Parameterized Workflows

Running Parameterized Workflows

Launch the Astrogrid Workbench, and then select

Modules > UserInterface > Parameterized Workflows > Run

after logging in, you will be presented with a list of the available parameterized workflows. Choose one, and fill in the parameters.

Format

A parameterized workflow is a normal workflow document which starts with a processing-instruction of form

<?parameterized-workflow

_content_

?>

The processing instruction contains an embedded xml document that documents the parameterized workflow, lists the parameters it takes, etc. The embedded xml document follows the the version 10 registry schema, where the entry must contain a CeaApplicationDescription See http://www.astrogrid.org/maven/docs/HEAD/astrogrid-workflow-objects/schema/VOCEA.html#element_CeaApplication

In addition, Application Description should have only one 'interface' element.

There's an example of a parameterized workflow attached to this page test-workflow-template.xml that doesn't do anything useful, but illustrates the format a template should take.

Index of Parameterized Workflows.

Attached to this page there is an index.xml document index.xml that acts as an index of available parameterized workfloes - it lists their URLs. This file is downloaded by the launcher application on startup.

For convenience, I've attached the parameterized workflow documents to this wiki page too - however, this is not necessary, they only need to be at some publically-accissible URL.

so silvia's solar movie maker workflow is http://wiki.astrogrid.org/pub/Astrogrid/ParameterizedWorkflows/timemovimakernew.wf

the two supporting adql query documents are also attached to this page.

Altering an existing parameterized workflow

To make changes to an existing parameterized workflow, grab the file, edit, and then upload a new version of that attachment.

Relaunch the workbench, and it'll grab the latest index.xml - test-run the workflow to verify your changes.

Publishing a new parameterized workflow

When writing a paramererized workflow, bear in mind the following constraints - Parameters must:

• • only be simple scalar values - no lists, documents,
  • only be required parameters - no optional or repeated values
  • be known before execution of the workflow - no interactivity once the workflow is being executed
  • preferably values known to the user (i.e. ra,dec) - not hard-to-know values like myspace references, registry keys.

To publish a new parameterized workflow:

• copy the format of an existing parameterized workflow
• edit the processing instruction so that it contains correct metadata for the workflow parameters
• parameter values can be referenced as normal script variables in the workflow body.
• add the new workflow as another attachment to the wiki page.
• edit the index file to include the url of the new workflow.
• Relaunch the workbench, and it'll grab the latest index.xml - verify that the new workflow appears in the list, and test-run it.

Further Work

• Allow more complex parameter types in parameterized workflows - i.e. the full range that can be specified in an ApplicationDescription
  • repeated parameters
  • optiona parameters
  • Indirect parameters - i.e. references to contents of files in myspace.

-- NoelWinstanley - 03 Mar 2005

Document History

Moved from AG2 Wiki - and updated to reflect facts now. -- NoelWinstanley - 23 Mar 2005

Edited out the implementation plan, leaving the how-to-do bits. -- NoelWinstanley - 09 May 2005

• index.xml: Removed old redshift maker.

• redshiftmakerng.xml: Removed hyperz until bug fixed.

• conesearchlist.wf: Cone search for a list of objects

• index.xml: Added cone search for a list of objects.

• conesearchlist.wf: Cone search for a list of objects

• conesearchlist.wf: Cone search for a list of objects

• sdss-dr5.xml: SDSS DR5 Simple Query

• index.xml: Added DR5 query.