/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you 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.myfaces.view.facelets.tag.jsf;

 import java.io.IOException;

 import javax.el.ValueExpression;

 import javax.faces.component.UIComponent;

 import javax.faces.component.ValueHolder;

 import javax.faces.context.FacesContext;

 import javax.faces.convert.Converter;

 import javax.faces.view.ValueHolderAttachedObjectHandler;

 import javax.faces.view.facelets.ComponentHandler;

 import javax.faces.view.facelets.ConverterHandler;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.MetaRuleset;

 import javax.faces.view.facelets.TagAttribute;

 import javax.faces.view.facelets.TagException;

 import javax.faces.view.facelets.TagHandlerDelegate;

 import org.apache.myfaces.view.facelets.FaceletCompositionContext;

 import org.apache.myfaces.view.facelets.tag.MetaRulesetImpl;

 /**

  * Handles setting a Converter instance on a ValueHolder. Will wire all attributes set to the Converter instance

  * created/fetched. Uses the "binding" attribute for grabbing instances to apply attributes to. <p/> Will only

  * set/create Converter is the passed UIComponent's parent is null, signifying that it wasn't restored from an existing

  * tree.

  * 

  * @author Leonardo Uribe (latest modification by $Author$)

  * @version $Revision$ $Date$

  *

  * @since 2.0

  */

 public class ConverterTagHandlerDelegate extends TagHandlerDelegate implements ValueHolderAttachedObjectHandler

 {

     private ConverterHandler _delegate;

     public ConverterTagHandlerDelegate(ConverterHandler delegate)

     {

         _delegate = delegate;

     }

     /**

      * Set Converter instance on parent ValueHolder if it's not being restored.

      * <ol>

      * <li>Cast to ValueHolder</li>

      * <li>If "binding" attribute was specified, fetch/create and re-bind to expression.</li>

      * <li>Otherwise, call {@link #createConverter(FaceletContext) createConverter}.</li>

      * <li>Call {@link ObjectHandler#setAttributes(FaceletContext, Object) setAttributes} on Converter instance.</li>

      * <li>Set the Converter on the ValueHolder</li>

      * <li>If the ValueHolder has a localValue, convert it and set the value</li>

      * </ol>

      * 

      * @see ValueHolder

      * @see Converter

      * @see #createConverter(FaceletContext)

      * @see javax.faces.view.facelets.FaceletHandler#apply(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent)

      */

     @Override

     public void apply(FaceletContext ctx, UIComponent parent) throws IOException

     {

         // only process if it's been created

         if (!ComponentHandler.isNew(parent))

         {

             return;

         }

         if (parent instanceof ValueHolder)

         {

             applyAttachedObject(ctx.getFacesContext(), parent);

         }

         else if (UIComponent.isCompositeComponent(parent))

         {

             if (getFor() == null)

             {

                 throw new TagException(_delegate.getTag(), "is nested inside a composite component"

                         + " but does not have a for attribute.");

             }

             FaceletCompositionContext mctx = FaceletCompositionContext.getCurrentInstance(ctx);

             mctx.addAttachedObjectHandler(parent, _delegate);

         }

         else

         {

             throw new TagException(_delegate.getTag(),

                     "Parent not composite component or an instance of ValueHolder: " + parent);

         }      

     }

     /**

      * Create a Converter instance

      * 

      * @param ctx

      *            FaceletContext to use

      * @return Converter instance, cannot be null

      */

     protected Converter createConverter(FaceletContext ctx)

     {

         if (_delegate.getConverterId(ctx) == null)

         {

             throw new TagException(_delegate.getTag(),

                                     "Default behavior invoked of requiring a converter-id passed in the "

                                     + "constructor, must override ConvertHandler(ConverterConfig)");

         }

         return ctx.getFacesContext().getApplication().createConverter(_delegate.getConverterId(ctx));

     }

     @Override

     public MetaRuleset createMetaRuleset(Class type)

     {

         return new MetaRulesetImpl(_delegate.getTag(), type).ignore("binding").ignore("for");

     }

     public void applyAttachedObject(FacesContext context, UIComponent parent)

     {

         // Retrieve the current FaceletContext from FacesContext object

         FaceletContext faceletContext = (FaceletContext) context.getAttributes().get(

                 FaceletContext.FACELET_CONTEXT_KEY);

         // cast to a ValueHolder

         ValueHolder vh = (ValueHolder) parent;

         ValueExpression ve = null;

         Converter c = null;

         if (_delegate.getBinding() != null)

         {

             ve = _delegate.getBinding().getValueExpression(faceletContext, Converter.class);

             c = (Converter) ve.getValue(faceletContext);

         }

         if (c == null)

         {

             c = this.createConverter(faceletContext);

             if (ve != null)

             {

                 ve.setValue(faceletContext, c);

             }

         }

         if (c == null)

         {

             throw new TagException(_delegate.getTag(), "No Converter was created");

         }

         _delegate.setAttributes(faceletContext, c);

         vh.setConverter(c);

         Object lv = vh.getLocalValue();

         FacesContext faces = faceletContext.getFacesContext();

         if (lv instanceof String)

         {

             vh.setValue(c.getAsObject(faces, parent, (String) lv));

         }

     }

     public String getFor()

     {

         TagAttribute forAttribute = _delegate.getTagAttribute("for");

         if (forAttribute == null)

         {

             return null;

         }

         else

         {

             return forAttribute.getValue();

         }

     }

 }