Comments in JSF

Introduction#

JSF as a markup language, supports comments of some parts of code, but we have be carefully, because if we use a normal HTML comment code like this:

<!-- I want to comment the next button -->
<!--        
   <h:commandButton value="Push" onclick="alert('Hello');" />
-->

It’s possible that it doesn’t has commented anything. This is because JSF process this code as default, even if is commented between tags .

There are two solutions to comment any JSF code

Syntax#

ui:remove JSF code that you want to comment </ui:remove>

Remarks#

You can find more information at Oracle documentation:

ui:remove at oracle.com
SKIP_COMMENTS at facelets.java.net

Use tag ui:remove

We need to use tag <ui:remove> and </ui:remove> between any JSF code that we want to comment it.

<ui:remove>
    <h:outputLabel value="Yeah, I'm really commented" />
</ui:remove>

Of course you need add this xmlns to your header html tag. Check this minimal full example:

<html xmlns="https://www.w3.org/1999/xhtml"
    xmlns:h="https://java.sun.com/jsf/html"
    xmlns:ui="https://java.sun.com/jsf/facelets">
    
    <ui:remove>
        <h:outputLabel value="Yeah, I'm really commented" />
    </ui:remove>
    
</html>

Configure facelets.SKIP_COMMENTS

You must to add to web.xml a configuration tag like this:

<context-param>
    <param-name>facelets.SKIP_COMMENTS</param-name>
    <param-value>true</param-value>
</context-param>

Now you can use normal HTML comments tag 

<!--
    <h:outputLabel value="Yeah, I'm really commented" />
-->

Previuosly full example with facelets.SKIP_COMMENTS configured in web.xml will be:

<html xmlns="https://www.w3.org/1999/xhtml"
    xmlns:h="https://java.sun.com/jsf/html"
    xmlns:ui="https://java.sun.com/jsf/facelets">
    
    <!--
        <h:outputLabel value="Yeah, I'm really commented" />
    -->
    
</html>