/*
    * $Id: AttributeContext.java 736275 2009-01-21 09:58:20Z apetrelli $
    *
    * 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.tiles;
  
  import java.util.Map;
  import java.util.Iterator;
  import java.util.Set;
  
  /***
   * Encapsulation of the current state of execution.
   *
   * @since Tiles 2.0
   * @version $Rev: 736275 $ $Date: 2009-01-21 10:58:20 +0100 (mer, 21 gen 2009) $
   */
  public interface AttributeContext {
  
      /***
       * Returns the attribute that will be used to render a template.
       *
       * @return The template attribute.
       * @since 2.1.2
       */
      Attribute getTemplateAttribute();
  
      /***
       * Sets the template attribute, that will be used to render the template
       * page.
       *
       * @param templateAttribute The template attribute.
       * @since 2.1.2
       */
      void setTemplateAttribute(Attribute templateAttribute);
  
      /***
       * Get associated preparer instance.
       *
       * @return The preparer name.
       * @since 2.1.0
       */
      String getPreparer();
  
      /***
       * Set associated preparer instance.
       *
       * @param url The preparer name.
       * @since 2.1.0
       */
      void setPreparer(String url);
  
      /***
       * Add all attributes to the context.
       *
       * @param newAttributes the attributes to be added.
       */
      void addAll(Map<String, Attribute> newAttributes);
  
      /***
       * Add all attributes to the context.
       *
       * @param defaultAttributes attributes which should be present.
       */
      void addMissing(Map<String, Attribute> defaultAttributes);
  
      /***
       * Copies the cascaded attributes to this attribute context.
       *
       * @param parent The parent context to be used.
       * @since 2.1.0
       */
      void inheritCascadedAttributes(AttributeContext parent);
  
      /***
       * Copies all missing attributes from the <code>parent</code> attribute
       * context to this one.
       *
       * @param parent The attribute context to copy attributes from.
       * @since 2.1.0
       */
      void inherit(AttributeContext parent);
  
      /***
      * Retrieve the named attribute, either cascaded or not.
      *
      * @param name key name for the attribute.
      * @return Attribute associated with the given name.
      */
     Attribute getAttribute(String name);
 
     /***
      * Retrieve the attribute that has been defined in this context (i.e. not
      * cascaded).
      *
      * @param name key name for the attribute.
      * @return Attribute The local attribute associated with the given name, if
      * present, or <code>null</code> otherwise.
      * @since 2.1.0
      */
     Attribute getLocalAttribute(String name);
 
     /***
      * Retrieve the attribute that has been cascaded at upper levels.
      *
      * @param name key name for the attribute.
      * @return Attribute The cascaded attribute associated with the given name,
      * if present, or <code>null</code> otherwise.
      * @since 2.1.0
      */
     Attribute getCascadedAttribute(String name);
 
     /***
      * Iterator of all attribute names.
      *
      * @return iterator of all names.
      * @deprecated Use {@link AttributeContext#getLocalAttributeNames()} or
      * {@link AttributeContext#getCascadedAttributeNames()}.
      */
     @Deprecated
     Iterator<String> getAttributeNames();
 
     /***
      * Returns the names of the local attributes, i.e. the one that have not
      * been cascaded.
      *
      * @return The local attribute names.
      * @since 2.1.0
      */
     Set<String> getLocalAttributeNames();
 
     /***
      * Returns the names of the cascaded attributes.
      *
      * @return The cascaded attribute names.
      * @since 2.1.0
      */
     Set<String> getCascadedAttributeNames();
 
     /***
      * Add the specified attribute. The attribute value will be available only
      * in the current context, i.e. it is like calling
      * {@link AttributeContext#putAttribute(String, Attribute, boolean)} with
      * <code>cascade = false</code>.
      *
      * @param name name of the attribute
      * @param value value of the attribute
      */
     void putAttribute(String name, Attribute value);
 
     /***
      * Add the specified attribute.
      *
      * @param name name of the attribute
      * @param value value of the attribute
      * @param cascade If <code>true</code>, the attribute value will be
      * available in all nested contexts. If <code>false</code>, it will be
      * available only in the current context.
      * @since 2.1.0
      */
     void putAttribute(String name, Attribute value, boolean cascade);
 
     /***
      * Clear the attributes.
      */
     void clear();
 }