    001// Copyright 2007, 2008 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5.internal.services;
    016
    017import org.apache.tapestry5.*;
    018import org.apache.tapestry5.commons.MessageFormatter;
    019import org.apache.tapestry5.services.FormSupport;
    020
    021public class FieldValidatorImpl implements FieldValidator
    022{
    023    private final Field field;
    024
    025    private final Object constraintValue;
    026
    027    private final MessageFormatter messageFormatter;
    028
    029    private final Validator validator;
    030
    031    private final FormSupport formSupport;
    032
    033    public FieldValidatorImpl(Field field, Object constraintValue, MessageFormatter messageFormatter,
    034                              Validator validator, FormSupport formSupport)
    035    {
    036        this.field = field;
    037        this.constraintValue = constraintValue;
    038        this.messageFormatter = messageFormatter;
    039        this.validator = validator;
    040        this.formSupport = formSupport;
    041    }
    042
    043    @SuppressWarnings("unchecked")
    044    public void validate(Object value) throws ValidationException
    045    {
    046        if (!validator.isRequired() && isBlank(value)) return;
    047
    048        if (value != null && !validator.getValueType().isInstance(value)) return;
    049
    050        validator.validate(field, constraintValue, messageFormatter, value);
    051    }
    052
    053    @SuppressWarnings("unchecked")
    054    public void render(MarkupWriter writer)
    055    {
    056        validator.render(field, constraintValue, messageFormatter, writer, formSupport);
    057    }
    058
    059    public boolean isRequired()
    060    {
    061        return validator.isRequired();
    062    }
    063
    064    private boolean isBlank(Object value)
    065    {
    066        return value == null || value.equals("");
    067    }
    068
    069}