Looks good to me Xavier. A danger about the example is that it would
probably be easy to be focussed on determining the password strength
rather than how to create a custom component, but then again, the
example by itself is nice, and can't just be found in the examples
projects.
The kind of example I was thinking about for my presentation would
probably try to show off the fact that Wicket components are stateful
and that the component hierarchy is flexible (Al's talk points that
out nicely for instance).
Eelco
On 8/21/07, Xavier Hanin <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I've just begin to work on my presentation on Wicket for JavaZone (I'm
> replacing Eelco), and I'd like to get some feedback about the agenda I
> plan to follow. The description of the talk is the following:
> "In this session, I will show you how you can use Apache Wicket to
> develop web applications with Just Java and Just HTML. I'll talk a bit
> about Wicket's philosophy and why it's developers believe it is
> important to take a novel approach. And then, because only code really
> talks, we'll take a deep dive to look at how to develop some custom,
> reusable components."
>
> Hence here's the agenda I'm considering:
> •Introduction 5 min
> •What is Wicket 10 min
> •Core concepts of Wicket 15 min
> •Developing a custom component 20 min
> •Q&A 10 min
>
> For the two first topic I'll take inspiration from Martjin's
> presentation at TSSJS europe last year, but in a much more condensed
> way to keep enough time to talk about developing custom components
> with real world example and demo.
>
> About the custom components, I think I will only demonstrate one
> example, since 20 minutes is very short. My idea is to demonstrate how
> to create a password field with a password strength indicator, where
> the password strength is computed on the server by an Ajax call when
> the user stop typing (the event will be triggered by a behavior
> inspired by Nathan work in databinder, I don't plan to explain it).
>
> Here's the Java code for the component:
> --------------8<---------------------
> public class PasswordField extends Panel {
> public final static String WEAK = "weak";
> public final static String MEDIUM = "medium";
> public final static String STRONG = "strong";
>
> public PasswordField(String id, IModel/*<String>*/ model) {
> super(id, model);
> PasswordTextField passwordTextField = new
> PasswordTextField("password", model);
> add(passwordTextField);
>
> final Label strength = new Label("strength", "");
> add(strength);
> strength.add(new AttributeModifier("class", true, new Model() {
> public Object getObject() {
> return
> getPasswordStrength((String)PasswordField.this.getModelObject());
> }
> }));
>
> strength.setOutputMarkupId(true);
> passwordTextField.add(new OnKeyPausedAjaxBehavior() {
> protected void onUpdate(AjaxRequestTarget target) {
> target.addComponent(strength);
> }
> });
> }
>
> /**
> * Returns a String representing the strength of a password.
> * <p>
> * The String returned is one of:
> * <ul>
> * <li>[EMAIL PROTECTED] #WEAK}</li>
> * <li>[EMAIL PROTECTED] #MEDIUM}</li>
> * <li>[EMAIL PROTECTED] #STRONG}</li>
> * </ul>
> *
> * @param password the password to evaluate
> * @return a String representing the evaluated password strength
> */
> protected String getPasswordStrength(String password) {
> // this could involve some complex calculation based on a
> dictionary for instance
> // here for simplicity reason we only use the password length
> if (password == null || password.length() <= 3) {
> return WEAK;
> }
> if (password.length() <= 5) {
> return MEDIUM;
> }
> return STRONG;
> }
>
> }
> --------------8<---------------------
>
> And here is the html:
> --------------8<---------------------
> <html>
> <head>
> <wicket:head>
> <wicket:link>
> <link rel="stylesheet" type="text/css"
> href="PasswordField.css"/>
> </wicket:link>
> </wicket:head>
> </head>
> <body>
> <wicket:panel>
> <input wicket:id="password" type="password" /> <span
> wicket:id="strength"></span>
> </wicket:panel>
> <hr/>
> Examples:<br/>
> <input type="password" /> <span class="weak"></span>
> (weak)<br/>
> <input type="password" /> <span class="medium"></span>
> (medium)<br/>
> <input type="password" /> <span class="strong"></span>
> (strong)<br/>
> </body>
> </html>
> --------------8<---------------------
>
> A css is used to change the background image of the password strength
> meter depending on the span class set by the attribute modifier.
>
> So, what do you think about the agenda? Do you think the time planned
> for each item is well thought? And about the custom component, do you
> think it's a good example? Do you have some suggestions to make for
> the code? Any feedback is appreciated!
>
> Xavier
> --
> Xavier Hanin - Independent Java Consultant
> http://xhab.blogspot.com/
> http://incubator.apache.org/ivy/
> http://www.xoocode.org/
>
