Question

I’m trying to implement a custom validation annotation in Seam.

We have a list of objects, lets call it arrayA, and arrayA is different dependent on today’s date.

Next we have an input field stringB, stringB is some value in arrayA going through a transformation function funcC(…).

So basically, we can validate stringB using the following loop:

for(a : arrayA)
{
    a.equals( funcC( stringB ) )
    return true
}
return false

My problem is, how do I do this in seam considering arrayA is dynamic? The seam/hibernate validation annotation seems to take only constants as input. Does anyone know a workaround for this problem?

Thanks!

Answer 1

You can always utilize Seam’s Component.getInstance() from within your Validator to fetch the Array from your context. This assumes that you have populated a Seam-based Bean containing this array.

For example:

@Name("someValidator")
@Validator
public class SomeValidator implements javax.faces.validator.Validator {

  public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {

    MyArrayBean bean = (MyArrayBean)Component.getInstance("myArrayBean");
    String[] arrayA = bean.getArray();

    for(String a : arrayA) {
      //etc
    }
  }
}

Alternately, if the Array can change depending on the page you are validating from; then you can always pass the value to the validator using <f:attribute>.

For example:

<h:inputText value="#{someBean.stringB}">
    <f:validator validatorId="someValidator" />
    <f:attribute name="arrayA" value="#{myArrayBean.array}"/>
</h:inputText>

And in your validator, in place of the Component.getInstance() you can load this array via the attribute:

String[] arrayA = component.getValueExpression("arrayA").getValue(context.getELContext());

[Note if passing the String[] doesn’t work then pass in the Bean containing it instead.]