/*

  * 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 java.util.ArrayList;

 import java.util.List;

 import javax.el.ValueExpression;

 import javax.faces.FacesWrapper;

 import javax.faces.component.EditableValueHolder;

 import javax.faces.component.UIComponent;

 import javax.faces.context.FacesContext;

 import javax.faces.validator.Validator;

 import javax.faces.view.EditableValueHolderAttachedObjectHandler;

 import javax.faces.view.facelets.ComponentHandler;

 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 javax.faces.view.facelets.ValidatorHandler;

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

 import org.apache.myfaces.shared.renderkit.JSFAttr;

 import org.apache.myfaces.shared.util.WebConfigParamUtils;

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

 import org.apache.myfaces.view.facelets.compiler.FaceletsCompilerUtils;

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

 /**

  * Handles setting a Validator instance on a EditableValueHolder. Will wire all attributes set to the Validator instance

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

  * set/create Validator 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 ValidatorTagHandlerDelegate extends TagHandlerDelegate 

     implements EditableValueHolderAttachedObjectHandler, FacesWrapper<ValidatorHandler>

 {

     /**

      * if <f:validateBean> has no children and its disabled attribute is true,

      * its validatorId will be added to the exclusion list stored under

      * this key on the parent UIComponent.

      */

     public final static String VALIDATOR_ID_EXCLUSION_LIST_KEY

             = "org.apache.myfaces.validator.VALIDATOR_ID_EXCLUSION_LIST";

     /**

      * Enforce f:validateBean to be called first before any JSF validator.

      */

     @JSFWebConfigParam(defaultValue="false", expectedValues="true, false", since = "2.2.10", group="validation")

     private final static String BEAN_BEFORE_JSF_VALIDATION

             = "org.apache.myfaces.validator.BEAN_BEFORE_JSF_VALIDATION";

     private final static String BEAN_BEFORE_JSF_PROPERTY = "oam.beanBeforeJsf";

     private ValidatorHandler _delegate;

     /**

      * true - this tag has children

      * false - this tag is a leave

      */

     private final boolean _wrapMode;

     private Boolean _beanBeforeJsfValidation;

     public ValidatorTagHandlerDelegate(ValidatorHandler delegate)

     {

         _delegate = delegate;

         // According to jsf 2.0 spec section 10.4.1.4

         // this tag can be used as a leave within an EditableValueHolder

         // or as a container to provide validator information for all 

         // EditableValueHolder-children (and grandchildren and ...)

         // (this behavior is analog to <f:ajax>)

         // --> Determine if we have children:

         _wrapMode = FaceletsCompilerUtils.hasChildren(_delegate.getValidatorConfig());

         _beanBeforeJsfValidation = null;

     }

     @Override

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

     {

         // we need methods from AbstractFaceletContext

         FaceletCompositionContext mctx = FaceletCompositionContext.getCurrentInstance(ctx);

         if (_wrapMode)

         {

             // the tag has children --> provide validator information for all children

             // FIXME the spec says we should save the validation groups in an attribute

             // on the parent UIComponent, but this will be a problem in the following scenario:

             // <h:form>

             //     <f:validateBean>

             //         <h:inputText />

             //     </f:validateBean>

             //     <h:inputText />

             // </h:form>

             // because the validator would also be applied to the second h:inputText,

             // which it should not, on my opinion. In addition, mojarra also does not

             // attach the validator to the second h:inputText in this scenario (blackbox test).

             // So I use the same way as f:ajax for this problem. -=Jakob Korherr=-

             String validatorId = _delegate.getValidatorConfig().getValidatorId();

             /*

             boolean disabled = _delegate.isDisabled(ctx);

             if (disabled)

             {

                 // the validator is disabled --> add its id to the exclusion stack

                 boolean validatorIdAvailable = validatorId != null && !"".equals(validatorId);

                 try

                 {

                     if (validatorIdAvailable)

                     {

                         mctx.pushExcludedValidatorIdToStack(validatorId);

                     }

                     _delegate.getValidatorConfig().getNextHandler().apply(ctx, parent);

                 }

                 finally

                 {

                     if (validatorIdAvailable)

                     {

                         mctx.popExcludedValidatorIdToStack();

                     }

                 }

             }

             else

             {*/

                 // the validator is enabled 

                 // --> add the validation groups and the validatorId to the stack

                 //String groups = getValidationGroups(ctx);

                 // spec: don't save the validation groups string if it is null or empty string

                 //boolean groupsAvailable = groups != null 

                         //&& !groups.matches(BeanValidator.EMPTY_VALIDATION_GROUPS_PATTERN);

                 //try

                 //{

                     //if (groupsAvailable)

                     //{

                     //    mctx.pushValidationGroupsToStack(groups);

                     //}

                     try

                     {

                         mctx.pushEnclosingValidatorIdToStack(validatorId, this);

