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