Support for <p:pickList> in ValidateMultipleFields

[matinh]

OmniFaces provides validators that validate multiple fields at a time, like <o:validateAll>, <o:validateMultiple>, etc. These validators won't work with PrimeFaces' pickList components, due to the lack of support for the DualListModel used by this component.

The problem for validateAll is in the method isEmpty() from the Utils class. Other component do validation different.

Adding another instanceof statement in this method would solve the problem for the validateAll component, but introduce a dependency to PrimeFaces, which is probably unwanted. Maybe there is a more elegant solution for this?

[BalusC]

As you say, introducing a PrimeFaces dependency in OmniFaces isn't a good idea :)

You could work around the <o:validateAll> issue with a custom DualListModel which implements Collection and delegates to DualListModel#getTarget().

E.g.

public class CustomDualListModel<T> extends DualListModel<T> implements Collection {

	public CustomDualListModel(List<T> source, List<T> target) {
		super(source, target);
	}

	@Override
	public boolean isEmpty() {
		return getTarget().isEmpty();
	}

	@Override
	public int size() {
		return getTarget().size();
	}

	@Override
	public boolean contains(Object o) {
		return getTarget().contains(o);
	}

	// Etc ...
}

The Utils#isEmpty() supports Collection.

[matinh]

Thank's for the hint with implementing Collection. However, this doesn't work out of the box, as PrimeFaces' PickListRenderer has a getConvertedValue() method which looks something like this:

        // ...
        String[][] value = (String[][]) submittedValue;
        String[] sourceValue = value[0];
        String[] targetValue = value[1];
        DualListModel model = new DualListModel();   // <--- problematic

        pickList.populateModel(context, sourceValue, model.getSource());
        pickList.populateModel(context, targetValue, model.getTarget());

        return model;

Thus, for your suggestion to work, one would have to implement a custom renderer that overrides getConvertedValue() and uses the CustomDualListModel from above instead of DualListModel.
For the renderer to be used by JSF you have to add the following lines to your faces-config.xml:

<render-kit>
  <renderer>
    <component-family>org.primefaces.component</component-family>
    <renderer-type>org.primefaces.component.PickListRenderer</renderer-type>
    <renderer-class>my.company.MyPickListRenderer</renderer-class>
  </renderer>
</render-kit>

See this StackOverflow answer for details on how to use your own renderer.

However, once the custom renderer is used, the CustomDualListModel workaround works just fine. Thanks!

[matinh]

For the records: there seems to be some other bug (maybe a PrimeFaces bug?) that might get triggered by <o:validateAll>. Details can be found on StackOverflow or PrimeFaces issue #4756.

[matinh]

It turned out, that the PrimeFaces issue #4756 seems to be a Mojarra bug: #4398.