// Copyright 2007 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.internal.beaneditor;

 import org.apache.tapestry5.beaneditor.Validate;

 import org.apache.tapestry5.ioc.AnnotationProvider;

 import org.apache.tapestry5.services.ValidationConstraintGenerator;

 import java.util.Arrays;

 import java.util.List;

 /**

  * Checks for the {@link Validate} annotation, and extracts its value to form the result.

  */

 public class ValidateAnnotationConstraintGenerator implements ValidationConstraintGenerator

 {

     public List<String> buildConstraints(Class propertyType, AnnotationProvider annotationProvider)

     {

         Validate annotation = annotationProvider.getAnnotation(Validate.class);

         if (annotation == null)

             return null;

         //TAP5-520: Commas within regular expressions like {n,m} or {n,} or a\,b .

         //We use Negative Lookahead to avoid matching the case a\,b .

         //We use Positive Lookahead to avoid matching cases {n,m} and {n,}.

         //http://www.regular-expressions.info/lookaround.html

         return Arrays.asList(annotation.value().split("(?<!\\\\),(?!([0-9]*\\}))"));

     }

 }