Spring Webflow Plugin

Name	Spring Webflow Plugin
Publisher
License	Open Source (ASL2)
Version	1.0.3 Production
Compatibility	Struts 2.0.6+
Homepage	http://code.google.com/p/struts2webflow/
Download	http://code.google.com/p/struts2webflow/downloads/list

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Overview

The Spring Webflow plugin INLINE

integrates Spring Webflow (SWF) with Struts 2

. It allows Struts 2 to execute spring webflows and allows spring webflows to have Struts 2 actions as webflow actions. There is also a sample car insurance app that illustrates usage of the plugin.

Features

Allows Struts 2 to execute spring webflows
Allows Struts 2 actions to be invoked by spring webflow.
Includes an interceptor that injects flow scope properties into Struts 2 actions.
Includes an annotation-based interceptor that injects flow scope properties into Struts 2 actions.
SWF flow execution key can be managed in the session rather than as a hidden field on the client.

Requirements

Spring 2.0+
Spring Webflow 1.0+
Struts 2.0.6+
Struts2Webflow 1.0.3+

Installation

See http://code.google.com/p/struts2plugin-maven-repo/ if you use maven.

For non-maven users, this plugin can be installed by copying the plugin jar into your application's /WEB-INF/lib directory.

Getting Started

Prerequisite

For background information on the core Spring Webflow concepts, visit http://www.ervacon.com/products/swf/intro/.

Step 1 - Create your flow definition xml

<?xml version="1.0" encoding="UTF-8"?> <flow xmlns="http://www.springframework.org/schema/webflow" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/webflow http://www.springframework.org/schema/webflow/spring-webflow-1.0.xsd"> <start-state idref="ageEnter" /> <view-state id="ageEnter" view="ageEnter"> <transition on="submit" to="AgeSave" /> </view-state> <view-state id="ageEnterJSP" view="ageEnter"> <transition on="input" to="enterAgeJSP" /> <transition on="submit" to="AgeSave" /> </view-state> <action-state id="AgeSave"> <action bean="struts2FlowAdapter"/> <transition on="input" to="enterAgeJSP" /> <transition on="success" to="calcRate" /> </action-state> <view-state id="calcRate" view="calcRate"> <transition on="finish" to="finish" /> </view-state> <end-state id="finish" view="finish"/> </flow>

Step 2 - Configure Spring's applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:flow="http://www.springframework.org/schema/webflow-config" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/webflow-config http://www.springframework.org/schema/webflow-config/spring-webflow-config-1.0.xsd">  <flow:executor id="flowExecutor" registry-ref="flowRegistry"> <flow:execution-attributes> <flow:alwaysRedirectOnPause value="false"/> </flow:execution-attributes> </flow:executor>  <flow:registry id="flowRegistry"> <flow:location path="/WEB-INF/flows/**-flow.xml"/> </flow:registry> <bean id="struts2FlowAdapter" class="com.googlecode.struts2webflow.Struts2FlowAdapter"></bean> </beans>

The Struts2FlowAdapter allows a Struts 2 action to execute a webflow action-state. The Struts2FlowAdapter uses the id of the action state as the name of Struts 2 action to execute. The alwaysRedirectOnPause is disabled because whether to redirect or not is easier to control in the Struts 2 configuration files.

Step 3 - Add SWF interceptors to Struts's struts.xml configuration file

The SessionFlowExecKeyInterceptor puts the flow execution key in the session rather than having it as a hidden field on the form that submitted back. The AnnotationFlowScopeInterceptor uses annotations to bind Struts 2 action variables to and from flow scope. Before an action executes, this interceptor looks for @FlowIn annotated properties of the Struts 2 action and populates the these actions from flow scope. After the action has executed, properties annotated with the @FlowOut annotation are put back into flow scope.

Step 4 - Configure the FlowAction so Spring Webflows can be executed

<action name="FlowAction" class="com.googlecode.struts2webflow.FlowAction"> <interceptor-ref name="sessionFlowExecKey" /> <interceptor-ref name="defaultStack" /> <param name="flowId">rating-flow</param> <result name="ageEnter" type="redirect"> AgeEnter.action </result> <result name="ageEnterJSP">/example/enterage.jsp</result> <result name="calcRate" type="redirect"> CalcRate.action </result> <result name="finish">/example/finished.jsp</result> </action>

For each view-state defined in the flow xml definition, there should be a corresponding result entry in the FlowAction definition. (Or a global result for that view-state)

Step 5 - Access the flow

The flow can now be launched by accessing the FlowAction.

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