Re: Import macros into global namespace

Tuesday, February 8, 2011, 12:23:13 AM, Chris wrote:

>>> Is it possible to import a library of macros into the main namespace?
>>> We'd like to do this using Configuration.autoImport().
>>
>> Doesn't Configuration.setAutoIncludes do what you want?
>
> It doesn't, so far as I know. Neither
>
>      conf.setAutoIncludes(null, "mylibrary.ftl")
>
> nor
>
>      conf.setAutoIncludes("main", "mylibrary.ftl")

There is setAutoImports and then there is setAutoIncludes. What I'm
asking is if you have tried setAutoIncludes. That does the same as
#include (as opposed to #import).

> will put the macros in the main namespace. Is is possible to get them 
> into that namespace?
>
>> Maybe this can be worked around if you import the
>> macro library with a non-conflicting name, then pass the macro library
>> (the hash that #import creates) back to the data-model through a
>> custom method of the a custom data-model root class, which then uses
>> that for fall-backs. I never tried to do this, so I'm not sure if it
>> has a catch...
>
> Sounds like it might work. How do I get access to the hash that #import
> creates? And where?

So this is only interesting if you want make all the stuff uniformly
accessible with that "mynamespace" perfix (as opposed to making them
uniformly accessible without any prefix - for that see the #include
trick earlier). Regarding how to achieve this, now that I think more
about it, I think the cleanest solution is this:

  MySpecialTemplateHashModel mynamespace = new MySpecialTemplateHashModel(...);
  root.put("mynamespace", mynamespace)
  Environment env = myTemplate.createProcessingEnvironment(root, out);
  mynamespace.setDefaults(env.importLib("/include/mymacros.ftl", "iDontCare"))
  env.process();  // and only then process the template

Here you will have a "mynamespace" variable in the data-model that
contains whatever you have put into MySpecialTemplateHashModel; that's
trivial so far. The trick is that MySpecialTemplateHashModel has a
setDefaults(TemplateHashModel) method, that sets a fall-back
TemplateHashModel. Above I set it to the namespace hash that <#import
"/include/mymacros.ftl" as iDontCare> would create in FTL. This way
the two hashes don't hide each other (since "mynamespace" and
"iDontCare" are different names), instead they are merged under the
"mynamespace" name. I haven't tried this... but I'm certain this
approach will work.

-- 
Best regards,
 Daniel Dekany


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