ViewPreparer / concurrency issue

[Nino Ulsamer <ni...@wevade.de>]

Hello everybody,
I have a question concerning the ViewPreparer of tiles 2.
We are using the preparer to switch the "content" attribute of a couple of
tiles-definitions based on a value stored in the session. Basically we have
multiple companies with different layouts using the same system and I want
to select the corresponding template based on the company.

Everything works perfectly, I do something like the following:

ViewPreparer.execute(TilesRequestContext, AttributeContext){
  (...)

attributeContext.getAttribute("content").setValue("/path/to/some/page.jsp");
}

Now the problem is the following: I thought the preparer is used to prepare
the current rendering of a tiles definition. However, when the preparer is
executed the second time, the "content" attribute still has the new value
that was set when it was executed the first time (so
"/path/to/some/page.jsp"), not the original value!
Okay, this may or may not be a problem. I can simply overwrite the value to
its default value again or to some other value to be used this time.

But what about concurrency issues? I imagine two almost simultaneous
pageviews of two different companies. Can I assume that one rendering
process (i.e. ViewPreparer.execute() - <tiles:insertAttribute
name="content"> - sequence) will not be interrupted by another such process?
Because that could potentially mess things up seriously.

I hope someone knows the answer to that. Maybe my approach using a
ViewPreparer is not the best at all anyways? I am using a framework on top
of Spring / Struts / Tiles, and for me right now this was the easiest
solution.

Hopefully someone can help,
Thanks!
Nino

Re: ViewPreparer / concurrency issue

[Nino Ulsamer <ni...@wevade.de>]

Hi Antonio,

that is what I would have expected. I am using version 2.0.7. Tiles is
integrated into Spring 2.5.6 using the
org.springframework.web.servlet.view.tiles2.TilesConfigurer if that is
relevant.

best regards,
Nino


On Fri, Jun 19, 2009 at 7:43 PM, Antonio Petrelli <
antonio.petrelli@gmail.com> wrote:

> 2009/6/19 Nino Ulsamer <ni...@wevade.de>
>
> > Now the problem is the following: I thought the preparer is used to
> prepare
> > the current rendering of a tiles definition. However, when the preparer
> is
> > executed the second time, the "content" attribute still has the new value
> > that was set when it was executed the first time (so
> > "/path/to/some/page.jsp"), not the original value!
>
>
>
> Strange, the attribute context that arrives to the preparer is a "copy" of
> the original definition.
> What version of Tiles are you using?
>
> Antonio
>



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Nino Ulsamer
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Re: ViewPreparer / concurrency issue

[Antonio Petrelli <an...@gmail.com>]

2009/6/19 Nino Ulsamer <ni...@wevade.de>

> Now the problem is the following: I thought the preparer is used to prepare
> the current rendering of a tiles definition. However, when the preparer is
> executed the second time, the "content" attribute still has the new value
> that was set when it was executed the first time (so
> "/path/to/some/page.jsp"), not the original value!



Strange, the attribute context that arrives to the preparer is a "copy" of
the original definition.
What version of Tiles are you using?

Antonio

Re: ViewPreparer / concurrency issue

[Nino Ulsamer <ni...@wevade.de>]

Hi Antonio,
thanks for your reply - I created an issue in JIRA:

https://issues.apache.org/struts/browse/TILES-429

best regards,
Nino


On Sat, Jun 20, 2009 at 1:23 PM, Antonio Petrelli <
antonio.petrelli@gmail.com> wrote:

> 2009/6/19 Nino Ulsamer <ni...@wevade.de>
>
> >
> >
> attributeContext.getAttribute("content").setValue("/path/to/some/page.jsp");
> > }
>
>
>
> Well, it seems that the attribute maps are not copied deeply: the map
> containing the name/attribute pairs is copied, but the compound attributes
> are not copied!
>
> Can you open a JIRA issue along with a test case, please?
>
> Thanks
> Antonio
>

Re: ViewPreparer / concurrency issue

[Antonio Petrelli <an...@gmail.com>]

2009/6/19 Nino Ulsamer <ni...@wevade.de>

>
> attributeContext.getAttribute("content").setValue("/path/to/some/page.jsp");
> }



Well, it seems that the attribute maps are not copied deeply: the map
containing the name/attribute pairs is copied, but the compound attributes
are not copied!

Can you open a JIRA issue along with a test case, please?

Thanks
Antonio