Module org.omnifaces
Package org.omnifaces.component.output

Class ConditionalComment

  • All Implemented Interfaces:
    PartialStateHolder, StateHolder, TransientStateHolder, ComponentSystemEventListener, FacesListener, SystemEventListenerHolder, EventListener
    public class ConditionalComment
extends OutputFamily

    The <o:conditionalComment> component renders a conditional comment. Conditional comments are an IE specific feature which enables the developer to (out)comment blocks of HTML depending on whether the client is using IE and if so even which version. They are often seen in combination with CSS stylesheets like so: 

     <!--[if lte IE 7]>
     <link rel="stylesheet" href="ie6-ie7.css" />
 <![endif]-->

    However, Facelets renders the comment's contents HTML-escaped which makes it unusable. 

     <!--[if lte IE 7]&gt;
     &lt;link rel=&quot;stylesheet&quot; href=&quot;ie6-ie7.css&quot; /&gt;
 &lt;![endif]-->

    Also, if jakarta.faces.FACELETS_SKIP_COMMENTS context param is set to true then it will even not be rendered at all. You would need to workaround this with an ugly <h:outputText escape="false">. 

     <h:outputText
     value="&lt;!--[if lte IE 7]&gt;&lt;link rel=&quot;stylesheet&quot; href=&quot;ie6-ie7.css&quot; /&gt;&lt;![endif]--&gt;"
     escape="false" />

    This component is designed to solve this problem. 

     <o:conditionalComment if="lte IE 7">
     <link rel="stylesheet" href="ie6-ie7.css" />
 </o:conditionalComment>

    Note that you cannot use this with <h:outputStylesheet> as it would implicitly be relocated as direct child of <h:head>.

    Author:
    Bauke Scholtz
    See Also:
    OutputFamily