A short (30 minute) introduction to the Apache Wicket web application framework showing its history, uptake and core concepts.

1. Apache Wicket
Web applications with just Java

2. Martijn Dashorst
• Committer
• Chair
• Author

3. Martijn Dashorst
• Committer
• Chair
• Author

4. Agenda
• What is Wicket?
• Wicket concepts
• Wicket roadmap

5. Wicket?

6. Wicket?

7. Wicket
• Component oriented
• Open source
• Web application framework
• Java+HTML

8. Hello, World!

9. Hello, World!

10. Hello, World!
<h1 wicket:id=”msg”>[text goes here]</h1>

11. Hello, World!
<h1 wicket:id=”msg”>[text goes here]</h1>
+
add(new Label(“msg”, “Hello, World!”));

12. Hello, World!
<h1 wicket:id=”msg”>[text goes here]</h1>
+
add(new Label(“msg”, “Hello, World!”));
=
<h1>Hello, World!</h1>

13. A brief history of Wicket

14. • Discovery of the Hobbit
• Year of the monkey
• Milau bridge opens
2004
photo by: 5lab (http://flickr.com/photos/5lab/382292934/)

16. 2005
• Dr. Who returns
• A380’s maiden flight
• Huygens lands on Titan

17. 2005
• Dr. Who returns
• A380’s maiden flight
• Huygens lands on Titan

18. First Wicket meetup

19. First Wicket meetup

20. First Wicket meetup

21. JavaOne’05

22. JavaOne’05
Tapestry
guy Bald Struts/Shale
guy guy
Wicket
JSF guy WebWork guy
guy

23. JavaOne’05
Wicket 1.0

24. Wicket uptake

25. Wicket uptake
Wicket 1.0
released

26. Wicket uptake
Wicket 1.2
released
Wicket 1.0
released

27. Wicket uptake
Wicket 1.2
released
Wicket 1.0
released
Joined
Apache

28. Wicket uptake
Dice (US) 15
Indeed (US) 85
Monster 29
(world)

29. Popular?
Java Software
Apache Software Foundation
Web frameworks

30. Projects
• core
• extensions
Wicket
Welcome to
Apache Wick
et
Home
With proper
Introduction mark-up/logic
separation, a
makes devel
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et del, and a ref
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onents writte , complex de
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Check the fea bugging and
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ture list .
Read some Wi
cket buzz, so
Getting Star me Wicket blo
Find out why
•
ted gs or Planet
you should us Wicket
e Wicket
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examples in
Examples Take a look
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detail or see
at our live co them and ma
mponent ref
Getting Wick Go and down ny more in live
erence
et load Wicket. action
Components
Wicket is rel
eased under
QuickStart the Apache Lic
ense, Version
2.0.
Commun ity meetings
Documentatio
n
The Wicket co
mmunity is a
Wiki very active co
But for those mmunity. Th
that prefer fac e mailing list
e to face me
Blogs s and the irc
etings, severa
•
channel are
l community proof of that.
Reference members ha
ve organized
Where meetups.
London, The
Vision
date/time
United Kingd
om When
JavaDocs Amsterdam, The first Tuesd
The Netherla
nds ay of every mo
Antwerp, Belgi nth
Nov. 30th, 20
um
Releases 07
Copenhagen JavaPolis'07
, Denmark (dec 12th-14
Wicket 1.3-r th)
Linz/Hagenbe
c to be determi
rg, Austria ned
Wicket 1.2 Stockholm, Sw to be determi
eden ned
Wicket 1.1 Rio de Janeir Januari
o, Brazil
Wicket 1.0 Minneapolis/ to be determi
Seattle, USA
•
ned
Tool suppor to be determi
If you are int ned
t
velocity
erested in att
ending one of
you want to these events
organize such
IDE plugins , please add
a meetup yo yourself to the
urself, add it appropriate
to the comm
News event, or if
unity meetups
Developers page
Apache Wick
Reporting bu et 1.3.0-rc1
gs
is released!
Writing docs
Nov 11, 2007
Building
This release
is the first in
•
a series of rel
ease candidate
s until we fee
l confident to
auth-roles
finalize Wicke
t 1.3. This

31. Getting Wicket
• Everybody gets the
ultimate edition
• Includes sources
• Currently 1.3-rc1
• Or...

32. Use maven
<dependency>
<groupId>org.apache.wicket</groupId>
<artifactId>wicket</artifactId>
<version>1.3.0-rc1</version>
</dependency>

