How to create a composite component for a datatable column?

Question

Given this datatable (naturally working):

  
   HEA         


        

Answer 1

The element must be an instance of UIColumn as that's the only valid child of a UIData component during the render response phase. All other UIComponent types will be ignored, thus not rendered. A composite component is implicitly a UINamingContaner component, which isn't a UIColumn and therefore ignored.

A PrimeFaces with a backing component that extends UIColumn also won't work due to the wrong lifecycle of a composite component. The column has to be created during the view build time, while the composite component's body is created during view render time.

The solution is to create a tag file instead, which means an extra .taglib.xml file, yet it works flawlessly.

/WEB-INF/tags/column.xhtml:

    
        HEADER
        
    

/WEB-INF/my.taglib.xml:

    http://example.com/my
    
        column
        tags/column.xhtml
        
            Column value
            val
        
    

Note: The entries are not mandatory, but are nice for documentation purposes, such as generated docs and IDE autocomplete.

/WEB-INF/web.xml:

    javax.faces.FACELETS_LIBRARIES
    /WEB-INF/my.taglib.xml

Usage: