SimpleStateMachine Forum Rss Feed

New Post: Timed Events

PlasticLizard — Tue, 01 Sep 2009 15:59:02 GMT

For the timer, you would need some kind of a long running process to manage the timers, so you probably will need to implement that in whatever process is hosting your workflow and have the timer handler load your workflow and fire an event, TimeoutExpired or something. You could also do something sneaky using the .NET web cache (which is availble in all apps, not just ASP.NET apps)

http://www.codeproject.com/KB/aspnet/ASPNETService.aspx

I think I would also impelment the rule based logic srrounding the pin validation in a context or business object that provides context and events to the state machine. This particular state machine library is intended only to manage events and transitions, and leaves actually managing the state (how many times a user has failed with their pin) to the underlying business or context objects. I have considered having expression based conditional rules that can prevent or allow state transitions, but I haven't found the time to build that in. In the mean time, you can place such logic around event firing code in your business logic.

New Post: Timed Events

myersd — Thu, 27 Aug 2009 08:17:38 GMT

What would be the best way to have a timed based trigger. An example of what I mean is:

Imaging the scenario of a Call management workflow

After the call ages to being 24 hours old, its state should transition to an urgent state

A second question I have is whether or not you could have a transition being conditional upon a variable. An example of what I mean is:

Enter PIN, Validate.....if ok continue, else report invalid pin. If pin invalid 3 times, lock account.

Any ideas on both of these?

New Post: Parallel Process

PlasticLizard — Thu, 30 Apr 2009 18:30:12 GMT

That's a tough one. If you were using a sequential workflow, this would be a no brainer, you'd do a branch and join. We also have this need in our process flows, and I haven't settled on the right answer yet. Our workaround has been to handle it at a higher level, but I'm not terribly happy with our workaround, so I won't bother explaining it. Of your two options, I don't think I'd start creating states that represent combinations of other states, that sounds like a slipper slope. Instead you may want to have a single state, AwaitingDocumentResults, and this state can either host an inner state machine for each document, or can handle waiting for the responses in application logic. In the end, I think the state machine library should probably be given the ability to manage multiple child states automatically, but it will take care not to drift into re-creating WF and building a sequential workflow library into the state machine library, where it doesn't belong. Probably not a hugely helpful answer, but it's all I've got :)

New Post: Parallel Process

nirataro — Wed, 29 Apr 2009 13:13:57 GMT

I have a system that use a single column for case status. SimpleStateMachine state drives the value of this case status. So right now I have a design dillema.

I have a situation where I need to start two things at the same time. Say that the current state is DocumentsPending. Now I have to send two types of different documetns, which normal will move the state to DistrictLetterDocumentPrinted and ApprovalLetterDocumentPrinted. The next step of each of these statuses are DistrictDocumentWaitForResult and ApprovalLetterlDocumentWaitForResult.

Essentially I am sending two categories of documents to separate institution and I am waitng for both of their results to arrive before I move forward and I want the ability to check where the status of the case are at any given time.

Now should I add an additional case status column so that i can store both DistrictLetterDocumentPrinted and ApprovalLetterDocumentPrinted or should I create a third combination status which says "DOAndApprLetterPrinted" which adds 2/3 additional statuses for each combination but enable me to use just a single column.

New Post: Injecting dependencies into Tasks

k03123 — Tue, 24 Mar 2009 00:17:22 GMT

hi nirataro,

first you need to define your implementation of IObjectBuilder. I have defined mine as below:

public class WindsorObjectBuilder : IObjectBuilder
    {
        private readonly IWindsorContainer _container;

        public WindsorObjectBuilder(IWindsorContainer container)
        {
            _container = container;
        }

        public T Create<T>() where T : class
        {
            return _container.Resolve<T>();
        }

        public T Create<T>(Type type) where T : class
        {
            return _container.Resolve<T>();
        }
    }

then register it as suggested by plastic lizard:

ServiceLocator.RegisterService<IObjectBuilder>(new WindsorObjectBuilder(windsorContainer));

New Post: Injecting dependencies into Tasks

nirataro — Sun, 22 Mar 2009 08:53:57 GMT

Is there any example to do accomplish these tasks? Sorry, I'm lost with all the DI techniques being described here.

New Post: Injecting dependencies into Tasks

katokay — Sun, 01 Mar 2009 23:33:07 GMT

We do use the CommonServiceLocator. The recent release of Prism 2.0 also uses it, as well as the Caliburn beta. But yes, still asking out of curiosity.

