sharing data between render() and processAction() method

[hubertg]

Hi,

I need to share data between the render() and the processAction() method.

The method of (my) choice (and I think the only? method) is using the PortletSession:

render() :

request.getPortletSession("sharedData", value);

processAction();

Object data = request.getPortletSession("sharedData");
// do something with data

my question is now:

is there anything problematic about sharing data via the PortletSession?

I could think of problems because of the fact that the processAction and the render request are seperate http requests. is there the possibilty that a 3rd render request comes between these two?

something like that
REQUEST 1
portletX.processAction()
---------------------------------------<<<< REQUEST 3 ???
---------------------------------------<<<< portletX.render();
---------------------------------------<<<< portletY.render();
---------------------------------------<<<< portletZ.render();
REQUEST 2 (because of server redirect)
portletX.render()
portletY.render()
portletZ.render()

I would be very happy if someone could bring some light into this, although i'm not sure, if I made myself clear ...

thanks in advance.

[hubertg]

correction:
of course i meant

request.getPortletSession().setAttribute("sharedData", value);

and

Object data = request.getPortletSession().getAttribute("sharedData");

an edit function would be great ... :-)

[bdaw]

for string values just use:

PortletURL url = response.createActionURL();
url.setParameter(?paymentMethod?,?creditCardInProfile?);

I'm not sure in which order you want to pass those objects.

If render --> action
Your concerns are correct. Render phase for a portlet can be triggered multiply times with unpredictable order beetween portlets on the same page and you have no influence on this.

If action --> render
You simply use ActionRequest.setAttribute(), RenderRequest.getAttribute() or ActionRequest.setRenderParameter() which is better practice than using a session

[hubertg]

thanks for your answer.

The order is:

1. processAction() portlet A
2. render() portlet A
3. render() portlet B
4. render() other portlests C,D, ...

I'm porting a MVC web framework (WebWork 1) into a portlet. The classical MVC approach is based on one atomic request-response cycle. The action class needs the input parameters, creates a ValueStack (the action's result) which is passed to the jsp pages via request attributes. In the portlet I have to split this process into two phases, namely the processAction and the render phase. Therefore I need a way to pass the ValueStack from the processAction phase to the render phase.

I think render params are no solution for my problem because first I don't want to make results directly visible for the user and second it's practically impossible to set java objects as render objects.

br, hubert

[bdaw]

you do ActionRequest.setAttribute(Object o) and RenderRequest.getAttribute(...)

Consider using MVC web framework that has bridge/support for portlets. JSF and struts has some.

And read portlet specification (jsr-168) - it's not very long and really readable ;)

[hubertg]

I may be wrong, but I think by using your suggested commands the Object o won't be accessible in the RenderRequest. If it were I'd happily use this method of sharing objects between the methods.

The only way is to use ActionResponse::setRenderParameter(String). Then the renderparameter is simply added to the url used for redirect (/portal/default/?renderparam1=value).

Render and ActionREquest are two different HTTPServletRequest and not sharing any objects. Thats at least what I remember from JSR 168 :-)

JSF and struts are no real alternatives because the current system is based on webwork 1. I used the StrutsBridge as some kind of inspiration though.

[bdaw]

arf... ok. of course your right. I wrote the anwser to fast and it is wrong. sory for that.... very stupid from my side.