The Eclipse news section on the main page has a pointer to the Eclipse Live book @ sourcebeat!

Very Cool!

This example will show you how to conditionally render a UIComponent based on the users role.

Last week during the JSF Book promo on JavaRanch someone asked about this. I promised to put together a quick demo and here it is...

Stuff about this example...

• The Page object creates the conditionally rendered component. This was the only way that I could figure out to make it work. If you can think of another please let me know. I spent some time trying to use an expression but there was no way to tell the value I was getting which component was asking if it should render.
• This simple example uses the Tomcat memory realm instead of a db. For real apps you would want to use a DB realm.
• The login and login-error pages are really simple.
• The test for the page uses mock objects of FacesContext and ExternalContext classes. Quick overview here by Vincent Massol. The latest version of the class mocker (instead of just interfaces) is now at 2.1 but the one included with this download is functional.

Here is the important code in case you don't want to download the example.

JSP Code

     <h:inputText id="test" binding="#{page.inputField}"/>

The binding attribute binds the actual component to a UIComponent created by the object tied to 'page'. IOW when the view is being rendered it will get the component by calling 'getInputField()' on the page object.

Java Code

  public UIInput getInputField() {
    if (authorized()) {
      inputField.setRendered(true);
    } else {
      inputField.setRendered(false);
    }
    return inputField;
  }
  
  private boolean authorized() {
    boolean authorized = false;
    // if its null try to find it
    if(null == context) {
      context = FacesContext.getCurrentInstance();
    }
    // should never happen...
    if (null != context) {
      // clearly 'foo' is a made up role your check should be
      // more valid
      authorized = context.getExternalContext().isUserInRole("foo");
    }
    return authorized;
  }

I finally had time last night to update the Architecture of JSF Applications presentation that I'm doing at the No Fluff Just Stuff Symposiums. You can find the code here.

Enjoy!

In converting some more of the code from JSF Beta to JSF 1.0 I ran into another gotcha. Previously if I had form fields with nothing in them they would leave the values of the managed beans null. In the 1.0 release they set the values to the empty string (i.e. value.length() == 0). No big deal but my example would not work anymore because it relied on null's.

I just finished updating all the code for Mastering JavaServer Faces. Apart from the camelCase that I posted about already there were not very many changes to the code.

The custom component chapter though had one gotcha. Since I had a component I had to register that in the faces-config.xml file like this

  <component>
    <component-type>Scroller</component-type>
    <component-class>calendar.component.UIScroller</component-class>
  </component>
  
  <render-kit>
    <renderer>
      <renderer-type>ScrollerRenderer</renderer-type>
      <renderer-class>calendar.renderer.ScrollerRenderer</renderer-class>
    </renderer>
  </render-kit>

I was getting errors like this;

I found this thread that discussed some other occurrences of similar errors but I'd already been bitten by the old versions of the jars and fixed that in early chapters. Anyway turns out I'm missing the component-family element from my renderer declaration in the faces-config.xml.

  <component>
    <component-type>Scroller</component-type>
    <component-class>calendar.component.UIScroller</component-class>
  </component>
  
  <render-kit>
    <renderer>
     <component-family<Scroller</component-family>
      <renderer-type>ScrollerRenderer</renderer-type>
      <renderer-class>calendar.renderer.ScrollerRenderer</renderer-class>
    </renderer>
  </render-kit>

Adding the componet-family did the trick!

I had a question about SCWCD on the JavaRanch JSF Book Promo about what book to buy for the cert, here is my reply.

What are your thoughts?

Well I finally finished the JSF book, with the final release of the spec I was concerned that I'd have a lot to change but thankfully the only big thing I had to do was update to camelCase. There were lots of little things but over all not bad and I'm finally finished!

In case you have not heard the JSF 1.0 shipped today!

The great folks over at JavaRanch are running a promo of the JSF book here. Looking forward to meeting you online in the forums.

I finally submitted the last of the Mastering JSF book today to Wiley! Boy is that a huge relief. I can't wait to see it on the shelves. It has been a long hard road for this book. After the beta version of the spec shipped 2 days before the book was due to be printed... Then a mad scramble to rewrite a lot of the book. Now I can finally get around to updating the JSF presentation. I'll post again when that is done.