javax.faces.render.Renderer Java Examples

@Override
public void encodeBegin(FacesContext context, UIComponent component) throws IOException {
    
    String newRendererType = detectNewRendererType(context, component);
    
    // modify the control, so that this renderer won't be used in future, 
    // avoiding the overhead of delegation. Once this encode phase ends
    // the detected renderer will be used instead of this renderer. 
    component.setRendererType(newRendererType);
    
    // save the value for use in encodeChildren and encodeEnd.
    HtmlUtil.storeEncodeParameter(context, component, "newRendererType", newRendererType); //$NON-NLS-1$
    
    // the default implementation here and in the rest of the methods
    // is to delegate the rendering & decoding to the detected renderer
    Renderer delegate = findDelegate(context, component, newRendererType);
    
    delegate.encodeBegin(context, component);
}
 

private TagAttribute createElementName(Tag tag) {
	Location location = tag.getLocation();
	String ns = Namespace.p.uri;
	String myLocalName = Renderer.PASSTHROUGH_RENDERER_LOCALNAME_KEY;
	String qName = "p:" + myLocalName;
	String value = tag.getLocalName();

	return TagAttributeUtilities.createTagAttribute(location, ns, myLocalName, qName, value);
}
 

public boolean getRendersChildren() {
	if (getRendererType() != null) {
		Renderer renderer = getRenderer(getFacesContext());
		if (renderer != null) {
			return renderer.getRendersChildren();
		}
	}
	return true;
}
 

private Renderer findDelegate(FacesContext context, UIComponent component, String newRendererType) {
    String componentFamily = component.getFamily();
    Renderer delegate = FacesUtil.getRenderer(context, componentFamily, newRendererType);
    if( null == delegate ){
        // won't happen, the 2 renderer-types in the detect method both have registered renderers.
        throw new NullPointerException("Renderer is null for componentFamily="+componentFamily+" rendererType="+newRendererType); //$NON-NLS-1$ //$NON-NLS-2$
    }
    return delegate;
}
 

@Override
public void encodeChildren(FacesContext context, UIComponent component) throws IOException {
    String newRendererType = (String)HtmlUtil.readEncodeParameter(context, component, "newRendererType", /*remove*/false); //$NON-NLS-1$
    Renderer delegate = findDelegate(context, component, newRendererType);
    
    if( delegate.getRendersChildren() ){
        delegate.encodeChildren(context, component);
    }else{
        // else implement here using the default implementation.
        FacesUtil.renderChildren(context, component);
    }
}
 

@Override
public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
    String newRendererType = (String)HtmlUtil.readEncodeParameter(context, component, "newRendererType", /*remove*/false); //$NON-NLS-1$
    Renderer delegate = findDelegate(context, component, newRendererType);
    delegate.encodeEnd(context, component);
    
    HtmlUtil.removeEncodeParameter(context, component, "newRendererType"); //$NON-NLS-1$
}
 

@Override
public void decode(FacesContext context, UIComponent component) {
    // shouldn't usually happen, but default implementation provided in case of unusual use-cases,
    // like if some rendered property computation means that the control is not initially visible 
    // during the encode phase but it then evaluates differently in the decode phase so that the control is decoded.
    
    String newRendererType = detectNewRendererType(context, component);
    Renderer delegate = findDelegate(context, component, newRendererType);
    delegate.decode(context, component);
}
 

@Override
public Object getConvertedValue(FacesContext context, UIComponent component, Object submittedValue) throws ConverterException {
    // shouldn't usually happen, can be invoked in some unusual use-cases (see comment in decode).
    // This occurs in the Process Validations phase, so the encode parameter won't be available
    // so re-compute the detectRendererType
    String newRendererType = detectNewRendererType(context, component);
    Renderer delegate = findDelegate(context, component, newRendererType);
    return delegate.getConvertedValue(context, component, submittedValue);
}
 

@Override
protected Renderer getRenderer(FacesContext arg0) {
    throw new UnsupportedOperationException();
}
 

@Override
protected Renderer getRenderer(FacesContext arg0) {
    throw new UnsupportedOperationException();
}
 

@Override
protected Renderer getRenderer(FacesContext arg0) {
    throw new UnsupportedOperationException();
}
 

@Override
public Renderer getRenderer(FacesContext context) {
    return getParent().getRenderer(context);
}
 

private String detail(String componentFamily, String readOnlyRendererType,
        Renderer readOnlyRenderer) {
    String className = (null == readOnlyRenderer)? null : readOnlyRenderer.getClass().getName();
    return " family="+componentFamily+" readOnlyRendererType="+readOnlyRendererType+" readOnlyRendererClass="+className;
}