/*
    * 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;
  
  import java.io.IOException;
  import java.util.Map;
  import java.util.Set;
  
  import javax.el.ELException;
  import javax.el.ValueExpression;
  import javax.faces.FacesException;
  import javax.faces.component.UIComponent;
  import javax.faces.view.facelets.Facelet;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.FaceletException;
  
  /**
   * This class is used to encapsulate the information required to resolve
   * facelets templates.
   * 
   * Composite components require to "isolate" the inner template resolution.
   * That means, when a ui:xx tag is used, do not take into account the outer
   * templates defined.
   * 
   * The methods here are only used by the current implementation and the intention
   * is not expose it as public api.
   * 
   * @author Leonardo Uribe (latest modification by $Author$)
   * @version $Revision$ $Date$
   * @since 2.0.1
   */
  public abstract class TemplateContext
  {
      /**
       * Pop the last added pushed TemplateClient
       * @see TemplateClient
       */
      public abstract TemplateManager popClient(final AbstractFaceletContext actx);
      
      /**
       * Push the passed TemplateClient onto the stack for Definition Resolution
       * @param client
       * @see TemplateClient
       */
      public abstract void pushClient(final AbstractFaceletContext actx, final AbstractFacelet owner,
                                      final TemplateClient client);
      
      /**
       * Pop the last added extended TemplateClient
       * @param actx
       */
      public abstract TemplateManager popExtendedClient(final AbstractFaceletContext actx);
      
      public abstract void extendClient(final AbstractFaceletContext actx, final AbstractFacelet owner,
                                        final TemplateClient client);
      
      /**
       * This method will walk through the TemplateClient stack to resolve and
       * apply the definition for the passed name.
       * If it's been resolved and applied, this method will return true.
       * 
       * @param parent the UIComponent to apply to
       * @param name name or null of the definition you want to apply
       * @return true if successfully applied, otherwise false
       * @throws IOException
       * @throws FaceletException
       * @throws FacesException
       * @throws ELException
       */
      public abstract boolean includeDefinition(FaceletContext ctx, Facelet owner, UIComponent parent, String name)
              throws IOException, FaceletException, FacesException, ELException;
      
      public abstract TemplateManager getCompositeComponentClient();
  
      /**
       * Set the composite component TemplateManager instance, used to resolve
       * cc:insertChildred or cc:insertFacet usages for the current template
       * context 
       */
      public abstract void setCompositeComponentClient(TemplateManager compositeComponentClient);
  
      /**
       * Return the param value expression associated to the key passed,
      * preserving the precedence of each template client. 
      * 
      * @since 2.0.8
      * @param key
      * @return
      */
     public abstract ValueExpression getParameter(String key);
     
     /**
      * Associate the param to the latest template client.
      * 
      * @since 2.0.8
      * @param key
      * @return
      */
     public abstract void setParameter(String key, ValueExpression value);
     
     /**
      * Check if no parameters are set.
      * 
      * @since 2.0.8
      * @return
      */
     public abstract boolean isParameterEmpty();
     
     /**
      * 
      * @since 2.0.8
      * @return
      */
     public abstract Map<String, ValueExpression> getParameterMap();
 
     /**
      * 
      * @since 2.0.8
      * @return
      */
     public abstract boolean isAllowCacheELExpressions();
 
     /**
      * 
      * @since 2.0.8
      * @return
      */
     public abstract void setAllowCacheELExpressions(boolean cacheELExpressions);
     
     /**
      * 
      * @since 2.1.12
      * @param key
      * @return 
      */
     public abstract boolean containsParameter(String key);
     
     /**
      * Return a set of the parameters known associated to this template context and/or
      * template. This logic is used to detect which EL Expressions can be cached or not.
      * 
      * @since 2.1.12
      * @return 
      */
     public abstract Set<String> getKnownParameters();
     
     /**
      * 
      * @since 2.1.12
      * @param key
      * @return 
      */
     public abstract boolean containsKnownParameter(String key);
     
     /**
      * 
      * @since 2.1.12
      * @return 
      */
     public abstract boolean isKnownParametersEmpty();
     
     /**
      * 
      * @since 2.1.12
      * @param knownParameters 
      */
     public abstract void addKnownParameters(String knownParameters);
 }