views:

353

answers:

4

Facelets relies on XML namespaces to work with XHTML. How are HTML 4, and as far as I know, HTML 5 do not support namespaces. Also HTML 5 has some new elements that are not available in XHTML. Even HTML 4 and XHTML have some differences regarding elements and attributes they support.

The question is: Is it possible to render HTML 4/5 documents using Facelets? If so, how?

A: 

I've read, that this should be possible, but I did not do it myself, yet. Maybe you should just use HTML 5 inside the xHTML wrapper code. I will see, if I can find the source if information I've again.

[EDIT] Seems like, there has been some work at MyFaces to support HTML5 rendering during Goole's summer of code. I dont know if it should be used in a productive way, yet.

Please give us a feedback, if you get it to work. [/EDIT]

PageFault
A: 

http://wiki.whatwg.org/wiki/HTML_vs._XHTML has some useful information on how namespaces can be used in HTML5 to assist migration from XHTML. Perhaps you can try applying the namespace as it suggests and see what occurs?

karianna
+4  A: 

Since Facelets is a XML based view technology which emits in essence XML markup, you cannot use it with a HTML4 doctype. The HTML4 doctype describes several elements which cannot be self-closing, like <link>, <meta>, <br> and <hr>. However, with XML you're forced to close them like <link/>, <meta/>, etc. So using a HTML4 doctype is absolutely not an option for Facelets (that is, when you respect the standards and/or fear the w3 validator, it will however work perfectly on the most if not all webbrowsers).

HTML5, on the other hand, allows XML markup. This is specified in chapter 3.2.2 - Elements:

Example:

<link type="text/css" href="style.css"/>

Authors may optionally choose to use this same syntax for void elements in the HTML syntax as well. Some authors also choose to include whitespace before the slash, however this is not necessary. (Using whitespace in that fashion is a convention inherited from the compatibility guidelines in XHTML 1.0, Appendix C.)

I myself use <!DOCTYPE html> all the way, also with JSF/Facelets, even without a <?xml?> declaration in top of the page. It works perfectly in all browsers. With a XHTML doctype you should as per the specification be using a Content-Type of application/xhtml+xml which would only make MSIE to choke (it doesn't understand it). And since that's still one of the most widely used browsers... Replacing the XHTML content type by text/html is considered harmful, you also don't want to do this.

As per your arguments:

HTML 5 do not support namespaces.

This doesn't matter. The namespaces are only of interest for the XML based server side view technology (like as Facelets) which in turn can generate pure HTML with those tags. The following example is legitimately valid for Facelets:

<!DOCTYPE html>
<html lang="en"
    xmlns:f="http://java.sun.com/jsf/core" 
    xmlns:h="http://java.sun.com/jsf/html"&gt;
    <h:head>
        <title>Title</title>
    </h:head>
    <h:body>
        <h:outputText value="#{bean.text}" />
    </h:body>
</html>

This renders legitimately valid HTML5 (for the client side):

<!DOCTYPE html>
<html lang="en">
    <head>
        <title>Title</title>
    </head>
    <body>
        Some text
    </body>
</html>

You see, Facelets already removes the XHTML declarations since they have no meaning in the client side.

And,

Also HTML 5 has some new elements that are not available in XHTML

this make also no sense. It's all about the generated output. Which can be HTML5 as good. Your only problem may be the browser support and the availability of 3rd party JSF components which renders HTML5 specific elements.

In my opinion, XHTML is overhyped. Its sole intent is to ease HTML development using XML based tools which can manipulate/transform/generate HTML pages on the server side (like as Facelets). But some people also use it without using any XML tool and output it plain as-is, because it's "so cool" -for some unclear reason. Shrug.

Don't get me wrong. XHTML is great as server side view technology. But simply not as client side markup technology. It has utterly no value at the client side.

See also:

BalusC
XHTML is designed to be compatible with HTML4. It isn't?
Thorbjørn Ravn Andersen
@Thor: [XHTML1 is a "reformulation" of HTML4 as a XML 1.0 application](http://www.w3.org/TR/xhtml1/). As to compatibility, the w3 validator will only issue warnings (not errors) when you close non-self-closing elements while validating against HTML4. It will work without problems on most if not all browsers.
BalusC
In the past couple of days Stackoverflow was unstable and it seems that my previous comment to your answer has been lost as such. Anyway, thanks for the answer.
Bytecode Ninja
+1  A: 

On a related note, check out this IBM developerWorks article: JSF 2 fu: HTML5 composite components, Part 1

vetler
That's a nice article!
BalusC