Hello Paul. I didnt know anything about graphs. Thanks for explaining.
So how do you make these graphs? How do you link things in this fashion. I
am really interested. Any links you can send me about this?
----- Original Message -----
From: "Paul Speed" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, June 21, 2001 12:53 PM
Subject: Re: Opening up a thread on ALTERNATE SCOPES
> A graph is a data structure where nodes are linked together. One
> node is linked to several other nodes and so on. A directed graph is
> a graph where the links have a specific direction. A tree is a special
> form of graph (usually directed) that only branches in one direction.
> In other words, a child node will never link to something higher in
> the tree. It only branches down.
>
> For workflow types of applications the nodes of a graph often represent
> states in a workflow. The links between the nodes represent
> transitions. Sometimes these transitions also have functionality
> attached to them. It is often necessary to have circular workflows
> or workflows that transition to another step outside of the normal
> flow of the current "process". This makes a tree a poor data
> structure to use since it cannot loop back on itself.
>
> Although, I now realize that since we aren't working from the same set
> of definitions, I shouldn't have taken your "tree" reference to be so
> specific.
>
> -Paul Speed
>
> Jonathan Asbell wrote:
> >
> > Can you describe what you mean by graph. Do you mean a HashMap or List?
> > How do you "jump"? How do you go follow decisions and results?
> >
> > ----- Original Message -----
> > From: "Paul Speed" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Thursday, June 21, 2001 2:24 AM
> > Subject: Re: Opening up a thread on ALTERNATE SCOPES
> >
> > > Just one small point...
> > >
> > > In all my (admittedly brief compared to some) travels through workflow
> > > land, I've never had a workflow that was specifically tree. They all
> > > end up forming a graph at some point.
> > >
> > > One could argue that you can just have jump points from one branch to
> > > another, but in my experience, after many iterations the tree becomes
> > > more of a hinderance than a boon as jump points become more frequent.
> > >
> > > It might be better to design it to be a graph structure from the
> > > beginning.
> > >
> > > -Paul Speed
> > >
> > > Jonathan Asbell wrote:
> > > >
> > > > Since my needs are for web container persistence, let me make a
> > suggestion
> > > > in that area.
> > > > An object called WorkflowPath could be created with configurable
values
> > > > sucked up from a file. The values could be some kind of tree, like
a
> > > > decision/process tree. The WorkflowPath object would be stored in
> > > > application scope, or a custom scope as mentioned below in the
original
> > > > post, such as Sub-Application scope. When you begin a process you
grab
> > the
> > > > WorkflowPath from the scope stored under a name like
"loginWorkflow",
> > and
> > > > you would query it for the next step in the decision/process tree.
It
> > would
> > > > be nice maybe to have a pointer as to where you are in the sequence
of
> > > > things. Anyone want to add to this? Anyone want to dis this? Are
you
> > all
> > > > asleep on this warm New York Summer night? =)
> > > >
> > > > ----- Original Message -----
> > > > From: "Geir Magnusson Jr." <[EMAIL PROTECTED]>
> > > > To: <[EMAIL PROTECTED]>
> > > > Sent: Wednesday, June 20, 2001 11:25 PM
> > > > Subject: Re: Opening up a thread on ALTERNATE SCOPES
> > > >
> > > > > Jonathan Asbell wrote:
> > > > > >
> > > > > > Persistent storage is an option too. I was hoping, however to
limit
> > > > calls
> > > > > > through the enterprise parts and database.
> > > > >
> > > > > Why?
> > > > >
> > > > > > You could argue that it belongs
> > > > > > there because the database is the central location holding all
data
> > and
> > > > > > information and therefore should hold workflow info, especially
in
> > the
> > > > face
> > > > > > of changing services/activities. However, must I consult the
> > database
> > > > or a
> > > > > > db developer each time I want to add, change, or see anything?
That
> > is
> > > > a
> > > > > > time waster.
> > > > >
> > > > > Not really. I mean, I guess it's your design requirements. I
would
> > > > > want it to be that a user in a process (or a process itself) has
no
> > > > > requirement of 'immediate completion' - i.e. some part of the flow
can
> > > > > take a while.
