Re: How to build a Custom Include method?

Wednesday, July 30, 2008, 7:12:09 PM, Jeremy Chone wrote:

> Thanks all for the response. This helps a lot, I think I have everything I need.
>
> Here are my quick answers to some of your points:
>
> To JR about TemplateLoader: Yes, usually the right way of doing
> this would be a template loader. However, in my case the template
> can depend on many other states that cannot easily be encoded in a
> simple string.  For example, I might choose a different template
> depending of the httpSession states (or cookies values) or from
> where the template is being included included. 
>
> To Attila about getEnvironment: This is perfect. I will get the writer from the Environment.
>
> To Daniel about TemplateDirectiveModel: Cool, makes total sense,
> TemplateDirectiveModel is what I need. Is that equivalent to
> creating a macro?

I should be, but in 2.3.x positional parameter passing (like
<@foo 1 2 /> instead of <@foo x=1 y=2 />) is not supported for them,
as the parameters are received with a Map. Starting from 2.4 it's solved
with Java 5 annotations. I think it would really be good to backport
that... but as we can't require Java 5 for 2.3.x, it would be tricky.
But really, Jonathan, can't we add an interface for the same purpose?
Then it would be usable in 2.3.x as well.

> I assume I use the Configuration.setSharedVariable method.

That's a possible approach. Another one is to put it into an
#import-able/#include-able file, like if it were a macro. That's
possible as <#assign foo = "com.example.FooDirective"?new()>.

> Jeremy,
>
>
>
>
> On Wed, Jul 30, 2008 at 3:54 AM, Daniel Dekany <[email protected]> wrote:
> Wednesday, July 30, 2008, 7:12:31 AM, Jeremy Chone wrote:
>
>> Hi,
>>
>> I would like to build a custom include method. Basically, I would
>> like to be able to call something like:
>>
>> ${customInclude(param1,param2)}
>>
>> which will include a template almost as a traditional [#include
>> does. There are two main differences between this customInclude and
>> a traditional freemarker include:
>>
>> 1) customInclude add another level of indirection to get to the
>> template name (handled by java business objects)
>>
>> 2) Each customInclude might have a different model.
>>
>> Today, I have an implementation that works. Basically, I
>> implemented an TemplateMethodModelEx method (customInclude)
>
> It should be a TemplateDirectiveModel, not a TemplateMethodModelEx.
> Thus it is to be called as <@customInclude param1 param2 />, not as
> ${customInclude param1 param2}. Directives are for output
> progressively and without escaping. Interpolations (${...}) are to
> insert the result of simpler expressions, possibly escaped. Anything
> you do with ${...} should not have a side-effect, so it should fiddle
> with the output Writer. Like consider what would happen with your
> solution here: <#assign s = "The output is: ${customInclude(...)} ">.
> It wouldn't work correctly, "s" would be "The output is: ", etc.
>
>> which implements the logic to get the template name, and get the
>> "Writer" object from the param. Then, I just get the template and
>> call template.process with the givent Writer.
>
> (The Writer can be get as the others has already told... your
> customInclude method could be called directly by the users.)
>
>> It's ugly, but it work. I hide this method with a macro, so, as the
>> pages do not have too now about the Writer object/param.
>>
>> Is there better way for doing this? Can I get some more context in a TemplateMethodModelEx method ?
>>
>>
>> Jeremy,
>
> --
> Best regards,
>  Daniel Dekany
>
>
>

-- 
Best regards,
 Daniel Dekany


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