Question

What is the proper way to pass a model object used in Spring Web Flow to a Controller?

My use case is as follows:

I have a flow and the end state displays a model object that contains some calculated results. That works good. I also have a link on the page to generate a pdf to display the results. That too works fine if I manually set the model object.

So how do I get the model object used in the flow to the controller? Or is there a cleaner way to view pdfs using webflow?

Thanks

Answer 1

@John V. thank you your post did help me in the right direction. This is what I have working now:

in my flow.xml

<view-state id="summary" view="summary.jsp">
    <on-entry>
        <set name="result" value="conversationScope.result" />
        <evaluate expression="printPDF" />
    </on-entry>
    <transition on="startOver" to="startOver" />
</view-state>

in my webflowContext.xml file

<bean id="printPDF" class="com.example.actions.PrintPDF"/>

PrintPDF.class

public class PrintPDF extends AbstractAction {

    @Override
    public Event doExecute(RequestContext context) {

        Result obj = (Result)context.getFlowExecutionContext().getConversationScope().get("result");
        HttpServletRequest req = (HttpServletRequest) context.getExternalContext().getNativeRequest();
        req.getSession().setAttribute("result", obj);
        return success();
    }

}

in my controller

@RequestMapping(method=RequestMethod.GET, value="/pdf")
public ModelAndView showPDF(ModelMap model, HttpServletRequest request) {
    Result result = (Result)request.getSession().getAttribute("result");
    model.addAttribute("result", result);
    return new ModelAndView("PDF", model);
}

PDF is defined as a bean in my spring-pdf-views.xml file

<bean id="PDF" class="com.example.view.PDF">
    <property name="url" value="/pdf/example.pdf" />
</bean>

That class contains the following:

public class PDF extends AbstractPdfStamperView {

    @Override
    protected void mergePdfDocument(Map<String, Object> model, PdfStamper stamper, 
            HttpServletRequest request, HttpServletResponse response) throws Exception {

        Result result = (Result)model.get("result");

        AcroFields form = stamper.getAcroFields();
//map form fields

and finally the jsp has a link like

<a href="/pdf.html">

I hope that can help someone else. I am not sure if that is the most efficient way of doing it but I am open to any suggestions.