New Post: Injecting dependencies into Tasks

k03123 — Wed, 25 Feb 2009 00:52:01 GMT

thanks a lot. it works as expected.

been busy with other stuff and couldn't try it out till today.

New Post: Injecting dependencies into Tasks

PlasticLizard — Fri, 20 Feb 2009 20:14:05 GMT

Yes, I have thought about it a few times - I wasn't sure if anyone is actually using the CommonServiceLocator, so I haven't actually bothered to make the change thus far, as I hate to take a dependency on an external library without a good reason - are you actually using CommonServiceLocator + adapters, or are you asking out of curiosity?

New Post: Injecting dependencies into Tasks

katokay — Thu, 19 Feb 2009 10:33:24 GMT

Any thoughts on adding support for CommonServiceLocator?

New Post: Injecting dependencies into Tasks

PlasticLizard — Thu, 19 Feb 2009 05:18:01 GMT

Yes, it looks like something changed. There is a service locator now (although it doesn't seem to be getting much use in the library, might have been overkill). Anyway, if you have an implementation of IObjectBuilder you want to use to create your tasks, you can register it when your app inits like this:

ServiceLocator.RegisterService<IObjectBuilder>(myObjectBuilder);

New Post: Injecting dependencies into Tasks

k03123 — Thu, 19 Feb 2009 04:00:51 GMT

i am trying to inject dependencies into Task. Here you have mentioned to pass IObjectBuilder to the constructor of StateMachine. But i see the constructor doesn't accept any parameters. Has the code changed since then or am I missing the obvious?

cheers

New Post: on_event_fired

nirataro — Tue, 17 Feb 2009 15:10:27 GMT

The feature works well - I've incorporated this to our soon to be production system - we chose this library over WF. Good work.

New Post: on_event_fired

PlasticLizard — Tue, 17 Feb 2009 05:43:05 GMT

No problem - let me know if it gives you any trouble.

New Post: on_event_fired

katokay — Mon, 16 Feb 2009 17:48:47 GMT

I was doing my usual checks to see if anything new had happened with this project and saw this. Looking forward to this change. Very much appreciated!

New Post: on_event_fired

k03123 — Mon, 16 Feb 2009 00:26:24 GMT

thanks heaps.

appreciated.

New Post: Raising event from the definition

nirataro — Sun, 15 Feb 2009 19:59:36 GMT

Brilliant. Thank you so much.

New Post: Raising event from the definition

PlasticLizard — Sun, 15 Feb 2009 05:03:35 GMT

There are a few ways to skin this cat. Probably the most straightforward would be to use the just added "event action" feature that allows actions to be fired in response to individual events, instead of simply state transitions, like this:

state @RequiredApprovalsRejected:

when @Cancel >> @Cancelled

on_event @assign_call_task "Approval Rejected", """Case {CaseNumber} approval has been rejected. Please notify to pick up original """ , 20

state @PaymentPending:

when @PayFee >> @LicensePrintingPending

when @Cancel >> @Cancelled

on_event @assign_call_task "Pay Initial Fee", """Case {CaseNumber} has pending payment. Please come to the office to pay. """ , 2

You will need to download the latest version to be able to use this feature.

New Post: on_event_fired

PlasticLizard — Sun, 15 Feb 2009 04:52:52 GMT

Better late than never, hopefully :) I just checked in support for this feature. I adopted both styles, so you can add event actions to the state machine as a whole, which means that any time that event is received at any time during the life of the state machine the defined task will be executed, or you can add an even action to a specific state, which limits the scope of the action to events received while in the specified state.

#Event Definitions

#--------------------------------------------------------

trigger @OrderPlaced

trigger @CreditCardApproved

trigger @CreditCardDenied

trigger @OrderCancelledByCustomer

trigger @OutOfStock

trigger @OrderStocked

trigger @OrderShipped

trigger @OrderReceived

trigger @OrderLost:

on_event @WriteToHistory, "Order Lost event occured. Oh No! Sorry Mr. Customer!"

##AND/OR##

state @AwaitingPayment:

when @CreditCardApproved >> @AwaitingShipment

when @CreditCardDenied >> @OrderCancelled

when @OrderCancelledByCustomer >> @OrderCancelled

on_event @WriteToHistory, "The order was cancelled prior to payment. Probably accidentally clicked 'One Click Checkout'"

New Post: on_event_fired

PlasticLIzard — Sat, 14 Feb 2009 22:19:37 GMT

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