/*
* Copyright 2004-2012 the original author or authors.
*
* Licensed 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.springframework.webflow.mvc.portlet;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.PortletModeException;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import javax.portlet.ResourceRequest;
import javax.portlet.ResourceResponse;
import org.springframework.webflow.core.FlowException;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.execution.FlowExecutionOutcome;
/**
* A controller helper used for customizing access to a <i>single</i> flow definition in a Portlet environment. This
* helper is used to:
* <ol>
* <li>Launch executions of that flow with data in the execution input map
* <li>Handle outcomes reached by that flow in a custom manner
* <li>Handle unhandled exceptions dealing with that flow in a custom manner
* </ol>
* Such a handler can be visually thought of as a "flow reference" on a Garrett IA diagram. It holds a reference to the
* flow id to launch, how to provision its input, how to process its outcomes, and how to handle uncaught exceptions.
*
* @author Keith Donald
* @author Rossen Stoyanchev
*/
public interface FlowHandler {
/**
* Returns the id of the flow handled by this handler. Used by a Controller to load the flow definition.
* @return the flow id
*/
public String getFlowId();
/**
* Creates the flow execution input map to pass to a new instance of the flow being started in a render request.
* Used by a Controller to launch the flow execution with the correct input.
* @param request the current request
* @return the input map
*/
public MutableAttributeMap<Object> createExecutionInputMap(RenderRequest request);
/**
* Creates the flow execution input map to pass to a new instance of the flow being started in a resource request.
* Used by a Controller to launch the flow execution with the correct input.
* @param request the current request
* @return the input map
*/
public MutableAttributeMap<Object> createResourceExecutionInputMap(ResourceRequest request);
/**
* Handles a specific flow execution outcome. Used to change portlet modes after the flow ends.
* @param outcome the outcome that was reached
* @param request the current action request
* @param response the current action response
* @return whether this outcome was handled, or whether the caller should handle it
* @throws PortletModeException if this handler tries to change the portlet mode to something invalid
*/
public boolean handleExecutionOutcome(FlowExecutionOutcome outcome, ActionRequest request, ActionResponse response)
throws PortletModeException;
/**
* Handles a flow exception that was not handled by the Web Flow system in render request. Used by a Controller to
* handle a specific type of exception dealing with this flow in a custom manner.
* @param e the unhandled exception originating from Spring Web Flow. May be thrown by the flow execution itself or
* the flow executor system if no execution could be restored.
* @param request the current request
* @param response the current response
* @return the name of a specific error view to render, or <code>null</code> if the exception should be handled by
* the caller
*/
public String handleException(FlowException e, RenderRequest request, RenderResponse response);
/**
* Handles a flow exception that was not handled by the Web Flow system in a resource request. Used by a Controller
* to handle a specific type of exception dealing with this flow in a custom manner.
* @param e the unhandled exception originating from Spring Web Flow. May be thrown by the flow execution itself or
* the flow executor system if no execution could be restored.
* @param request the current request
* @param response the current response
* @return the name of a specific error view to render, or <code>null</code> if the exception should be handled by
* the caller
*/
public String handleResourceException(FlowException e, ResourceRequest request, ResourceResponse response);
}