                         _delegate.applyNextHandler(ctx, parent);

                     }

                     finally

                     {

                         mctx.popEnclosingValidatorIdToStack();

                     }

                 //}

                 //finally

                 //{

                     //if (groupsAvailable)

                     //{

                         //mctx.popValidationGroupsToStack();

                     //}

                 //}

             /*}*/

         }

         else

         {

             // Apply only if we are creating a new component

             if (!ComponentHandler.isNew(parent))

             {

                 return;

             }

             // the tag is a leave --> attach validator to parent

             if (parent instanceof EditableValueHolder)

             {

                 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.");

                 }

                 mctx.addAttachedObjectHandler(parent, _delegate);

             }

             else

             {

                 throw new TagException(_delegate.getTag(),

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

             }

         }

     }

     /**

      * Template method for creating a Validator instance

      * 

      * @param ctx FaceletContext to use

      * @return a new Validator instance

      */

     protected Validator createValidator(FaceletContext ctx)

     {

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

         {

             throw new TagException(_delegate.getTag(), "Default behavior invoked of requiring " +

                     "a validator-id passed in the constructor, must override ValidateHandler(ValidatorConfig)");

         }

         return ctx.getFacesContext().getApplication().createValidator(_delegate.getValidatorId(ctx));

     }

     @Override

     public MetaRuleset createMetaRuleset(Class type)

     {

         MetaRuleset metaRuleset = new MetaRulesetImpl(_delegate.getTag(), type);

         // ignore binding and disabled, because they are handled by DelegatingMetaTagHandler

         metaRuleset.ignore(JSFAttr.BINDING_ATTR).ignore(JSFAttr.DISABLED_ATTR);

         // ignore for, because it is handled by FaceletsAttachedObjectHandler

         metaRuleset.ignore(JSFAttr.FOR_ATTR);

         return metaRuleset;

     }

     @SuppressWarnings("unchecked")

     public void applyAttachedObject(FacesContext context, UIComponent parent)

     {

         // Retrieve the current FaceletContext from FacesContext object

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

                 FaceletContext.FACELET_CONTEXT_KEY);

         // spec: if the disabled attribute is true, the validator should not be added.

         // in addition, the validatorId, if present, should be added to an exclusion

         // list on the parent component to prevent a default validator with the same

         // id from beeing registered on the component.

         if (_delegate.isDisabled(faceletContext))

         {

             // tag is disabled --> add its validatorId to the parent's exclusion list

             String validatorId = _delegate.getValidatorConfig().getValidatorId();

             if (validatorId != null && !"".equals(validatorId))

             {

                 List<String> exclusionList = (List<String>) parent.getAttributes()

                         .get(VALIDATOR_ID_EXCLUSION_LIST_KEY);

                 if (exclusionList == null)

                 {

                     exclusionList = new ArrayList<String>();

                     parent.getAttributes().put(VALIDATOR_ID_EXCLUSION_LIST_KEY, exclusionList);

                 }

                 exclusionList.add(validatorId);

             }

         }

         else

         {

             // tag is enabled --> create the validator and attach it

             // cast to a ValueHolder

             EditableValueHolder evh = (EditableValueHolder) parent;

             ValueExpression ve = null;

             Validator v = null;

             if (_delegate.getBinding() != null)

             {

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

                 v = (Validator) ve.getValue(faceletContext);

             }

             if (v == null)

             {

                 v = this.createValidator(faceletContext);

                 if (ve != null)

                 {

                     ve.setValue(faceletContext, v);

                 }

             }

             if (v == null)

             {

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

             }

             _delegate.setAttributes(faceletContext, v);

             if (shouldBeanBeforeJsfValidationEnabled(context))

             {

                 parent.getAttributes().put(BEAN_BEFORE_JSF_PROPERTY, Boolean.TRUE);

             }

             evh.addValidator(v); 

         }

     }

     private boolean shouldBeanBeforeJsfValidationEnabled(FacesContext context)

     {

         if (_beanBeforeJsfValidation == null)

         {

             _beanBeforeJsfValidation = WebConfigParamUtils.getBooleanInitParameter(context.getExternalContext(),

                     BEAN_BEFORE_JSF_VALIDATION, false);

         }

         return _beanBeforeJsfValidation;

     }

     public String getFor()

     {

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

         if (forAttribute == null)

         {

             return null;

         }

         else

         {

             return forAttribute.getValue();

         }

     }

     public String getValidationGroups(FaceletContext ctx)

     {

         TagAttribute attribute = _delegate.getTagAttribute("validationGroups");

         if (attribute == null)

         {

             return null;

         }

         else

         {

             return attribute.getValue(ctx);

         }

     }

     public ValidatorHandler getWrapped()

     {

         return _delegate;

     }

 }