (not) to use Ext JS
• Ext Class system
• Widgets, Grids, Forms, Trees
• Dealing with data
• Extending Ext JS classes

3. Before we start
#comday

4. Mats Bryntse
o 35+ yrs old
o From Helsingborg, Sweden
o Background:
o Worked 7 years as SW consultant: C#, ASP.NET, C
o Found Ext JS in 2007, never looked back
o Started Bryntum 2009, http://bryntum.com
o I create JS components & test tools for Ext
JS.
o Twitter: @bryntum

5. What is Ext JS?
Ext JS is a client-side
JavaScript framework
for building rich web
applications.

6. Who has heard of Ext JS
before?

7. Ext JS background &
facts
• Began as YUI-Ext in 2006, 1.0 in 2007, now
v4.1.
• Company called Sencha, based in Palo Alto
• Funded by Sequoia Capital (Google, Yahoo!, Paypal, YouTube)
• Community Forum >300k members

8. Ext JS features
• Full UI application development suite
• Powerful & extensible widgets:
grids, forms, trees, charts
• Data package, class system, MVC, Ext Designer
• Familiar Windows-like look & feel, layout engine

9. When to use Ext JS
• Write web applications not web sites
• Typically LOB applications, intranet apps etc.
• Data intensive apps, gathering, displaying, filtering

10. When not to use Ext JS
• Write web sites
• Write sites or apps targeting mobile/tablet.
Instead use Sencha Touch or jQuery Mobile
• If SEO matters
• If initial page load time is critical

11. Traditional web dev pain points
• Too much time spent defining the user interface
• Browsers quirks => need hacks => uncertainty
• Multiple authors of UI code
=> inconsistent look & feel.
=> easy to end up with function soup
• JS/UI unit testing often an afterthought
• Sounds familiar?

12. Benefits of using Ext JS
• Simple, config-driven, standardized API
• X-browser support, incl. our favorite IE6
• Spend time writing business logic, not HTML tags or
complex CSS layouts.
• Less time spent chasing X-browser bugs

13. Hello World in Firebug

14. JavaScript centric
• Ext JS is all about OOP in JavaScript
• Only basic HTML/CSS skills required
• The Hello World oneliner:
• Generated 50+ DOM nodes.
• No time was spent developing the user interface
• A typical Ext JS application uses a single HTML page
(SPI)

15. Ext JS Widgets

16. Ext JS Widgets
• About 80 examples come with the Ext JS SDK
• Try them yourself: http://dev.sencha.com/deploy/dev/examples/
• All widgets share a uniform API
• Any widget can be extended, features added.

17. Ext JS Grid Panel

18. Ext JS Grid Panel
"...that grid is badass! It does everything.
It cooks you dinner. It washes your car.
It starches your shirts"
reddit.com

19. Ext JS Grid Panel
• Powerful and flexible table component
• Arguably the #1 reason people decide to use Ext JS
(was for me)
• Out of the box: sorting, column resizing, column
reordering, row drag drop, grouping, editing etc...
• Numerous extensions and plugins available

20. Ext JS Grid Panel
Note to self: Demo gridpanel

21. Ext JS Forms

22. Ext JS Forms
• Great for editing and entering data
• Available field types: text, password, number, file
upload, text area, checkbox, radio, date, time.
• Form fields can use vtypes, to validate their value.
alpha, alphanum, email, url
• Validation support on the entire form or individual
fields.

23. Composite Fields

24. Form validation
form.isValid(); // false

25. Ext JS Forms
• Flexible validation error messages
• Individual, side
• Error summary

26. Ext JS Tree Panel

27. Ext JS Tree Panel
• Great for displaying hierarchical data, backed by an
Ext.data.TreeStore
• Supports animation, checkbox selection model, node
reordering
• Also supports the features of GridPanel, column resize,
reorder, hide/show, sorting etc.

28. Ext JS Charts

29. Ext JS Charts
• New in Ext JS 4 (used to rely on YUI flash charts)
• Interactive X-browser charting package
• Falls back to VML for (IE6/IE7/IE8)
• Canvas support coming
• Rich interactivity, click, tooltips, animations

30. Charts Demo

31. Ext JS Class System

32. Ext JS Class System
• Uniform way of defining classes and inheritance
• Classes are defined as strings, meaning file load
order does not matter.
• Mixins allow you to define reusable behavior that can
be applied to multiple classes, achieving multiple
inheritance
• Dynamic class loading via Ext.Loader

33. Defining a simple class
Ext.define(’MyWindowClass’, {
requires : [’SomeOtherClass’, ...],
mixins : [’Draggable’ ],
myMethod : function() { ... }
});

34. Sample Ext Classes

35. Dynamic Loading
• Dynamic class loading via Ext.Loader
• Great for development and debugging purposes
• Use JSBuilder to build xx-all.js file
• Switch to combined and minified xx-all.js file for
production.

