Assorted Windows Workflow Foundation & Live Mesh : XAML Activation

Project template for XAML Activation Console Application

tomlake — Fri, 19 May 2006 00:05:00 GMT

If you work with XAML activation from time to time and like being able to debug your workflow using a console application you should install these templates. However, you don’t like having to modify the default console application template each time. I created sequential and state machine console application project templates for both Visual Basic and C#.

This posting is provided "AS IS" with no warranties, and confers no rights.

Examples of using Persistence and Tracking in ASP.NET

tomlake — Wed, 17 May 2006 21:12:00 GMT

When you are working with ASP.NET you may have the need to persistence and / or tracking. I have put together two examples, one with shared databases and the other with separate, and included the command scripts to create the databases for you. There are VB and C# versions of each sample.

When you run the project you will start on Default.aspx. If there are no existing orders that have not been completed you are redirected to Order.aspx. If there are any existing orders there will be a link for each existing order. Click on the link to start processing the order from its current state. The order number will be retrieved from the tracking database for any order that is at least in the Created state. You can click on the enabled button to transition the order through the order process.

This posting is provided "AS IS" with no warranties, and confers no rights.

Using XAML activation in ASP.NET with a StateMachineWorkflow

tomlake — Mon, 08 May 2006 21:03:00 GMT

If you want to use XAML activation in ASP.NET you will need to be using Windows Workflow Foundation Beta 2.2, that can be found here. The reason for this is that although XAML activation works in most cases with Beta 2 it isn’t officially supported in that build because it was added as a feature at the last minute and was not fully test yet.

Below is a sample that uses XAML activation to start a StateMachineWorkflow in ASP.NET.

This posting is provided "AS IS" with no warranties, and confers no rights.

XAML activation and how to use it

tomlake — Wed, 03 May 2006 02:41:00 GMT

XAML activation is when you use the serialized xoml file to create and run a workflow instance. You will use one of the following WorkflowRuntime methods to create the workflow instance:

public WorkflowInstance CreateWorkflow(XmlReader workflowDefinitionReader);

public WorkflowInstance CreateWorkflow(XmlReader workflowDefinitionReader, XmlReader rulesReader, Dictionary<string, object> namedArgumentValues);

public WorkflowInstance CreateWorkflow(XmlReader workflowDefinitionReader, XmlReader rulesReader, Dictionary<string, object> namedArgumentValues, Guid instanceId);

Activation can be used for sequential or statemachine workflow, samples for each are attached to this post. You are not able to use any code beside. This will require you to add any needed variables or handlers to a compiled type, like your base activity.

The only difference between a xoml file used with activation and one that is compiled into a type is the x:Class attribute. The attribute is used by the workflow author to explicitly state that the workflow must be compiled into a type and to define the class name for that type.

If you are getting an exception when the call to CreateWorkflow is made try the following to help resolve the error(s):

try

{

WorkflowInstance instance = workflowRuntime.CreateWorkflow(xomlReader, ruleReader, parameters);

instance.Start();

waitHandle.WaitOne();

}

catch (WorkflowValidationFailedException exp)

{

StringBuilder errors = new StringBuilder();

foreach (ValidationError error in exp.Errors)

{

errors.AppendLine(error.ToString());

}

MessageBox.Show(errors.ToString(), "Workflow Validation Errors");

}

To bind to an event or condition handler in the base workflow you will need to manually update the xoml file since you can’t use the designer to do this. The syntax to use is the following:

EventOrConditionName="{ActivityBind NameOfWorkflowInstance,Path=EventOrConditionHandler}"

This posting is provided "AS IS" with no warranties, and confers no rights.