Validating empty fields with inline validation method and validator class

Question

I have the following input field:

If the field is empty it w

Answer 1

You've hit an oversight in JSF. The validator is wrapped in a MethodExpressionValidator which according to the source of its validate() method indeed skips validation when the value is null.

if (value != null) {
    try {
        ELContext elContext = context.getELContext();
        methodExpression.invoke(elContext, new Object[]{context, component, value});
        ...

This is not considering the new JSF 2.0 javax.faces.VALIDATE_EMPTY_FIELDS context parameter which defaults to true. It should actually be doing the same as UIInput#validate().

if (!isEmpty(newValue) || validateEmptyFields(context)) {
    try {
        ELContext elContext = context.getELContext();
        methodExpression.invoke(elContext, new Object[]{context, component, value});
        ...

This has already been reported as Mojarra issue 1508. I've voted it and added a new comment to wake them up.