Matthew,

You don't say where you pipeline is used, but remember: XPL is
executed using a lazy evaluation model, i.e. if a processor has one
connected output and that output is not read, the processor doesn't
even run. This is alluded to in the tutorial:

"It is important to note that the execution ordering of processors
 within a Presentation Server pipeline follows the principle of lazy
 evaluation. This means that what's important in a pipeline is its
 final result, and this same algorithm is applied when determining the
 execution order of the processors within a given pipeline. This means
 that Presentation Server always looks at the serializers and output
 parameters first. This approach may look nonintuitive at first, but
 it allows for many processing optimizations. For example, it does not
 make sense to execute an XSLT transformation if nobody is using its
 output document!"

It is correct that you can create a pipeline with any names for inputs
and outputs. But then, somebody must read those outputs, if you want
the connected processors to execute. I suspect nobody reads the
"outcome" output of your pipeline, but somebody reads its "data"
output. If you pipeline is an action, model, or view of the PFC,
that's going to be the case. This is also explained in the Tutorial:

"In general, pipelines can have zero or more inputs and zero or more
 outputs, each arbitrarily named. However, within the context of the
 page flow, as we are discussing here, a pipeline that wishes to
 participate as a model within the Presentation Server page flow
 architecture must adhere to specific conventions regarding the number
 and name of inputs and outputs. In the context of the page flow
 controller file, pipelines must:

 * Pipeline inputs: Exactly 0 or 1 input can be declared. The only
   input available to the pipeline will be the page's XForms instance
   document. To access this document, you must first declare a single
   pipeline input called instance, which is declared as follows:
   <p:param name="instance" type="input"/>. A processor in the
   pipeline that reads from this input will receive the filled-in
   XForms instance created after the user has submitted the form for
   the page.

 * Pipeline outputs: Exactly 0, 1, or 2 outputs can be declared.

   * A model with 0 output exists for side-effect reasons only, for
     example recording an entry in a log. It does not pass data to the
     page view.

   * If the model does want to pass data to the view, it must declare
     an output called data, which is declared as follows: <p:param
     name="data" type="output"/>. XML that is output by a model
     pipeline on its data output will be automatically connected to
     the view's data input.

   * In some cases, a model needs to modify the XForms instance before
     the view accesses it. In this case, the model should declare an
     output called instance, which is declared as follows: <p:param
     name="instance" type="output"/>."

I hope this helps,

-Erik

Matthew J. Graham wrote:
> Hi,
>
> I am somewhat confused about pipeline outputs; the documentation leads
> me to believe that I can create a pipeline output with any name I want so:
>
> <p:config>
> <p:param type="output" name="outcome"/>
>
> and then to connect to this I just use a ref:
>
> <p:processor name="oxf:identity">
> <p:input name="data" href="#somedocument"/>
> <p:output name="data" ref="outcome"/>
> </p:processor>
>
> but when I do this, I get no output. Instead it seems that I have to do:
>
> <p:param type="output" name="data"/>
>
> <p:processor name="oxf:identity">
> <p:input name="data" href="#somedocument"/>
> <p:output name="data" ref="data"/>
> </p:processor>
>
> so the name of the output type p:param must match the name of p:output
> which is referring to it (via ref)?
>
> Cheers,
>
> Matthew



-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/
_______________________________________________
orbeon-user mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/orbeon-user

Reply via email to