Pipeline support

[Juan José Vázquez Delgado <ju...@gmail.com>]

Hi all,

After some work, the pipeline support prototype [1] has ended up as follows:

1. A XML pipeline is expressed as a W3C XProc [2] file with "xpl" extension.
For instance:

<p:pipeline xmlns:p="http://www.w3.org/ns/xproc">

   <p:xslt>
       <p:input port="stylesheet">
           <p:document href="/xpl-sample/xsl/test-content.xslt"/>
</p:input>
  </p:xslt>


   <p:xslt>
      <p:input port="stylesheet">
          <p:document href="/xpl-sample/xsl/test-html.xslt"/>
      </p:input>
  </p:xslt>

</p:pipeline>

2. The pipeline (xpl file) is interpreted by a scripting engine named
"XProc" or  "XML pipeline processor".

3. The XProc script engine relies on Cocoon 3 Pipeline in order to setup and
execute the pipeline.

4. A Cocoon generator named SlingGenerator is responsible for preparing the
input data.

In order to get the initial XML for the pipeline, the generator tries to
resolve the current resource as:

* a XML file (adapting to InputStream)

* dynamically generated XML (using an inclusion procedure)

* the underlying node´s export document view

5. A Cocoon transformer named SlingTransformer is responsible for resolving
XSLT templates.

If you are agree with this approach, I´d like grabbing the stuff into trunk
after adding some unit testing.

The question is, where?, "bundles/scripting" or "contrib/scripting"?.

WDYT?.

BR,

Juanjo.

[1]
https://svn.apache.org/repos/asf/incubator/sling/whiteboard/jvazquez/org.apa
che.sling.scripting.xproc
[2] http://www.w3.org/TR/xproc/

Re: Pipeline support

[Juan José Vázquez Delgado <ju...@gmail.com>]

> This has been extracted from the XProc candidate recomendation [1].

Sorry, I forgot the link:

[1] http://www.w3.org/TR/xproc/

Re: Pipeline support

[Bertrand Delacretaz <bd...@apache.org>]

On Tue, Mar 10, 2009 at 10:43 AM, Juan José Vázquez Delgado
<ju...@gmail.com> wrote:
>>> ...1. A XML pipeline is expressed as a W3C XProc [2] file with "xpl" extension....
>>
>> Is this "xpl" extension standard?
>> If you're choosing your own I'd prefer not having an L at the end as
>> it's too easy to confuse with a I.
>> Maybe "xpr" or even "xproc", clearer?
>
> This has been extracted from the XProc candidate recomendation [1].
> Literally: "The media type for pipeline documents is application/xml.
> Often, pipeline documents are identified by the extension .xpl."

Fine then, let's go with the standard!
-Bertrand

Re: Pipeline support

[Juan José Vázquez Delgado <ju...@gmail.com>]

>> ...1. A XML pipeline is expressed as a W3C XProc [2] file with "xpl" extension....
>
> Is this "xpl" extension standard?
> If you're choosing your own I'd prefer not having an L at the end as
> it's too easy to confuse with a I.
> Maybe "xpr" or even "xproc", clearer?

This has been extracted from the XProc candidate recomendation [1].
Literally: "The media type for pipeline documents is application/xml.
Often, pipeline documents are identified by the extension .xpl."

I suppose we are not forced to use this extension but IMHO it could be
a good idea to stay in line with the recomendation. Anyway, we can
support both of them.

>> ...If you are agree with this approach, I´d like grabbing the stuff into trunk
>> after adding some unit testing...
>
> +1
>
>> ...The question is, where?, "bundles/scripting" or "contrib/scripting"?.
>
> We recently said "everything new initially goes under contrib", I
> think that's good in this case.
> Although very useful, this is not core Sling functionality.

Agreed.

BR,

Juanjo.

Re: Pipeline support

[Bertrand Delacretaz <bd...@apache.org>]

Hi Juanjo,

On Tue, Mar 10, 2009 at 9:47 AM, Juan José Vázquez Delgado
<ju...@gmail.com> wrote:
> ...After some work, the pipeline support prototype [1] has ended up as follows:...

Cool stuff! Still haven't tested it, shame on me...but your
description looks great.
Just two quick comments for now.

> ...1. A XML pipeline is expressed as a W3C XProc [2] file with "xpl" extension....

Is this "xpl" extension standard?

If you're choosing your own I'd prefer not having an L at the end as
it's too easy to confuse with a I.
Maybe "xpr" or even "xproc", clearer?

> ...If you are agree with this approach, I´d like grabbing the stuff into trunk
> after adding some unit testing...

+1

> ...The question is, where?, "bundles/scripting" or "contrib/scripting"?.

We recently said "everything new initially goes under contrib", I
think that's good in this case.
Although very useful, this is not core Sling functionality.

-Bertrand