/*
    * 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.view.facelets.AbstractFaceletContext;
  import org.apache.myfaces.view.facelets.ELExpressionCacheMode;
  
  /**
   * Simplified implementation of c:set
   * 
   * Sets the result of an expression evaluation in a 'scope'
   * 
   * @author Jacob Hookom
   * @version $Id: SetHandler.java 1189343 2011-10-26 17:53:36Z struberg $
   */
  @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);
                 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));
         }
     }
 }