SWF 2.0 - Backtracking and exception catching

[sai571]

I would love to have this feature developed. Voted in JIRA for tracker https://jira.springsource.org/browse/SWF-727

[sai571]

That's smart! This can work for most purposes.

[prithvi10089]

Hi Keith!

I'm using Spring Web Flow 2.3.0 and JSF 1.2.
Double-clicking on any button or hyperlink and back-navigating lead to snapshot not found exception.
In order to overcome it I edited max-execution-snapshots to -1 and made all the flow variables serializable and it worked.
But serializing flow variables is not an easy task thanks to non-serializable data members.
Could you please suggest how the exception handling method discussed here can be adopted as I'm using JSF.

[Kent Damgaard]

We were experimenting with something along the same lines

<transition on-exception="org.springframework.webflow.execution.repository.FlowExecutionRestorationFailureException" to="${flowScope.previousViewState}" />

But it did not seem to work. Should this be possible in global transitions?

[Kent Damgaard]

In the end we managed to use the Spring MVC exception handling to handle the problem. It seems to have en advantage over the previously suggested solution in that it does not require any specific java class to work

    <!-- Exception handling -->
    <bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <property name="defaultErrorView" value="error/exception" />
        <property name="defaultStatusCode" value="500" />
        <property name="warnLogCategory" value="WARN" />
        <property name="exceptionMappings">
            <props>
                <prop key="org.springframework.webflow.execution.repository.FlowExecutionRestorationFailureException">error/backbutton</prop>
            </props>
        </property>
    </bean>

on the backbutton page we present the user with an error message and a javascript-link that takes them back to the previous page.