Matt's Musings

Mapping WF 3 activities to WF 4

2009-06-26T19:45:00Z

First, this post is not about any automated tools for mapping your activities, so don’t get too excited. :) Instead, I wanted to take the opportunity to talk about the changes to the base activity library in the context of the activities available today in WF 3. If you are using WF today, there are some activities that have direct counterparts, while others are split into multiple activities and yet others disappear completely. Of course there are also some new activities that were not available in WF 3. In the tables below, I outline each of these different categories with some notes. Hopefully this mapping helps you see what is changing, what is new, and what goes away.

NOTE: this information is based on Beta 1 of WF 4 and some changes are possible, though nothing big is likely, between now and the RTM.

Activities with direct or indirect equivalents

WF3 Activity	WF4 Activity	Notes
Delay	Delay	The activity works the same, but the timers are handled differently in the framework.
Sequence	Sequence
Parallel	Parallel	Similar, but the internals of execution may differ slightly by RTM.
Replicator	ForEach<T>, ParallelForEach<T>, ForEach, ParallelForEach	These provide <optional> typed access to the instance data and truly declarative authoring experience. Each represents the different execution modes of the Replicator activity – so it has been split into four similar activities. I think most people will use the generic versions more than the others, but time will tell.
CallExternalMethod	InvokeMethod, InvokeMethod<T>	Provides .NET method invocation and optional return of a typed return value. This can be a call on an instance stored in a variable or a static method.
HandleExternalEvent	Receive, ReceiveAndSendReply	WCF messaging activities replace the Local communications model, even for host-> workflow communication.
Listen	Pick	The Pick activity is the primary WF4 activity that replaces the Listen and the State which were both containers for EventDriven activities.
EventDriven	PickBranch	This is an indirect mapping and you don’t use the PickBranch outside the pick, but it serves the same basic purpose of the EventDriven.
Compensate	Compensate	Though the mechanism are slightly different, the activity serves the same purpose – to execute the compensation handler for a compensable scope.
CompensatableSequence	CompensableActivity	The new activity includes a ConfirmationHandler which can execute when a confirmation is signaled using the Confirm activity.
FaultHandler(s)	TryCatch	The try catch logic is more explicit now and you use the TryCatch activity to model your fault handling instead of using fault handlers on the composite activities.
IfElse	If	In WF 4, this can only have two branches, the If and the Else. For more branches, use the switch activity.
InvokeWebService	Send, SendAndReceiveReply	All web service communication in WF4 uses WCF.
Throw	Throw
TransactionScope	TransactionScopeActivity
WebServiceInput (output and fault)	Receive, ReceiveAndSendReply	WCF is THE messaging system to use with WF.
While	While/DoWhile	WF4 introduces the DoWhile in addition to the While to ensure the first iteration executes.

WF3 Activities with no direct WF4 equivalent

WF3 Activity	Note
ConditionedActivityGroup	Based on limited use (my guess) this activity was not moved to WF4.
Code	There is no code-behind file for workflows so there is no place to write code in the workflow. Create custom activities or use expressions where appropriate.
EventHandlingScope	No real equivalent, probably b/c this is an activity that gets overlooked or people use the state machine instead.
InvokeWorkflow	In the Beta, there is no activity like this one. One option is to host child workflows as WCF services and use the Send or SendAndReceiveReply messaging activities to start the child workflows.
Policy	In order to use rules in WF4, create a WF3 activity with a Policy activity inside it. Create properties on the activity and use them in the policy definition. Then use the InteropActivity to invoke the WF3 activity and execute the policy. You can use the properties on the activity as input and outputs to the policy.
Suspend	In WF4 there is more focus on having a “suspend on error” style exception handling, so direct suspend is not currently supported in the form of an activity.
SynchronizationScope	Again, my assumption here, this was not used a lot by folks so didn’t get moved over.
Terminate	No direct option to terminate, but exception handling has changed so that when a workflow throws an exception, you can abort, terminate or cancel it.
CompensatableTransactionScope	In WF4, use a Compensable activity and put a TransactionScopeActivity in the body.
State, StateInitialization, StateFinalization	There is no State Machine workflow in WF 4.

WF4 activities with no direct WF3 equivalent

AddToCollection<T>	Helper activity to simplify declarative workflow development and manipulation of collection variables.
Assign	Assigns a value to a variable – useful for declarative workflows.
CancellationScope	Allows you to define a scope of work and the steps to take if that work is canceled. Replaces the cancelation handler in WF3.
ClearCollection<T>
Confirm	Schedules the Confirmation logic for a Compensable activity.
ExistsInCollection<T>
Persist	Explicit declaration of persistence from the workflow. Replaces the need for the PersistOnClose attribute on activities.
RemoveFromCollection<T>
Switch<T>	Provides multiple branches of execution each based on a specific result from evaluating an expression.
Interop	Executes a WF3 activity in the context of a WF4 workflow. All public properties on the activity become In/Out arguments. Custom designers are not supported.

