Wicket Basic

8/3/2019 Wicket Basic

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Web development

with Java is boring & slow


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NOT TRUE!!!!!!

Welcome Apache Wicket


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About me (wicket specific)

I work @ jayway, a Java specialist house

Contributor on the following Wicketstuff projects: Wicket contrib input events

Wicket contrib Openlayers

Wicket contrib BBCode

Wicket contrib Gmap Wicketstuff minis

Wicketstuff Iolite

More in progress!

Have worked very intensely with wicket for the last 3years

Written several articles / screen casts on misc Wickettopics @ ninomartinez.wordpress.com


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Teaser

EASY (SIMPLE / CONSISTENT / OBVIOUS) POJO-centric

All code written in Java ala Swing

Avoid overuse of XML configuration files

Minimum reliance on special tools

Components, containers and conventions should be consistent

REUSABLE Components written in Wicket should be fully reusable

Reusable components should be easily distributed in ordinary JAR files

NON-INTRUSIVE HTML or other markup not polluted with programming semantics

Compatible with any ordinary HTML editor

SAFE Code is secure by default

Easy to integrate with Java security

EFFICIENT / SCALABLE Efficient and lightweight, but not at the expense of other goals

Clustering through sticky sessions preferred

Clustering via session replication is easy to accomplish.


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Wicket Introduction

Content

When we go over the sections below we are going toimplement a very basic blog application

History

Theory

Web-ApplicationComponents

Behavior & Panel

Markup inheritance

Internationalization (i18n)Forms (input and validation)

Testing

Ajax

Beyond basics

Additional Resources


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History of Wicket

Wicket was conceived in Jonathan Locke's study back in2004, shortly after open sourced at Codehaus, thensourceforge and in 2006 it incubated to a real Apacheproject.

Top level project at Apache today

The name wicket is not the little guy from Star Warsbut a term from cricket meaning a small framework atwhich the bowler aims the ball.


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Theory

Apache Wicket is a object oriented stageful webframework, working with it are just plain java!

Mapping between html tags and wicket components

One .html has one .java (almost always true)

Single threaded(session scope) request cycle asstandard

Sample Code

Java:

Label label=new Label(label,helloworld);

Html:

Result:

hello World


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Theory

Models? Models hold data

is a container

different types (compound,property,detachable, resource)

Sample Code

Java:

Label label=new Label(label,new

Model(new HelloObject()));

Html:

Result:

hello World


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Maven Archetype: Wicket Iolite

mvn archetype:generate-DarchetypeGroupId=org.wicketstuff.iolite

-DarchetypeArtifactId=wicketstuff-iolite

-DarchetypeVersion=0.3-SNAPSHOT

-DarchetypeRepository=http://wicketstuff.org/maven/repository

-DgroupId=com.mycompany-DartifactId=myproject -Dpackage=com.mycompany -Dversion=1

Simple stack archetype Has spring setup for you with JPA and hibernate
http://wicketstuff.org/maven/repositoryhttp://wicketstuff.org/maven/repository


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Demo Setup

What did I doRun archetype generation Domain Logic

Stylesheet

Edited base page, to provide a basic layout

Import project to Eclipse Two module project

Lets create the basic structure for a blog application


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Web-Application

A Wicket web application consists of a class that extends webapplication

a corresponding web.xml which points at the webapplication

some pages

Holds configuration Homepage (default page redirected to)

Session (session object could be used for authentication)

Mounted urls

Spring injection

Lots more can happen here.


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Components

PageLabel

ListView

Link

Wicket Core, Wicket Extensions, WicketstuffIf a component contains children you must add them tothe component, for example a form. Hierarchy is thesame as DOM / HTML


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Code time:)

Let's create a Listview iterating over authors and posts


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Behavior & Panel

Panel, your way to do own componentsBehavior, a way to modify components by adding extrajavascript etc...

MyPanel.html:

MyPanel.java:

public MyPanel(IModel nameModel) {

add(new Label(time,new Model(System.currentTimeMillis()));

add(new Label(name,nameModel));

}


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Markup Inheritance

Wicket supports markup inheritanceWhich means that a page can extend another page

Usage (java side we know using the extends keyword) encapsulate your markup with

Subclass:

Superclass:


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Code time:)

Lets see how it's used in our blog application.


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Internationalization

Resource modelsProperty Files Just use standard java I18n naming of property files

Examples:

myPage.properties

myPage_da.properties

myPage_th.xml

Usage

In page or panel html part

[text]

matching property file:

mykey=mytext


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Forms

Validation Required

More, or roll your own?

Controls Radio

Check

List

Text

Palette

...


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Code time:)

Time for authentication, lets do a Login form on thelogin page

And do the AuthorPage with a form so we can postposts.


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Testing

Wicket provides some simple facilities to make tests Wicket Tester

Simulates Http requests

Allows you to make wicket specific assertions

Wicket FormTester

Allows you to manipulate forms


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Code time:)

Let's examine a test case that tests our LoginPage &AuthorPage flow..


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Ajax

Adding Ajax to wicket is a breeze, just add aajaxBehavior and thats it.

Sometimes though you can use one of the Ajax controlsinstead.

Sample CodeAjaxButton ajaxBtn = newAjaxButton("ajaxButton") {

@Override

protectedvoid onSubmit(AjaxRequestTarget target, Form form){

}@Override

protectedvoid onError(AjaxRequestTarget target, Form form) {

target.addComponent(feedbackPanel);

}

};

d )


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Code time:)

Time to Ajax-ify our home page, let's refresh ourAuthor/post overview at a given interval.

B d B i B t Ni t k


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Beyond Basics, But Nice to know

Authorization Controlling visibility at component level for roles

Protecting against CSRF, withCryptedUrlWebRequestCodingStrategy, set it inWebApplication.java

IVisitor, visit your components. Good for visitingmultiple children and perhaps modifying them, like forexample changing styles based on validation etc.

Additi l R G i f th


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Additional Resources Going further

Wicket In Action (Book)Jayway Wicket Course, 2 days or 3 days

http://cwiki.apache.org/WICKET/

Wicket User Mailinglist [email protected] (very

friendly and helpful community)Maven2 archetypes (fast way to get started ) Quickstart (official), sets up wicket naked..

WicketStuff Iolite (wicketstuff), sets up wicket withJPA(Hibernate) and Spring

http://wicketstuff.org/WUG DK 15 October @ jayway office
mailto:[email protected]://wicketstuff.org/http://wicketstuff.org/mailto:[email protected]

Wicket Basic

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