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.validator;
016
017import org.apache.tapestry5.Field;
018import org.apache.tapestry5.MarkupWriter;
019import org.apache.tapestry5.ValidationException;
020import org.apache.tapestry5.ioc.MessageFormatter;
021import org.apache.tapestry5.services.FormSupport;
022
023/**
024 * Validates that a string value has a minimum length.
025 */
026public final class MinLength extends AbstractValidator<Integer, String>
027{
028    public MinLength()
029    {
030        super(Integer.class, String.class, "minimum-string-length");
031    }
032
033    public void validate(Field field, Integer constraintValue, MessageFormatter formatter, String value)
034            throws ValidationException
035    {
036        if (value.length() < constraintValue)
037            throw new ValidationException(buildMessage(formatter, field, constraintValue));
038    }
039
040    private String buildMessage(MessageFormatter formatter, Field field, Integer constraintValue)
041    {
042        return formatter.format(constraintValue, field.getLabel());
043    }
044
045    public void render(Field field, Integer constraintValue, MessageFormatter formatter, MarkupWriter writer,
046                       FormSupport formSupport)
047    {
048        formSupport.addValidation(field, "minlength", buildMessage(formatter, field, constraintValue), constraintValue);
049    }
050}