// Copyright 2006, 2008, 2009 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.bindings;

 import org.apache.tapestry5.Binding;

 import org.apache.tapestry5.ComponentResources;

 import org.apache.tapestry5.Field;

 import org.apache.tapestry5.FieldValidator;

 import org.apache.tapestry5.internal.services.StringInterner;

 import org.apache.tapestry5.ioc.Location;

 import org.apache.tapestry5.ioc.internal.util.TapestryException;

 import org.apache.tapestry5.services.BindingFactory;

 import org.apache.tapestry5.services.FieldValidatorSource;

 /**

  * Factory for bindings that provide a {@link org.apache.tapestry5.FieldValidator} based on a validator specification.

  * This binding factory is only useable with components that implement the {@link org.apache.tapestry5.Field}

  * interface.

  */

 public class ValidateBindingFactory implements BindingFactory

 {

     private final FieldValidatorSource fieldValidatorSource;

     private final StringInterner interner;

     public ValidateBindingFactory(FieldValidatorSource fieldValidatorSource, StringInterner interner)

     {

         this.fieldValidatorSource = fieldValidatorSource;

         this.interner = interner;

     }

     public Binding newBinding(String description, ComponentResources container,

                               ComponentResources component, final String expression, Location location)

     {

         Object fieldAsObject = component.getComponent();

         if (!Field.class.isInstance(fieldAsObject))

             throw new TapestryException(BindingsMessages.validateBindingForFieldsOnly(component),

                                         location, null);

         final Field field = (Field) fieldAsObject;

         return new InvariantBinding(location, FieldValidator.class, interner.intern(description + ": " + expression))

         {

             public Object get()

             {

                 // The expression is a validator specification, such as "required,minLength=5".

                 // ValidatorBindingFactory is the odd man out becasuse it needs the binding component (the

                 // component whose parameter is to be bound) rather than the containing component, the way

                 // most factories work.

                 return fieldValidatorSource.createValidators(field, expression);

             }

         };

     }

 }