    001// Copyright 2007-2013 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.commons.MessageFormatter;
    021import org.apache.tapestry5.services.FormSupport;
    022import org.apache.tapestry5.services.javascript.DataConstants;
    023import org.apache.tapestry5.services.javascript.JavaScriptSupport;
    024
    025/**
    026 * Validates that a string value has not exceeded a maximum length.
    027 */
    028public final class MaxLength extends AbstractValidator<Integer, String>
    029{
    030    public MaxLength(JavaScriptSupport javaScriptSupport)
    031    {
    032        super(Integer.class, String.class, "maximum-string-length", javaScriptSupport);
    033    }
    034
    035    public void validate(Field field, Integer constraintValue, MessageFormatter formatter, String value)
    036            throws ValidationException
    037    {
    038        if (value.length() > constraintValue)
    039            throw new ValidationException(buildMessage(formatter, field, constraintValue));
    040    }
    041
    042    private String buildMessage(MessageFormatter formatter, Field field, Integer constraintValue)
    043    {
    044        return formatter.format(constraintValue, field.getLabel());
    045    }
    046
    047    public void render(Field field, Integer constraintValue, MessageFormatter formatter, MarkupWriter writer,
    048                       FormSupport formSupport)
    049    {
    050        if (formSupport.isClientValidationEnabled())
    051        {
    052            javaScriptSupport.require("t5/core/validation");
    053
    054            writer.attributes(DataConstants.VALIDATION_ATTRIBUTE, true,
    055                    "data-validate-max-length", constraintValue.toString(),
    056                    "data-max-length-message", buildMessage(formatter, field, constraintValue));
    057        }
    058    }
    059}