/*

  * 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.jstl.core;

 import java.io.IOException;

 import javax.el.ELContext;

 import javax.el.ELException;

 import javax.el.ValueExpression;

 import javax.faces.FacesException;

 import javax.faces.component.UIComponent;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.FaceletException;

 import javax.faces.view.facelets.TagAttribute;

 import javax.faces.view.facelets.TagConfig;

 import javax.faces.view.facelets.TagException;

 import javax.faces.view.facelets.TagHandler;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletAttribute;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletTag;

 import org.apache.myfaces.util.ExternalSpecifications;

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

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

 import org.apache.myfaces.view.facelets.el.CacheableValueExpressionUELWrapper;

 import org.apache.myfaces.view.facelets.el.CacheableValueExpressionWrapper;

 /**

  * Simplified implementation of c:set

  * 

  * Sets the result of an expression evaluation in a 'scope'

  * 

  * @author Jacob Hookom

  * @version $Id$

  */

 @JSFFaceletTag(name="c:set")

 public class SetHandler extends TagHandler

 {

     /**

      * Name of the exported scoped variable to hold the value

      * specified in the action. The type of the scoped variable is

      * whatever type the value expression evaluates to.

      */

     @JSFFaceletAttribute(className="java.lang.String")

     private final TagAttribute var;

     /**

      * Expression to be evaluated.

      */

     @JSFFaceletAttribute(

             className="javax.el.ValueExpression",

             deferredValueType="java.lang.Object")

     private final TagAttribute value;

     @JSFFaceletAttribute(

             name="scope",

             className="java.lang.String",

             longDescription="Scope for var.")

     private final TagAttribute scope;

     @JSFFaceletAttribute(

         name="target",

         className="java.lang.String",

         longDescription="Target object whose property will be set."+

         " Must evaluate to a JavaBeans object with setter property"+

         "property, or to a java.util.Map object.")

     private final TagAttribute target;

     @JSFFaceletAttribute(

         name="property",

         className="java.lang.String",

         longDescription="Name of the property to be set in the target object.")

     private final TagAttribute property;

     public SetHandler(TagConfig config)

     {

         super(config);

         this.value = this.getAttribute("value");

         this.var = this.getAttribute("var");

         this.scope = this.getAttribute("scope");

         this.target = this.getAttribute("target");

         this.property = this.getAttribute("property");

     }

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

             ELException

     {

         ValueExpression veObj = this.value.getValueExpression(ctx, Object.class);

         if (this.var != null)

         {

             // Get variable name

             String varStr = this.var.getValue(ctx);

             if (this.scope != null)

             {

                 String scopeStr = this.scope.getValue(ctx);

                 // Check scope string

                 if (scopeStr == null || scopeStr.length() == 0)

                 {

                     throw new TagException(tag, "scope must not be empty");

                 }

                 if ("page".equals(scopeStr))

                 {

                     throw new TagException(tag, "page scope is not allowed");

                 }

                 // Build value expression string to set variable

                 StringBuilder expStr = new StringBuilder().append("#{").append(scopeStr);

                 if ("request".equals(scopeStr) || "view".equals(scopeStr) || "session".equals(scopeStr)

                         || "application".equals(scopeStr))

                 {

                     expStr.append("Scope");

                 }

                 expStr.append(".").append(varStr).append("}");

                 ELContext elCtx = ctx.getFacesContext().getELContext();

                 ValueExpression expr = ctx.getExpressionFactory().createValueExpression(

                         elCtx, expStr.toString(), Object.class);

                 expr.setValue(elCtx, veObj.getValue(elCtx));

             }

             else

             {

                 //ctx.getVariableMapper().setVariable(varStr, veObj);

                 AbstractFaceletContext actx = ((AbstractFaceletContext) ctx);

                 if (ELExpressionCacheMode.alwaysRecompile.equals(actx.getELExpressionCacheMode()))

                 {

                     if (ExternalSpecifications.isUnifiedELAvailable())

                     {

                         actx.getPageContext().getAttributes().put(varStr, 

                             new CacheableValueExpressionUELWrapper(veObj));

                     }

                     else

                     {

                         actx.getPageContext().getAttributes().put(varStr, 

                             new CacheableValueExpressionWrapper(veObj));

                     }

                 }

                 else

                 {

                     actx.getPageContext().getAttributes().put(varStr, veObj);

                 }

                 if (actx.getPageContext().isAllowCacheELExpressions())

                 {

                     if (ELExpressionCacheMode.strict.equals(actx.getELExpressionCacheMode()))

                     {

                         actx.getPageContext().setAllowCacheELExpressions(false);

                     }

                 }

             }

         }

         else

         {

             // Check attributes

             if (this.target == null || this.property == null || this.value == null)

             {

                 throw new TagException(

                         tag, "either attributes var and value or target, property and value must be set");

             }

             if (this.target.isLiteral())

             {

                 throw new TagException(tag, "attribute target must contain a value expression");

             }

             // Get target object and name of property to set

             ELContext elCtx = ctx.getFacesContext().getELContext();

             ValueExpression targetExpr = this.target.getValueExpression(ctx, Object.class);

             Object targetObj = targetExpr.getValue(elCtx);

             String propertyName = this.property.getValue(ctx);

             // Set property on target object

             ctx.getELResolver().setValue(elCtx, targetObj, propertyName, veObj.getValue(elCtx));

         }

     }

 }