WF, WCF, Dublin Pre-conference from Dev Days

2009-06-22T15:44:26Z

I had a great time at Dev Days doing the pre-conference session on WF, WCF and Dublin. It’s always fun trying to present on beta technology, and there’s nothing like having the first demo crash Visual Studio to start the day. :) Thanks to all who attended, you can find the demos here.

Slides and demos from my WF 3 –> WF 4 talk at Dev Days

2009-05-29T14:44:24Z

Thanks to all who attended my talk on migrating from WF 3.x to WF 4 at Dev Days. I’ve posted my slides and demos which you can download for review. Thanks for a great show, and look for me to post some screencasts of several examples in the coming weeks.

Slides and demos from my custom activities in WF 4 talk at Dev Days

2009-05-29T14:41:31Z

For those of you who attended my talk at Dev Days 2009, I’ve posted the slides and my demo code for the custom activities talk. I’ve included the activities, the designers and the designer rehosting code along with some sample workflows using the activities.

Also, look for some screencasts that I’ll be doing showing these activities; it will be like watching the demos all over again.

Speaking at Microsoft Dev Days 09 in Hague, The Netherlands

2009-05-15T16:41:58Z

I’ll be speaking at Dev Days 09 in a couple of weeks. I’m excited to be doing a pre-conference day on WF and WCF 4 as well as “Dublin”. then I’ve got two WF sessions during the conference, one on building custom activities with WF 4 and another on moving from WF 3.x to WF 4.

After the show, I’ll try to get some screencasts up of a few of my demos, and you can check out our Pluralsight On Demand! where I’ll soon be publishing some modules on “Dublin”.

Issues with Live Mesh on Windows 7 RC

2009-05-15T16:06:52Z

I recently took the plunge and upgraded my 64 bit desktop from Vista to Windows 7 RC and for the most part I’ve been very happy with it. So far the only compatibility issues I’ve had were with some CD / DVD mounting tools and Live Mesh. I quickly realized how much I’ve come to rely on Live Mesh to keep files in synch between my desktop and laptop. All of my presentations and writing that I do live on both machines and I have a Tools folder with small utilities like .NET Reflector, Notepad2, etc. So when Live Mesh kept crashing under Windows 7, I got a little miffed.

I started by trying to set the compatibility to Vista or Vista Service Pack 1, but that didn’t fix the problem. I kept getting errors that the Mesh Operating Environment had stopped working and after closing it, it would restart, only to fail again in a few minutes. So, I did what any self-respecting developer does when they have a problem they can’t fix: I searched the web. Nothing, no love at all. I saw a few things about recent updates, which I’d installed already, and some registry hacks for the Win 7 beta, which were already incorporated into later builds of the product. So finally, I did the only logical thing, I uninstalled Live mesh, logged into Mesh.com and got the installer, and re-installed. A quick reboot, and all seems well. So, for those of you out searching the internet for a fix, hopefully this helps you out.

Of course, this is on My Machine, which is a home built x64 machine with an upgrade from Vista SP 1 to Win 7 RC. With all that in the mix, your mileage will likely vary. ;)

BizTalk Server 2009 Virtual Labs are now available

2009-05-13T22:18:00Z

Are you looking to try out BizTalk Server 2009 but don’t have the time to setup a full BizTalk environment? Then Microsoft’s Virtual labs might be right for you. The most popular labs for BizTalk Server have been updated for BizTalk Server 2009 and a few new ones focused on the features of BizTalk Server 2009. Check them out if you are interested.

In related news, I’m in the process of adding BizTalk Server 2009 content to the BizTalk Server Fundamentals course in Pluralsight On-Demand!. If you haven’t already subscribed, you should really check it out. I’m spending my free time these days learning about Agile Team Practices from David Starr and ASP.NET MVC from K. Scott Allen. It’s the next best thing to having these guys in a classroom with me. We’re continuing to expand the library too, so the subscription gets more valuable by the month – not many investments you can say that about today!

Screencast: Windows Workflow – Creating custom context channels for workflow services

2009-05-05T16:06:00Z

I’ve recently published a free screencast on how to create a custom context channel in workflow services.

.NET 3.5 supports managing context in a SOAP header or HTTP cookie, but that may not be where your context information lives. In this screencast I show an example of a custom channel that enables the context information to be passed in a URL to enable operation invocation from a link in an email.

Check out our growing collection of free .NET screencasts and videos. Subscribe to the Pluralsight feed to be notified when new screencasts are published. Also, check out our growing library of online .NET training courses -- see what you can learn with Pluralsight On-Demand!

