Question

The JSF component SelectOneRadio layout is very limited so I wrote a custom Renderer for it, and it works great. However, there are times when I want to use the standard SelectOneRadio layout as well. So I decide to make my new component that utilize the custom Renderer I create, but I want this new component to mirror the functionality of SelectOneRadio, and the only different is that it will use my Renderer. Do I need to create both custom tag and custom component to go with my custom renderer in this case? What class should I extends to obtain all functionalities from SelectOneRadio? I would greatly appreciated if you can provided some codes.

EDIT
@BalusC: I like your idea about detecting the value of layout to delegate the correct renderer. So if I have layout=”div_layout”, then it works great, but if it is pageDirection or lineDirection and nothing show up. What I did is: I create a class that extends MenuRenderer and I override encodeEnd method, so in there I did this

String layout = (String) component.getAttributes().get("layout");

if(layout != null){
        if(layout.equals(PAGE_DIRECTION) || layout.equals(LINE_DIRECTION)){
            super.encodeEnd(context, component);
            return;
        } else if (!layout.equals(DIV_LAYOUT)){
            //Throw error message
        }
}
//Continue with my own renderer code

EDIT2
Above when I said nothing show up, I was wrong. super.encodeEnd(context, component); did render, but instead of render the radio, it render select option tag. So it seems that I delegate to the wrong renderer. I need to use RadioRenderer instead of MenuRenderer.

Answer 1

If it’s specific to your own web application, then you could replace just alone the renderer. Easiest is to extend the implementation specific renderer and then depending on the value of one of the standard attributes (layout is the best choice) either delegate to the implementation specific renderer, or do your own custom rendering job.

I case of Mojarra, you’d like to extend com.sun.faces.renderkit.html_basic.RadioRenderer and then register it as follows

<renderkit>
    <renderer>
        <component-family>javax.faces.SelectOne</component-family>
        <renderer-type>javax.faces.Radio</renderer-type>
        <renderer-class>com.example.ExtendedRadioRenderer</renderer-class>
    </renderer>
</renderkit>

If you wish to be implementation independent, then you’d need to write the entire renderer implementation yourself.

If you wish to have a custom component for it, then you’d need to write it yourself as well.