RE: How to run unconnected steps in sequence?

The solution is to introduce the dependency explicitly. Here are some examples (all are variations on the same theme, but some may be more applicable to your use case):

 

1. 

<p:store href=”file.xml” name=”store”/>

<p:load>

  <p:with-option name=”href” select=”’file.xml’”>

    <p:pipe step=”store” port=”result”/>

  </p:with-option>

</p:load>

 

2.

<p:store href=”file.xml” name=”store”/>

<p:group>

  <p:sink>

    <p:input port=”source”>

      <p:pipe step=”store” port=”result”/>

    </p:input>

  </p:sink>

  <p:load href=”file.xml”/>

</p:group>

 

3.

<p:group>

  <p:store href=”file.xml”/>

  <p:identity>

    <p:input port="source">

      <p:empty/>

    </p:input>

  </p:identity>

<p:group>

<p:group>

  <p:sink/>

  <p:load href=”file.xml”/>

</p:group>

 

Some processors also support extension attributes to control dependencies between steps, but I would recommend to avoid this unless absolutely necessary.

 

Regards,

Vojtech

 

--

Vojtech Toman

Consultant Software Engineer

EMC | Information Intelligence Group

vojtech.toman@emc.com

http://developer.emc.com/xmltech


 

From: xproc-dev-request@w3.org [mailto:xproc-dev-request@w3.org] On Behalf Of Jostein Austvik Jacobsen
Sent: Monday, November 01, 2010 1:01 PM
To: xproc-dev@w3.org
Subject: How to run unconnected steps in sequence?

 

I remember seeing a note on this problem somewhere, but I can't find it. Say I want to run these two steps in sequence:

 

<p:store href="file.xml"/>

<p:load href="file.xml"/>

 

p:load would have to run after p:store, or the file wouldn't be there yet. Since p:store has no primary output and p:load has no primary input, the processor may choose the order they are run in.

 

Is there a standard pattern for solving such issues? Something general, not just for the store/load use-case?

 

 

Regards

Jostein Austvik Jacobsen