Ed Burns's Blog

(Updated) JavaServer Faces 1.2 and JavaServer Pages 2.1 Proposed Final Draft Specifications available

I'm pleased to announce the availability of the Proposed Final Draft revisions of the next release of the JavaServer^TM Faces and Pages specifications. The Faces spec may be downloaded from <http://www.jcp.org/en/jsr/detail?id=252> and the Pages spec may be downloaded from <http://www.jcp.org/en/jsr/detail?id=245> We really want feedback! Please use our Forum to share your thoughts on the specs. Or you may send feedback to the comments alias for Faces or JSP (jsr-252-comments@jcp.org and jsr-245-comments@jcp.org respectively) .

In this entry, I link to a comprehensive high level outline of the changes to the spec since the 1.1 release of the Faces spec. I've decided include changes present in the December Early Draft Release, the April Public Review Release and the current Proposed Final Draft release for completeness. As such, this entry repeats some information from my blog entry on the April Public Review Release. If you're looking for what's new since that the Public Review release only, please consult this issue tracker query.

Keep in mind this is a high level outline, for details, I encourage you to read the relevant sections of the spec itself.

Before we get to the outline, here is a brief summary of the main changes:

• Unified EL

  The expression language used in Faces, which was inspired by the expression language used in JSTL and JSP, has been generalized and extracted into its own top level javax.el package. The EL is agnostic of the technology hosting it, such as JSP or Faces, and is intended to be generally useful in the same way one can use OGNL in a variety of applications. Faces now has deprecated its internal EL in favor of using the Unified EL.

• New Tree Creation and Content Interweaving Model for Faces applications that use JSP

  While it is perfectly acceptable to use Faces without using JSP, many people find their productivity increases when using these two technologies together. Unfortunately, as amply documented by Hans Bergsten in his article at onjava.com, there were some integration cases that didn't work as expected. By changing the specification of the implementation of the Faces ViewHandler for JSP, as well as changing the JSP custom tag base class used by all Faces component tags, these problems have all been resolved.

• Integration with JSTL

  Another long standing problem was in using JSTL's <c:forEach> tag to contain Faces input components. Because JSP has no notion of a postback, it was not possible to apply the values correctly to the nested input components on postback. By introducing some new concepts into the EL, it is now possible to fully use <c:forEach> with any kind of Faces component. This will require a new release of JSTL, which will also be present in J2EE 5, along with Faces and JSP.

• Back Button issues and Multi Frame or Multi Window Faces Apps

  Due to a deficiency in the State Management API using Faces in Multi Frame or Multi Window applications presented some problems. The browser back button also could cause application state to become confused. These problems have now been fixed.

• Associating a message with a particular component in the page.

  Previous revisions of the spec didn't allow for dynamically including the label of a component in an error message for that component. New spec features now allow for this to happen.

  It is now possible to override the conversion or validation message that is displayed to the user on a per-instance basis. For example:

  
  <h:inputText value="#{bean.value}" 
                  requiredMessage="#{bundle.requiredMessage}"
                  converterMessage="#{bundle.converterMessage}"
                  validatorMessage="#{bundle.requiredMessage}">
    <f:validateLongRange maximum="1" minimum="10"/>
  </h:inputText>
  
  

• AJAX support

  As you should all know by know, AJAX is mainly a component thing, but there are some things the basic JSF framework can do to make things a little easier for those writing AJAXian JSF components. Even without these features (ie, in JSF 1.1), it's very easy to write AJAX components for JSF and easier still to use them.

  Specify that the FacesServlet should look for an init-param called javax.faces.LIFECYCLE_ID to identify the Lifecycle to be used for processing this request. This approach allows you to map different instances of the FacesServlet with different lifecycles. For example, one mapping for standard JSF requests and another for AJAX JSF requests.

  Specify the name of the state saving parameter so that AJAX scripts can manually post back the state to the server using XMLHttpRequest, therefore enabling the AJAX processing code to have access to the full view. This approach was used in the Progress Bar JSF component. The name of the parameter is javax.faces.ViewState.

• Expose an application wide ResourceBundle to the EL.

  We have added a new <resource-bundle> element to the faces-config that allows you to list zero or more resource bundles that should be exposed to the EL using the new ELResolver chain. Doing this allows performance optimizations that prevent the need to create a ResourceBundle for every request.

• API classes use generics

  In response to strong Expert Group demand, we have applied Java SE 5.0 Generics to the JSF api. Therefore, the minimum JDK requirement for JSF 1.2 is Java SE 5.0. I'm told that it's possible to retroweave a binary to make it run under 1.4, but of course that configuration is not supported or recommended by Sun.

All of these features and more are currently available in the JSF implementation found in Sun's Open Source Appserver, glassfish.

Now, the outline of changes is available here.

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Comments

• Ed,

  What about the Java SE requirements? Hasn't it changed to Java SE 5 (a.k.a Tiger)?

  -- Felipe
  

  Posted by: felipeal on August 25, 2005 at 08:31 PM

• Sounds great Ed,

  Can the glassfish JSF implementation be decoupled and used with Tomcat?

  Keep up the great work,

  --John

  Posted by: johnreynolds on August 26, 2005 at 06:23 AM

• Is it possible to pass localized label when associating a message with a particular component in the page?

  Is it possible to localize standard conversion or validation message in single place, as it was in JSF 1.1? See http://www.jsf-faq.com/faqs/faces-messages.html#126 for example.

  Thanks!

  Posted by: avalez on October 28, 2006 at 02:29 PM

• 
  A> Is it possible to pass localized label when associating a message
  A> with a particular component in the page? Is it possible to localize
  A> standard conversion or validation message in single place, as it was
  A> in JSF 1.1? See http://www.jsf-faq.com/faqs/faces-messages.html#126
  A> for example. Thanks!

  
  Yes, the above example from JSF-FAQ.com should still work in JSF 1.2.
  However, in addition, there is another way to do it in a per-component
  manner, as you seem to be requesting. Here's how.

  Know that in JSF 1.2, in addition to the f:loadBundel tag, it is
  possible, and indeed recommended, to declare the supported locales,
  and resource-bundles to go along with them, in the faces-config file.

  Given 1, each component in JSF 1.2 has a validatorMessage and
  converterMessage property that can be set on a per-component basis to
  an arbitrary value from the EL. This value can come from a bundle
  loaded via f:loadBundle, or from one defined at the application level
  from faces-config.

  
  

  Posted by: edburns on October 30, 2006 at 10:42 AM

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