36. Classic JS app, week 1
<html>
<head>
<title>My App</title>
<link href="style.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="class1.js"></script>
<script type="text/javascript" src="class2.js"></script>
<script type="text/javascript" src="app.js"></script>
</head>
<body>
</body>
</html>

37. Classic JS app, week 5
<html>
<head>
<title>My App</title>
<link href="style.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="class1.js"></script>
<script type="text/javascript" src="class2.js"></script>
<script type="text/javascript" src="class3.js"></script>
<script type="text/javascript" src="class4.js"></script>
<script type="text/javascript" src="class5.js"></script>
<script type="text/javascript" src="class6.js"></script>
...
<script type="text/javascript" src="class23.js"></script>
<script type="text/javascript" src="app.js"></script>
</head>
<body> </body>
</html>

38. Ext JS DataPackage

39. Benefits of Ext JS data package
• Uniform way of loading and writing data
• All UI components displaying data use stores and models
• UI components have no inherent knowledge about the
data they display – clean separation of concerns

40. DataReader & Proxy
• Ext.data.Reader is used to parse data into a Model
instance or into a Store, typically in response to an
AJAX request.
• Built-in support for JSON and XML and arrays
• Proxies fetch raw, unformatted data from different
types of sources. (HttpProxy, MemoryProxy, JSONP)

41. Model & Store
• A Model is a client side data model which encapsulates
data corresponding to a single DB record
• A Model usually belongs to a Store and has a number of
fields (e.g. )
• A Store encapsulates a client side cache of Model
objects. Provides input data for GridPanel, ComboBox
• Store supports filtering, grouping, sorting etc.

42. Ext JS DataPackage

43. Complex App Using Stores
http://dev.sencha.com/dep
loy/ext-4.0.7-
gpl/examples/sandbox/san
dbox.html

44. Review: Web Desktop
• Again, built a powerful web app simulating a desktop
interface
• No time spent inventing advanced CSS layouts.
• Drawback: We are tricking the user to think it is a real
desktop. Might be disappointed if app behaves different
than the native OS. (Ctrl-Z, Ctrl-S, etc.)

45. Ext JS Component Model

46. Component Model
• Ext.Component is the base class for all Ext components
• Example components:
Ext.form.TextField
Ext.TreePanel
Ext.GridPanel
Ext.Window
• Managed life cycle, template method hooks
• constructor
• initComponent
• onRender
• afterRender
• onDestroy

47. Component Plugins
• Ext Components can be augmented by plugins
• A plugin is any object with an init fn
• The host component calls init during its initialization,
passing itself as the only reference

48. Component Plugins
• Example plugins:
• Ext.grid.CellEditing
• Ext.grid.RowEditing
• Ext.grid.HeaderReorderer
• Ext.grid.HeaderResizer
• Very neat and easy way of breaking out behavior into its
own class

49. Defining a plugin
var myAwesomePlugin = {
init : function(component) {
// Do awesome stuff
}
};

50. Using a plugin
Ext.create(’Ext.GridPanel’, {
width : 500,
height : 500,
store : someDataStore,
plugins: [new Ext.grid.CellEditing()]
});

51. Containers - Layout
• Containers can contain child components
• Choose from several built in layouts to produce complex
layout structures. Nest as deep as you want.
• Example: Complex layout

52. Extending Components
• Very simple to extend existing components
• Add your own custom features and functionality
• Benefit from the Ext Component
lifecycle, managed instantiation and destruction
• Bryntum Gantt chart extends Ext.TreePanel

53. Extending Components
Ext.define(’My.GanttChart’, {
extend : ’Ext.GridPanel’,
requires : [’My.TaskStore’],
initComponent: function() {
// Do stuff...
this.callParent(arguments);
},
renderBars : function() { ... }
});

54. Custom Components
• Forum has a UX section for community extensions
• http://market.sencha.com
• Share, buy or sell your extensions

55. Popular Components

56. Community Extensions
• Example: Interactive SVG map

57. So, Ext JS sounds
great, is there a catch?
• Slight learning curve, reason: big API.
• ext-all-debug.js : 2.3Mb
• jquery1.7.1.js : 240kb
• Helps if you know basic, JS/HTML/CSS

58. Unit Testing Ext apps
• Jasmine
• Selenium (tricky)
• Siesta
• PhantomJS (headless WebKit)

59. Additional Resources
• http://www.sencha.com/learn
• http://www.sencha.com/docs
• http://docs.sencha.com/ext-js/4-0/#!/guide
• http://www.sencha.com/forum/

60. Ext JS and JavaScript training
• Starting spring 2012 together with Informator
• For beginners or intermediate JS developers
• 1-3 days customized to your needs

61. Questions?
mats@bryntum.com
@bryntum