The Facelets framework supports the definition of smaller, reusable view elements that can be combined at runtime using the Facelets UI tag library. Some of these tags, such as the
<ui:component> tags, trim their surrounding content. This behavior is desirable when including content from one complete XHTML document within another complete XHTML document.
There are cases, however, when we do not want Facelets to trim the content outside the Facelets tag, such as when we are decorating content on one page with additional JSF or HTML markup defined in another page.
For example, suppose there is a section of content in our XHTML document that we want to wrap or "decorate" with an HTML
<div> element defined ...