Re: Modifying data models within the template

A bit of poking around shows that the default ObjectWrapper wraps Maps 
in a SimpleHash, and the SimpleHash copies the map. That's the answer to 
question #2. Is there an easy way to get it to stop doing this?

Making a copy of every hash in the system strikes me as an unnecessary 
performance killer.




On 7/7/2011 4:18 PM, Chris wrote:
> We need to give [#includes] and subpages their own datamodels to keep
> things modular. The scheme I've come up with is to create a directive
> that can be included at the top of each template that will add that
> template's data to the top-level data model.
>
> Two questions:
>
> 1. This is an explicit violation of the "data models are read-only" rule
> described here:
>
> http://freemarker.sourceforge.net/docs/pgui_misc_multithreading.html
>
> If a new datamodel is created for each page fetch, is this a problem?
> I'm running in a servlet environment. So far as I can tell, only the
> thread that is processing the page will ever see this data model.
>
> 2. When I use a HashMap as the main "root" data model, the scheme fails.
> The template says that the variables I've added to the model do not
> exist. The scheme *works* when I have the root HashMap point to an
> object, and then I replace the value of that object. There's something
> about adding a new key to the HashMap during template processing that
> the system doesn't like.
>
> Is the template processing code playing games with my HashMap, like
> making a copy? Why?
>
>
> ------------------------------------------------------------------------------
> All of the data generated in your IT infrastructure is seriously valuable.
> Why? It contains a definitive record of application performance, security
> threats, fraudulent activity, and more. Splunk takes this data and makes
> sense of it. IT sense. And common sense.
> http://p.sf.net/sfu/splunk-d2d-c2



------------------------------------------------------------------------------
All of the data generated in your IT infrastructure is seriously valuable.
Why? It contains a definitive record of application performance, security 
threats, fraudulent activity, and more. Splunk takes this data and makes 
sense of it. IT sense. And common sense.
http://p.sf.net/sfu/splunk-d2d-c2