April, 2010

It’s funny how you walk around with a question on your mind for a couple weeks and then one day it just suddenly feels like the ‘right time’ to go look for the answer. Question: Does VS 2010 allow you to extend the (nice) integrated unit testing to run tests in custom ways? Answer: Yes! Actually it was easy to find a guide with a sample [RunAsUnitTest] extension on the VS Team Test blog. [RunAs = ‘‘run as user’)] The scheme is: define your own custom [TestClass] attribute, and VS will load tests...

We talked about WF4 Activity overview and WF parameters in particular in previous posts. In this installment, I'm going to focus on WF variables. Variable Variables are modeled by Variable class. namespace System.Activities { public abstract class Variable : LocationReference { public ActivityWithResult Default { get ; set ; } public string Name { get ; set ; } … public object Get( ActivityContext context); public void Set( ActivityContext context, object value); } } public sealed class Variable...

[Rewrite - 06/04/10] Here’s a little MEF sample (minus definition of TestMetadataFilteringCatalog) that I wrote, (not intending it to be a sample): Its operation confused the heck out of me. I couldn’t understand why both FooTest and BarTest were being populated in p.Actions. Because function Filter() should only match exports with metadata: Category == Category.Y. I started looking at MEF because we are thinking of using the composition scheme in a new project. While reading more about it, I came...

The WF State Machine Activity Pack CTP1 is released on CodePlex NOW!! Please check it out. Last year in PDC2009, I ran a chalk talk on our work on WF 4 State Machine Activities and promised the team would ship an implementation for public review after the release of Visual Studio 2010 . Today, I am so excited to let you know that we have delivered it on CodePlex as planned. This CTP contains a state machine runtime and a graphical state machine designer implementation, and they are optimized to handle...

We are happy to announce that we have released the WF ADO.NET Activity Pack CTP1 on CodePlex . The WF ADO.NET Activity Pack CTP1 contains a set of WF 4 Activities based on .NET Framework Data Providers . These activities enable accessing a database through SQL commands or stored procedures within a workflow. You can drag-and-drop the ADO.NET Activities to your designer surface and access the database just like what you can do with ADO.NET. It is a very simple way for you to integrate business data...

By this time you are saying, I don't want tips/trouble shooting anymore. I have a large workflow and I cant really re-factor it further. How can I improve the performance? One of the customers actually told us that the way his system was designed, re-factoring might result into affecting runtime performance since he would need to be passing context across different State Machines. Hence, he would rather take the design time performance hit, than the runtime performance issues. Well, we have heard...

Recently, we worked with one of the customers whose designer launch was painfully slow. The project was a medium sized one and hence the performance degradation was particularly baffling. To figure out what's wrong, I did an Attach to Process(to debug) with another VS instance to the VS with the workflow designer and turned on all the exceptions. Next, I tried to launch the workflow designer and Whoa… I am getting hundreds of File IO Not Found Exceptions. No wonder the performance was slow. I...

In the 1st segment , I talked about high level principle for WF4’s data model design. I’m going to talk about WF Argument in particular in this post. Argument We’ve briefly touched this before: in WF4, arguments are modeled by Argument class. namespace System.Activities { public abstract class Argument { public Type ArgumentType { get ; internal set ; } public ArgumentDirection Direction { get ; internal set ; } public ActivityWithResult Expression { get ; set ; } … public object Get( ActivityContext...

Before, we start talking about the WF3 design time performance, let me clarify some of the terminologies: 1. WF3 is the version of Workflow shipped as part of .NET Framework 3.0 and 3.5. Note that WF3 is also shipped as part of .NET Framework 4.0. Meaning, System.Workflow.* assemblies are shipped as part of the latest version of the framework. 2. WF4 is the latest version of Workflows we are shipping first time as part of .NET Framework 4.0. Meaning, System.Activities.* assemblies are shipped for...

In previous blogs , we went through how define an Activity’s execution logic. But this is not enough. To build any meaningful Activity, developers also need to the activity’s state and data flow. In this post, I’m going to talk about WF4’s Activity data model. Argument and Variable 101 WF is just another higher level programming language that share a lot of similarity with popular imperative procedural programming languages. So let’s first take a look at data model of a typical procedural language...

The MSDN documentation on the WF designer shell has a very short section describing how WF designer fonts and colors work. Here is a bit more detail. You can manually change the colors and fonts used by the WF designer using the Tools->Options dialog box. The Workflow Designer for WF 4.0 does not have its own color scheme/font scheme context. Instead, it uses the environment fonts and colors. To change the color scheme: Go to Tools->Options to launch the dialog Under the Environment node, select...