> > > > >
> > > > > So then if the servlet container goes down, I don't care. No
state
> > > > > lost.
> > > > >
> > > > > >
> > > > > > If you were not going to use persistent storage, how would you
do
> > it?
> > > > >
> > > > > For what I want to do, i can't really escape it. Somewhere,
something
> > > > > has to remember the state - assume the servlet container is going
down
> > > > > at some point...
> > > > >
> > > > > geir
> > > > >
> > > > > > ----- Original Message -----
> > > > > > From: "Geir Magnusson Jr." <[EMAIL PROTECTED]>
> > > > > > To: <[EMAIL PROTECTED]>
> > > > > > Sent: Wednesday, June 20, 2001 10:17 PM
> > > > > > Subject: Re: Opening up a thread on ALTERNATE SCOPES
> > > > > >
> > > > > > > Can I ask why you don't go with persistant storage, like a
rdbms?
> > I
> > > > > > > have been thinking about workflow recently as well, although
not
> > > > > > > specifically w/in struts, and I believe that for the general
> > solution,
> > > > > > > where someone can come back a long time later and resume, or
be it
> > an
> > > > > > > automated process, persistant storage would be required.
> > > > > > >
> > > > > > > geir
> > > > > > >
> > > > > > >
> > > > > > > > Jonathan Asbell wrote:
> > > > > > > >
> > > > > > > > Hello all. We were talking about workflow a few weeks ago
and
> > the
> > > > > > > > conversation dissipated. I am trying to open it up again
> > because I
> > > > > > > > have found a need for more scopes, and a need to implement
these
> > new
> > > > > > > > scopes in the next few months. I am interested specifically
in
> > how
> > > > it
> > > > > > > > can be implemented in Struts. Let me begin with the new
scopes.
> > > > > > > >
> > > > > > > > 1) Workflow scope within an application
> > > > > > > > Store values from the first step until the final step and
then
> > get
> > > > rid
> > > > > > > > of the values
> > > > > > > > You could probably use an adaptor, hide implementation from
the
> > > > > > > > developer, and store this scope inside the "session" scope
> > > > > > > > Example - within an application store a value Do Activity 1,
> > then do
> > > > > > > > Activity 2, then do Activity 3, then throw out the value
> > > > > > > >
> > > > > > > >
> > > > > > > > 2) Workflow between applications (mentioned by Dan Connelly
> > earlier)
> > > > > > > > Store values from the first step until the final step and
then
> > get
> > > > rid
> > > > > > > > of the values
> > > > > > > > You could probably use an adaptor, hide implementation from
the
> > > > > > > > developer, and store this scope inside the "application"
scope
> > > > > > > > Example - store a value and do Activity 1 in Application 1,
then
> > do
> > > > > > > > Activity 2 in Application 2, then do Activity 3 in
Application
> > 3,
> > > > then
> > > > > > > > throw out the value
> > > > > > > >
> > > > > > > >
> > > > > > > > 3) Sub-Application scope
> > > > > > > > Store values that pertain to a sub-directory within an
> > application
> > > > > > > > You could probably use an adaptor, hide implementation from
the
> > > > > > > > developer, and store this scope inside the "session" or
> > > > "application"
> > > > > > > > scope though I'm not sure which would be more appropriate.
> > > > > > > > Example - Your applcation is a magazine which has 4
different
> > > > > > > > sections, and you want to store values only pertaining to
each
> > > > > > > > section. When you leave the section the value is not
visible,
> > and
> > > > may
> > > > > > > > or may not disappear (depending on what you want to do).
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > Geir Magnusson Jr.
[EMAIL PROTECTED]
> > > > > > > System and Software Consulting
> > > > > > > Developing for the web? See
http://jakarta.apache.org/velocity/
> > > > > > > You have a genius for suggesting things I've come a cropper
with!
> > > > > > >
> > > > >
> > > > > --
> > > > > Geir Magnusson Jr. [EMAIL PROTECTED]
> > > > > System and Software Consulting
> > > > > Developing for the web? See http://jakarta.apache.org/velocity/
> > > > > You have a genius for suggesting things I've come a cropper with!
> > > > >
> > >
>
