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Public API for the Apache MyFaces Trinidad project
There is a newer version: 2.2.1
/*
 * 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.trinidad.context;


import java.util.Map;

import javax.faces.context.FacesContext;

/**
 * Abstract implementation for code that provides page flow scopes;  this
 * may be overridden.
 * 
 *  To override this, provide a file on the classpath at
 *  /META-INF/services/org.apache.myfaces.trinidad.context.PageFlowScopeProvider
 *  with the name of the alternative implementation.  (There's no current
 *  support for decoration, and this general approach may be revisited
 *  in the future.)
 *  
 */
public abstract class PageFlowScopeProvider
{  
  /**
   */
  protected PageFlowScopeProvider()
  {
  }

  /**
   * Returns the current PageFlowScope, including any calls
   * to pushPageFlowScope() or popPageFlowScope().
   * 
   * @param context the current FacesContext
   */
  public abstract Map getPageFlowScope(FacesContext context); 

  /**
   * Pushes a new process scope onto the stack.
   *
   * @param context the current FacesContext
   * @param copyParent if true, all values from the parent process
   *   scope will be copied into the new process scope.
   * @return the new scope
   */
  public abstract Map pushPageFlowScope(
    FacesContext context,
    boolean copyParent);

  /**
   * Pushes a new process scope onto the stack.
   *
   * @param context the current FacesContext
   * @param discardScope if true, the scope will be immediately destroyed.
   *   if false, the scope may be available (for back button use, for 
   *   example), but this is at the discretion of the implementation,
   *   which may aggressively destroy page flow scopes in some circumstances.
   */
  public abstract Map popPageFlowScope(FacesContext context, boolean discardScope);

  /**
   * Encode the page flow scope into the current URL for processing
   * in later requests.
   *
   * @param context the current FacesContext
   * @param url an URL (which may already contain query parameters)
   */
  public abstract String encodeCurrentPageFlowScopeURL(
     FacesContext context,
     String url);
  
  /**
   * Encode the page flow scope into the dialog URL
   * 
   * Note that the Dialog Framework may first call ViewHandler.getActionURL(), which in turn will 
   * call encodeCurrentPageFlowScopeURL(). Then this method will be given a chance to encode any dialog-specific 
   * information. The dafault implementation does not modify the URL. 
   * 
   * @param context the current FacesContext
   * @param url an URL (which may already contain query parameters)
   * @return encoded URL
   */
  public String encodeDialogPageFlowScopeURL(
     FacesContext context,
     String url)
  {
    return url;
  }
}