Custom JSF component with custom value datatype

Question

I've created a simple custom JSF component with a decode, encodeBegin as follows:
public void decode(FacesContext context) {
    Map<String, String> requestParameters = context.getExternalContext().getRequestParameterMap();
    String clientId = getClientId(context);
    String value = requestParameters.get(clientId);
    setSubmittedValue(value);
    super.decode(context);
public void encodeBegin(FacesContext context) throws IOException {
    ResponseWriter response = context.getResponseWriter();
    String clientId = getClientId(context);
    response.startElement("input", this);
    response.writeAttribute("name", clientId, "id");
    response.writeAttribute("type", "text", null);
    String value = (String) getValue();
    if (null != value) {
         response.writeAttribute("value", value, "value");
    response.endElement("input");
}With also:
setRendererType(null);as part of the constructor.
This component works just fine both inside and outside of a dataTable component, as expected.
What I would like to do now is to replace the String value datatype with a custom class, for example MyDataType. For this I do:
public void decode(FacesContext context) {
    Map<String, String> requestParameters = context.getExternalContext().getRequestParameterMap();
    String clientId = getClientId(context);
    String value = requestParameters.get(clientId);
    MyDataType myData = (MyDataType) getValue();
    MyDataType newData = (MyDataType) myData.clone();
    newData.setValue(value);
    // copy old object and only update the changed field of this object
    setSubmittedValue(newData);
    super.decode(context);
public void encodeBegin(FacesContext context) throws IOException {
    ResponseWriter response = context.getResponseWriter();
    String clientId = getClientId(context);
    response.startElement("input", this);
    response.writeAttribute("name", clientId, "id");
    response.writeAttribute("type", "text", null);
    MyDataType value = (MyDataType) getValue();
    if (null != value) {
         response.writeAttribute("value", value.getValue(), "value");
    response.endElement("input");
}Now this works perfect outside of a dataTable component, but inside it fails to update the property on the BB.
Are there somewhere examples on how to properly use custom datatypes as values for UIInput components? Also how to only partially update the value (like I do, I only want to update the value field of the MyDataType object)

Answer 1

Even if I encode the entire MyDataType via hidden input elements and decode it again (i.e. not using a cloned getValue) it's still not working side a dataTable.
Could it have to do something with me using Facelets?