cocoon-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Reinhard Poetz <>
Subject Re: More problems with implementing servlet services
Date Tue, 15 May 2007 11:02:34 GMT
Daniel Fagerstrom wrote:
> Reinhard Poetz skrev:
>> Daniel Fagerstrom wrote:
>>>> hmm, the "src" attribute of generators desribes, what is feed into 
>>>> the component. In the case of a servlet service generator, the 
>>>> output stream of a servlet is used as stream input.
>>> Rather something that is transformed to SAX output.
>>>> The "data" parameter defines the content that is passed to the 
>>>> servlet service. IMO that's not the starting point of the generator.
>>> IMO it is ;)
>>> The normal case:
>>> Source ==[octet stream]==> Generator ==[SAX]==> ...
>>> Servlet service generator as I see it:
>>> Source ==[octet stream]==> Generator ==[SAX]==> ...
>>>                              |  ^
>>>                              v  |
>>>                         ServletService
>>> As you can see, the connection to the servlet service is something 
>>> that differ from the ordinary generator usage, and because of that it 
>>> is natural to put it in a parameter.
>> :-) yes, technically that's of course right but from a user's POV the 
>> generator uses a servlet service as source.
> I don't see how a user would gain anything in having a faulty conceptual 
> view of what the component does or why we should add to the potential 
> confusion by having a non consistent use of the source attribute.
> The src attribute is used for reading from a source in all other cases, 
> using it for posting would be really confusing from a user POV ;)

Actually the code uses the input stream of the called pipeline:

SourceUtil.parse(saxParser, this.servletSource, super.xmlConsumer);

Source inputSource;
try {
   try {
     servletSource = (PostableSource)resolver.resolveURI(service);
   } catch (ClassCastException e) {
     throw new ProcessingException("Resolved '" + service + "' to source that
     inputSource = super.resolver.resolveURI(src);

} catch (SourceException se) {
     throw SourceUtil.handle("Error during resolving of '" + src + "'.", se);

IOUtils.copy(inputSource.getInputStream(), servletSource.getOutputStream());

>> The data is the payload added to the request and only the _indirect_ 
>> source for the calling pipeline.
> This is really a technical POV, and no, there is nothing _indirect_ in 
> this particular use of the src attribute.

By "indirect" I mean that in your example, the src attribute of the servlet 
service generator specifies not its own source but the source of the generator 
of the called pipeline. See the last statement.

I think the problem here is that we have two sources and depending on the 
context, one is the "main" source. But if it's only me having this view on that, 
I won't argue for it any more.

Any other opinions?

Reinhard Pötz           Independent Consultant, Trainer & (IT)-Coach 

{Software Engineering, Open Source, Web Applications, Apache Cocoon}


View raw message