Screencast: Windows Workflow – Managing conversations in workflow services

2009-05-05T16:04:00Z

I’ve recently published a free screencast on how to manage conversations in workflow services.

Conversations are special cases of context management in workflow services requiring extra information to correctly route messages. In this screencast, I show you when you need to think about conversations and how to properly write your workflows and clients to deal with them.

new cloudApp() developer competition

2009-05-05T14:56:25Z

Looking to show off your skills in building cloud applications using either .NET or PHP? Like to make a little $$ while you are at it. Well, if you bring your A game, you just might have a shot in the new developer competition that Microsoft is running. You can check out the details on the contest web site, and find links to all the tools you need to get started.

I’m looking forward to seeing some cool ideas come out of this and participating in the community judging.

From the website:

new CloudApp() is a US-based developer challenge for .NET & PHP developers creating cloud applications or services (hereafter "application") on the Azure™ Services Platform. Have your application judged by industry leaders Om Malik and Michael Cote and share your cloud coding skills with other developers. Grand Prize Winners will be announced on stage at Structure 09 and featured on azure.com.

Unfortunately, for those of you not in the US, you read that correctly, and this is only open to folks residing in the 50 states and DC. I’m sure it is for legal reasons, but that definitely limits the amount of cool submissions we’ll be seeing.

Screencast: Windows Workflow – Managing workflow services context in WF client applications

2009-05-01T16:19:00Z

I’ve recently published a free screencast on how to manage context information when using workflows, and the Send activity, to interact with workflow services.

When using workflows as clients to workflow services, the Send activity is used to manage context on the client. This screencast covers how to configure the send activity correctly with respect to context and how to manage the context manually.

Screencast: Windows Workflow - Managing workflow services context in .NET client applications

2009-05-01T16:16:00Z

I’ve recently published a free screencast on how to manage context information when using a .NET client to interact with workflow services.

This screencast shows how to manage context in .NET applications to enable multiple calls on the same proxy for different workflow instances, or to make calls to an existing workflow instance with a new proxy/channel.

NOTE: for reusing the same channel to make calls to different services, you should see this blog post that provides details on some extra steps required to turn off the automatic context management. If you fail to do this step, you will get the following exception message: “Context cached at the channel layer cannot be changed after the channel is opened.”

Screencast: Windows Workflow – Creating Custom Context Bindings

2009-05-01T05:12:00Z

I’ve recently published a free screencast on how to create custom context bindings in workflow services.

Microsoft ships several bindings that support context management, but they cannot possibly cover all of the scenarios you might need. In this screencast, I'll show you how to build your own custom context binding using a netNamedPipesContextBinding as an example.

Screencast: Windows Workflow Foundation workflow service context basics

2009-05-01T05:04:00Z

I’ve recently published a free screencast on the basic ideas around context management with workflow services.

This screencast walks through the basic ideas of managing context in workflow services and introduces several concepts that will be used for deeper exploration in other screencasts in the series.

Twitter or Syndication (RSS or ATOM)

2009-04-27T22:17:00Z

A friend of mine, Jon Helmberger, posted on this Facebook status the other day a great quote which really pointed out how some people use technology that is trendy, and not necessarily the most appropriate technology. “If RSS had a cooler name we wouldn't have shenanigans like this...” with the following link: http://tiny.cc/kxALC. In a nutshell, local Minnesota municipalities are posting information, of varying usefulness, on Twitter and Facebook.

I realize it must be hard for organizations that are not on the cutting edge of technology to make decisions about what to pick. For that matter, I have been talking to a lot of developers lately who have trouble keeping up with all the technologies, even from a single vendor like Microsoft. But it is frustrating to see people gravitate to the hot item and try to use it without really figuring out if it is the right technology for the job. I can’t imagine that with the 140 character limit in Twitter, an organization can convey much useful information. If the posts always end up linking to something else, how useful is that? It seems to me that having an RSS feed would be the more appropriate mechanism for conveying this type of information. There are so many tools for reading RSS / ATOM feeds and including them in a page, etc. Sure, a Twitter feed can be read as an RSS feed, but again, the micro format seems like an inappropriate means conveying anything other than the simplest bit of information.

We at Pluralsight have started using these technologies (Facebook and Twitter) to convey information about what is happening with classes, content, etc. Of course we are mostly on the cutting edge of technology and hopefully have some idea of the best way to use these technologies. However, even we are still learning how best to use these technologies and which information is best suited for each format.

What do you think, is Twitter an appropriate tool for this sort of thing? Do enough, or the right, people use it to make it worthwhile? Or are too many people caught up in the hype? What tools do you find work best for you to get information?