34. Agenda
• What is Wicket?
• Wicket concepts
• Wicket roadmap

35. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

36. Application
• Main entry point for your web application
• Initialization
• Configuration
• Homepage
• Factories

37. Application
• Configured in web.xml:
<filter>
<filter-name>wicket</servlet-name>
<filter-class>
org.apache.wicket.protocol.http.WicketFilter
</filter-class>
<init-param>
<param-name>applicationClassName</param-name>
<param-value>example.MyApplication</param-value>
</init-param>
</filter>

38. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

39. Session
• Abstraction of a user session
• Stores session specific data

40. Session
class MySession extends WebSession {
private ShoppingCart cart;
public ShoppingCart getCart() { … }
public void setCart(ShoppingCart cart) { … }
}
mysession.setCart(new ShoppingCart());
…
ShoppingCart cart = mysession.getCart();
cart.add(quantity, selectedProduct);

41. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

42. RequestCycle
• Encapsulates one request
• Cleans up resources at end
• Can be used as OpenSessionInViewFilter

43. RequestCycle
1. Create request cycle object
2. Decode the request
3. Identify request target (page, component, …)
4. Process event (onClick, onSubmit, …)
5. Respond (page, component, image, pdf, …)
6. Clean up

44. RequestCycle
• Two types of requests:
• Stateful
• Stateless

45. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

46. Component
• encapsulate the programmatic manipulation
of markup
• can receive an event (onClick, onSubmit)
• know how and where to render itself

47. Component
• Ultimate super class wicket.Component
Label ListView
MultiLineLabel Loop
TextField PagingNavigator
PasswordTextField ImageMap
Image Button
Link Ajax…
Tree Sorting, paging repeaters
BookmarkablePageLink Wizard
JasperReports DatePicker

48. Component + Markup
• Component has wicket:id
• Markup has same wicket:id
• Hierarchy must match
<h1 wicket:id=“msg”>Gets replaced</h1>
new Label(“msg”, “Hello, World!”);

49. Component: Link
<a href=”#” wicket:id=”link”>Click</a>
Link link = new Link(“link”) {
@Override public void onClick() {
// do something
setResponsePage(new NewPage());
}
};

50. Component: AjaxLink
<a href=”#” wicket:id=”link”>Click</a>
someComponent.setOutputMarkupId(true);
AjaxLink link = new AjaxLink(“link”) {
public void onClick(AjaxRequestTarget t) {
// do something
t.addComponent(someComponent);
t.appendJavaScript(“Effects.fade(‘foo’);”);
}
};

51. Component + Markup
• Some components
have own markup file
• Put Java, markup and
supporting files in
same package on class
path

52. A page: Hello, World!

53. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

54. Behaviors
• Plugins for components
• Modify markup

55. Behavior
link.add(new AbstractBehavior() {
public void onComponentTag(
Component component, ComponentTag tag) {
tag.put(“onclick”, “return confirm(‘Are you sure?’);”);
}
});
Output:
<a href=”...” onclick=”return confirm(‘....’);”>...</a>

56. Behaviors
• Change attributes of your component’s
markup
• Add javascript events
• Add Ajax behavior
component.setOutputMarkupId(true);
component.add(
new AjaxSelfUpdatingBehavior(Duration.seconds(5)));

57. Concepts
• Application
• Session
• RequestCycle
• Components
• Behaviors
• Models

58. Models
• Models bind your POJO’s to Wicket
components
PropertyModel
Label
value
(name)
expression
Person
PropertyModel
Label name
value
(zipcode) zipcode
expression
birthdate
PropertyModel
Label
value
(birthdate)
expression

59. Java lazy binding sucks
• Doesn’t update:
new Label(“name”, person.getName())
• Null checks necessary:
new Label(“street”,
person.getAddress().getStreet())

60. Models
• PropertyModel:
new PropertyModel(p, “name)
new PropertyModel(p, “address.street”)
• CompoundPropertyModel:
setModel(new CompoundPropertyModel(p));
add(new Label(“name”));
add(new Label(“address.street”));

61. Agenda
• What is Wicket?
• Wicket concepts
• Wicket roadmap

62. Roadmap
4/22/07 4/22-4/30 couple of weeks somewhere in june
wicket 1.2.6 wicket 1.2.7
wicket 1.3.0 wicket 1.3.0
wicket 1.3.0 wicket 1.3.1
beta rc
wicket x.y
alpha Jav
a
1.5
ap n
in pro eed
cu v s
ba al
to fro
rP m
M
C

63. Roadmap
• Release 1.3.0 (december)
• Wicket 1.4/2.0
• Java 5!!!!
• first milestone release after 1.3.1-ish

64. Conclusions
• Easy creation and use of custom
components
• Up and coming framework
• Popular
• Great community

65. Questions?