patroncodevalidator.java

Tapestry的一个练习例子

package com.ttdev.helloworld;

import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.form.FormComponentContributorContext;
import org.apache.tapestry.form.IFormComponent;
import org.apache.tapestry.form.ValidationMessages;
import org.apache.tapestry.form.validator.Validator;
import org.apache.tapestry.valid.ValidatorException;

public class PatronCodeValidator implements Validator {
	private KnownPatrons knownPatrons;

	public void setKnownPatrons(KnownPatrons knownPatrons) {
		this.knownPatrons = knownPatrons;
	}

	public void validate(IFormComponent field, ValidationMessages messages,
			Object object) throws ValidatorException {
		String patronId = (String) object;
		if (!knownPatrons.isKnown(patronId)) {
			throw new ValidatorException("Patron not found", null);
		}
	}

	public boolean getAcceptsNull() {
		return false;
	}

	public void renderContribution(IMarkupWriter writer, IRequestCycle cycle,
			FormComponentContributorContext context, IFormComponent field) {
	}

	public boolean isRequired() {
		return false;
	}
}