    001// Copyright 2006, 2007, 2008, 2012, 2014 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.ioc.internal.util.InternalUtils;
    022import org.apache.tapestry5.services.FormSupport;
    023import org.apache.tapestry5.services.Html5Support;
    024import org.apache.tapestry5.services.javascript.DataConstants;
    025import org.apache.tapestry5.services.javascript.JavaScriptSupport;
    026
    027/**
    028 * A validator that enforces that the value is not null and not the empty string. This validator is not configurable.
    029 */
    030public final class Required extends AbstractValidator<Void, Object>
    031{
    032    final private Html5Support html5Support;
    033
    034    public Required(JavaScriptSupport javaScriptSupport, Html5Support html5Support)
    035    {
    036        super(null, Object.class, "required", javaScriptSupport);
    037        this.html5Support = html5Support;
    038    }
    039
    040    public void validate(Field field, Void constraintValue, MessageFormatter formatter, Object value)
    041            throws ValidationException
    042    {
    043        if (value == null || InternalUtils.isEmptyCollection(value) || InternalUtils.isBlank(value.toString()))
    044            throw new ValidationException(buildMessage(formatter, field));
    045    }
    046
    047    private String buildMessage(MessageFormatter formatter, Field field)
    048    {
    049        return formatter.format(field.getLabel());
    050    }
    051
    052    /**
    053     * The exception to the rule.
    054     */
    055    public boolean isRequired()
    056    {
    057        return true;
    058    }
    059
    060    public void render(Field field, Void constraintValue, MessageFormatter formatter, MarkupWriter writer,
    061                       FormSupport formSupport)
    062    {
    063
    064        writer.attributes("aria-required", "true");
    065
    066        if (formSupport.isClientValidationEnabled())
    067        {
    068            javaScriptSupport.require("t5/core/validation");
    069
    070            writer.attributes(
    071                    DataConstants.VALIDATION_ATTRIBUTE, true,
    072                    "data-optionality", "required",
    073                    "data-required-message", buildMessage(formatter, field),
    074                    "aria-required", "true");
    075        }
    076        if (html5Support.isHtml5SupportEnabled())
    077        {
    078            writer.attributes("required", "required");
    079        }
    080    }
    081}