[kepler-dev] Global access of a value among all workflow actors?

[Tristan King]

Hi guys,

For the 3rd method mentioned here:

> 3) create a standalone, static class to store the info. I did this in 
> Authentication framework. Once you get a proxy from GAMA server, you save 
> it in the static instance of ProxyManager. When you need it, you just call 
> (indirectly) ProxyManager.getProxy() from anywhere in your actors.

Just as a side note, I know nothing about how the GAMA proxy stuff, so
when I mention a proxy think of it as a connection to some kind of
service, like a SRB server.

What happens if you want to run two workflows at the same time which
connect to different proxys? Wouldn't using a static class to manage the
proxy connection prevent this?

Of course you could solve this by running multiple instances of kepler,
but that might not be a viable solution. Also, not having something
physicaly in the workflow may confuse people (although i assume there is
some kind of actor which handles any variables that may need to be
passed to the proxy manager).

I like the idea of being able to replace a number of links with this
sort of thing, the SRBConnect actor causes workflows to get quite messy
sometimes, however as Norbert mentioned I think we really need to be
careful with things like this.

One idea i've been thinking of is something like a relation, but have an
invisible link between a pair (or a set) of relations, like a
underground tunnel in the workflow, so Tokens can go in one end of the
tunnel, and come out on the other side of the workflow without
cluttering it up. it should be easy to visually indicate which relations
are connected using a numbering system of colors or something else.

I will start working on a proof of concept for this method soon.
what do you think?

-Tristan

On Thu, 2006-03-02 at 14:01 -0800, Zhijie Guan wrote:
> Hi, Nandita,
> 
> I faced the same problem when I developed the Authentication framework. I 
> heard at least three ways to solve it. I just list them here and you can 
> make your decision.
> 
> 1) Ilkay told me that we can set some variables in the director, stored 
> the information in those variables after generation,  so any 
> actor in the workflow can access it. I did not try it.
> 
> 2) I am not sure if the parameter of the workflow can be used to store the 
> info. But think any workflow as a compositActor. If you can access the 
> parameters in an actor, you should (theoretically) be able to access 
> "workflow parameters" in any actors of your workflow.
> 
> 3) create a standalone, static class to store the info. I did this in 
> Authentication framework. Once you get a proxy from GAMA server, you save 
> it in the static instance of ProxyManager. When you need it, you just call 
> (indirectly) ProxyManager.getProxy() from anywhere in your actors.
> 
> Zhijie
> 
> 
> 
> On Thu, 2 Mar 2006, Nandita Mangal wrote:
> 
> >
> > Hi there,
> >
> > Is there anyway/ possible implementaion, where given an output generated
> > from an actor, can be stored in the worfklow Parameter/ other location?.
> > And later on that value be used by mulitple actors on the same canvas?.
> > The need for this is required to avoid messy connections b/w main and
> > multiple other actors (accessing the output generated from the main
> > actor) Hence a global value / global token that can be edited and
> > accessed by a given workflow.
> >
> > Thanks,
> > Chien-Yi
> > Nandita Mangal.
> >
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> >
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-- 
Tristan King                            | Ph: (07) 4781 6911
DART project team                       | Email: Tristan.King at jcu.edu.au
James Cook University                   | Web: http://dart.edu.au
Townsville QLD 4814                     | http://plone.jcu.edu.au/dart/
Australia                               |