Re: Another Idea/Question

Sunday, November 16, 2008, 7:22:25 PM, Luther Baker wrote:

> On Nov 13, 2008, at 6:53 AM, Daniel Dekany wrote:
>
>> Saturday, November 8, 2008, 6:29:38 PM, Luther Baker wrote:
>>
>>> Hope I'm not bothering anyone's time but wanted to run another idea  
>>> past you.
>>>
>>> I know that a macro can be implemented by a Java class as well as a  
>>> text template.
>>>
>>> I have a desire to do 'both' simultaneously.
>>>
>>> <snip.../>
>>> but it would still work. Is there a more elegant way to do this in  
>>> FM?
>>
>> I think the usual way of doing this is that you write the "editor"
>> macro in FTL, and then that macro calls out for the java code
>> explicitly:
>>
>> <#macro editor>
>> <#local m = macroHelpers.editor()> <#-- calls a Java method -->
>> ${m.fieldOne} ${m.fieldTwo}
>> </#macro>
>>
>> (In any case, conveniently calling a macro has much higher priority
>> than conveniently defining it, so writing <@DualMacro table/> and like
>> into your templates is most certainly a bad idea.)
>>
>> -- 
>> Best regards,
>> Daniel Dekany
>>
>
> I agree with your sentiment there at the end - but I also have an  
> ambitious goal to also make it easy to define macros. I think more  
> people will use them (at least, within my framework).
>
> To that end - I believe I can create an abstract base class to  
> encapsulate most of the arguments required to implement  
> TemplateDirectiveModel and then come up with some type of mechanism to
> invoke the end user's methods - but with reflection in such abundance
> these days - I'd much prefer a native FTL runtime lookup mechanism  
> that noticed exactly what the user implemented (conventional method  
> names or annotations) and invoked the operation as such. To that end -
> I've been able to avoid interfaces for the most part, etc. For what it
> is worth, the new Spring MVC and Tapestry annotations do just that.  
> GET and POST methods as well as arguments can be annotated and thereby
> - leverage the simple use of POJOS.
>
> No problems - that is simply what I am doing in my framework and I'm  
> trying to shoehorn FTL in as my template engine. It is working great!
> I just want to offer a very simple way for a developer to write macros
> or 'components' in Java.
>
> I've not looked at the code - but is it possible that this mechanism  
> is injected? :) That'd be easy to overwrite ... essentially, find the
> method the user wants to match up to this directive and invoke it  
> every time the directive shows up. Again, FTL is great, I'm just  
> exposing certain things in my framework and the more direct the  
> mapping to FTL, the easier is it to publish.

Well, at certain points I don't get what exactly you mean, but maybe
you should look into the topic ObjectWrapper-s. A key benefit of
FreeMarker is exactly that you can expose data (that can include
methods and directives) to templates in the way that serves your
specific goals the best. Whether you use annotations or not to drive
the wrapping decisions is up to you, but usually it's not needed.

-- 
Best regards,
 Daniel Dekany


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