W3C home > Mailing lists > Public > xproc-dev@w3.org > November 2010

RE: How to run unconnected steps in sequence?

From: <vojtech.toman@emc.com>
Date: Mon, 1 Nov 2010 08:25:23 -0400
Message-ID: <997C307BEB90984EBE935699389EC41C029E15DF@CORPUSMX70C.corp.emc.com>
To: <xproc-dev@w3.org>
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

Received on Monday, 1 November 2010 12:27:32 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 1 November 2010 12:27:32 GMT