Re: Thoughs on the camel dsl for 2.x

[Christian Schneider <ch...@die-schneider.net>]

Hi Harian,

how about generating the dsl from maven inside the user´s project. Each 
camel module that is referenced could offer extensions to the DSL. Then 
in the generate sources phase a DSL could be constructed that includes 
all camel and even user modules that contribute to the DSL. I think this 
late DSL generation is the only way to bring extensibility to Java 
Fluent Builders. I am not so sure about the disadvantages of this attempt.

Greetings

Christian

Hadrian Zbarcea schrieb:
> Camel has this wonderful discovery mechanism for RouteBuilders, 
> TypeConverters, Languages, etc. so if one uses Camel she only needs to 
> write her code, drop it somewhere on the classpath and... everything 
> works.
>
> The only main thing that's not really pluggable is the DSL.  The 
> concept of a DSL supported for multiple languages is unique to Camel 
> afaik and quite a powerful one.  However:
> * it is hand-crafted and this led to quite a few inconsistencies 
> between java, xml, scala, etc.
> * the dsl is not supported in a few languages yet, such as python, 
> ruby (expressions are supported though)
> * the ProcessorType has become huge
> * it's increasingly difficult/annoying to add support for a new 
> pattern, because this changes the API
> * does not support user-defined pattern, a user is pretty much stuck 
> with using a processor or bean, but cannot extend the language
> * does not support alternate dsl(s) in the same language, such as 
> java.  The processors are very powerful, and one could envision using 
> a different language (say something like bpel), to assemble them and 
> get the desired behavior.
>
>
> I think the biggest hurdle is I think the fact that we must support 
> smart completion in the ide(s) and java is not a dynamic language.  I 
> would like to investigate the idea of patterns being *described* in a 
> language (such as xml, or some other grammar) and then generate the 
> dsl.  I think it should be feasible, based on the fact that there are 
> not many concepts needed to describe a pattern (as a black box) and 
> the generated dsl could be built once (maybe packaged as a separate 
> jar) and reused.
>
> Your thoughts highly appreciated.
> Hadrian
>


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Christian Schneider
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http://www.liquid-reality.de