December, 2010

This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: Introducing Razor (July 2nd) New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (Dec 15th) Implicit and Explicit code nuggets with Razor (Dec 16th) Layouts and Sections with Razor (Today) In today’s post I’m going to go into more details about how Layout pages work with Razor.  In particular, I’m going...

Implementation Using FlowDecision & FlowSwitch Within a FlowChart, the FlowDecision and FlowSwitch activities can each be used to implement the Simple Merge Pattern. FlowDecision The FlowDecision enables a binary Exclusive choice between to branches by having an output branch for...

This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (today) In today’s post I’m going to discuss two useful syntactical features of the new Razor view-engine – the @: and <text> syntax support. Fluid Coding with Razor ASP.NET MVC 3 ships with a new view-engine option called “Razor” (in addition to the...

Recently I saw a message on the WF4 Forum where someone was asking for help learning how to consume a WCF service from a Workflow. In this post I’m going to walk through how you can consume a WCF service from a Workflow where both the service and the workflow live in the same web site. This should be simple, but unfortunately it is not as simple as it should be. Create an ASP.NET Web Application Start Visual Studio 2010 and Create a new ASP.NET Web Application Add a new WCF Service to the project...

This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (Dec 15th) Implicit and Explicit code nuggets with Razor (today) In today’s post I’m going to discuss how Razor enables you to both implicitly and explicitly define code nuggets within your view templates, and walkthrough some code examples of each of them...

Auto-start is a really cool feature of Windows Server AppFabric. Recently I was asked about how you can do some kind of process initialization in your code with Auto-start (which the documentation implies that you can do). This led to a discussion with a number of questions that we want to address What does Auto-start really do? How much faster is the first call to my service if I use Auto-start? How can I write code that is called when the service is auto-started? endpoint.tv - WCF and AppFabric...

Implementation using Parallel & ParallelForEach The Parallel and ParallelForEach activities can be used to implement the Simple Merge Pattern by configuring the Completion Condition such that it evaluates to True whenever the first child branch completes. Parallel The following example...

I’m happy to announce that we have just posted a “Labs” release on our http://wf.codeplex.com site with some new Caching Activities . These activities work with Windows Server AppFabric Caching making it possible for you to use the cache directly from your workflow In this example I’m implementing the “Cache Aside” pattern where I first try to get the value from the cache and then if I can’t find it I get the value from a repository of some kind and then...

On Thanksgiving day while I was running in the snow I had an idea – what if you could create an Operation Behavior that would allow WCF to cache the result of a service call in Windows Server AppFabric Cache ? Download WCF AppFabric Caching Caching Sample Behavior So I created a sample application that does this by implementing an attribute that implements IOperationBehavior and IOperationInvoker along with a Service Behavior that supports AppFabric Caching.  I wanted to make this work with...

If you're interested in the problem space of building hybrid solutions that leverage both Azure AppFabric and Windows Server AppFabric, go check out this really awesome blog entry I was honored to help author: Hybrid Cloud Solutions With Windows Azure...

Simple Merge Pattern The Simple Merge Pattern represents the case where two or more branches come together to execute a single, shared branch of common logic following independent branches. The key to the simple merge is the lack of synchronization...

Implementation Using State Machine The State Machine's Transitions define a very natural way to implement the Simple Merge Pattern, because multiple states can transition back into a single state. The figure below shows the payment processing scenario, which evaluates the...

A little over a month ago we launched our new WCF Web Apis on Codeplex . Since then a bunch of folks in the community (and some internal folks) have been posting about their own explorations / thoughts of the new bits. it’s great to see the work that they are doing! I am going to start aggregating these and periodically (I am not committing to a cadence but am aiming for monthly) post pointers to whatever I find. Appreciate any suggestions to the format. Blogs On WCF Web Apis Microsoft WCF gets serious...

If you're interested in building a custom, stand-alone application for designing Workflows and Workflow Services with .NET 4.0, you should check out the reference application we built that is now available from the MSDN Code Gallery. It's a feature rich...

Just posted a new release of Microsoft.Activities.UnitTesting This release incorporates the Task Parallel Library to greatly simplify test code. Episodes You can now create a task that will run an episode of work in the workflow. An episode is simply a pulse of work that the workflow runs. For example an episode might look like the following Thread Action host Run the workflow host Wait for idle Workflow Activity 1 Workflow Activity 2 (creates a bookmark) Workflow Invoke Idle delegate - host sets...

In playing around with the possible solutions or improvements to [previous post:] the heaviness of finalizable WeakReference objects, an obvious thing to do was replace WeakReference objects with using GCHandle structs. Here’s a test program which adds many WeakReferences to a HashSet. (Note, HashSet uses arrays as the underlying storage.) The WeakReferences will point at some temporary objects which soon become collectable. The results are that in a minute or two we can create up to about 12 million...

Briefly diverging from regular posts: here’s something really fun. As far as I know, prior to 4.0, .Net has had, two built in ways to do weak object references. 1) WeakHandle 2) GCHandle, which is what WeakHandle uses under the covers. If you have ever tried to use WeakHandle in a collection, e.g. attempt to maintain a ‘weak set’ or a ‘weak list’ as you might want in a weak event notification scheme, and then tried to stress test your solution for scalability, you find some slightly interesting problems...