Philip Wolfe - Just the idea guy

WWF Persistence Demo

Wed, 18 Jun 2008 06:00:00 GMT

I was working through the WWF MSDN forums and saw some questions on the differences between states and statuses and how does persistence and idle work. I decided to get an example together that is illustrates these points without being overly complex. The result was this 1 workflow, 1 code file, and (the best part) self contained SQLExpress database.

The example shows how by changing the UnloadOnIdle setting in the config file, the developer can control how a workflow idles and unloads. It also demonstrates how delay activities help transition between states in a state machine workflow and how the timespans are min values, not exact. The delay activities rely on the load interval, another setting that can be controlled with a config file attribute. The final part is the database. This is a SQLExpress database that has all the necessary tables to run a persistence store and is right in the project! When the app runs, it connects to that database without the developer having to attach it to SQL Server. I have also uploaded the database as a seperate zip file to use in your other projects.

Enjoy.

Attachments:

TechEd Windows Workflow Foundation Presentation

Wed, 11 Jun 2008 06:00:00 GMT

Attached is the presentation I gave at TechEd this year. It was a heck of a lot of fun to prepare and give this talk on a technology I am very passionate about.

Session Description:
More WWF Hosting Options Than You Thought
Have you ever considered all the possible hosting environments for a Microsoft Windows Workflow? This session will explore different types of hosting, from simple to complex. (Including: simple scenarios such as Console hosted and Service hosted, intermediate scenarios such as Web hosted and asynchronous-Web service hosted, and complex scenarios such as synchronous-Web service hosted and WCF hosted). All of the demos show best practices for hosting in each scenario.

TechEd2008 SOA10-TLC.zip

A cool string formatting piece of code

Fri, 04 Jan 2008 07:00:00 GMT

Today I had to come up with a way to format phone numbers from a string containing just the digits. One solution was to just return a bunch of substring calls, but that didn't seem ".NET" enough so I poked around on the net a bit and found this idea.

http://www.thescripts.com/forum/thread361943.html

The post talks about a class that can format a string by using placeholders with substring parameters. Sounds cool, where's the code? I didn't find the code so I had to come up with it on my own. (See below.) I hope this helps you when you need to format strings.

using System;
using System.Collections.Generic;
using System.Text;

namespace Utilities
{
	/// <summary>
	/// This class returns substrings of an argument when used in a call to String.Format
	/// </summary>
	/// <remarks>
	/// Idea from (http://www.thescripts.com/forum/thread361943.html)
	/// It will use standard formatter placeholders to generate the string.
	/// The placeholders are in the form of {0:Sx,y}
	/// 0 = String.Format argument index
	/// x = Starting index of the argument
	/// y = Length desired
	/// </remarks>
	/// <example>
	/// To format 1234567890 into a phone number: String.Format(new StringFormatter(), "({0:S0,3} {0:S3,3}-{0:S6,4}", "1234567890");
	/// To format 14AB225 into an inventory location: String.Format(new StringFormatter(), "Item found in Warehouse {0:S0,2}, Room {0:S2,1}, Row {0:S3,1}, Shelf {0:S4,1}, Position {0:S5,2}", "14AB225");
	/// </example>
	public class StringFormatter : IFormatProvider, ICustomFormatter
	{
		///<summary>
		///Gets an object that provides formatting services for the specified type.
		///</summary>
		///
		///<returns>
		///The current instance, if formatType is the same type as the current instance; otherwise, null.
		///</returns>
		///
		///<param name="formatType">An object that specifies the type of format object to get. </param>
		public object GetFormat(Type formatType)
		{
			return new StringFormatter();
		}

		///<summary>
		///Converts the value of a specified object to an equivalent string representation using specified format and culture-specific formatting information.
		///</summary>
		///
		///<returns>
		///The string representation of the value of arg, formatted as specified by format and formatProvider.
		///</returns>
		///
		///<param name="arg">An object to format. </param>
		///<param name="format">A format string containing formatting specifications. </param>
		///<param name="formatProvider">An <see cref="T:System.IFormatProvider"></see> object that supplies format information about the current instance. </param>
		public string Format(string format, object arg, IFormatProvider formatProvider)
		{
			if (format.StartsWith("S"))
			{
				string[] parts = format.Remove(0, 1).Split(',');

				int start = int.Parse(parts[0]);
				int length = int.Parse(parts[1]);

				return ((String)arg).Substring(start, length);
			}

			return arg.ToString();
		}
	}
}

Useful data layer functions

Wed, 02 Jan 2008 21:00:00 GMT

A friend, Rob, and I wrote these functions today. You may find them helpful when coverting null values from stored procedures or datatables/datarows in your data layer.


/// <summary>
/// This method compares value with DBNull.Value and returns null or the value
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="value"></param>
/// <returns></returns>
public static T? GetValueTypeValue<T>(object value) where T : struct
{
	if (value == DBNull.Value)
		return null;
	else
		return (T)value;
}

/// <summary>
/// This method compares value with DBNull.Value and returns null or the value
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="value"></param>
/// <returns></returns>
public static T GetReferenceTypeValue<T>(object value) where T : class
{
	if (value == DBNull.Value)
		return null;
	else
		return (T)value;
}

VS 08 Gripes (Part 1)

Wed, 02 Jan 2008 07:00:00 GMT

I am using VS 08 full time now and I wish the VS team would leave well enough alone (or at least provide a way to change it back to the previous functionality).

This first one isn't functionality, it is more performance. Why does VS 08 lock up when adding items to the toolbox? It took 5 minutes to add 2 dozen controls from 10 or so assemblies from Telerik. VS 08 also locked up when I created a custom web control when it went to add it to the toolbox.
When working on web pages I like to switch between design and source. Now there is a button named Split where the source button should be. They should have moved split all the way to the right because I am in the habbit of clicking right next to design. (or at least let me customize the order because they screwed it up.) They also screwed up the order of the tool bar buttons for the solution window in VS 05 (if I haven't mentioned that yet.)
What kind of code is this? This is not what I want my developers following as an example. It appeared when I created a custom web control. Very ugly.

get 
{
 String s = (String)ViewState["Src"]; 
return ((s == null) ? String.Empty : s); 
}

Its in the Serialization Assembly!!

Fri, 31 Aug 2007 23:00:00 GMT

Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Runtime.Serialization.SerializationException: Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[SerializationException: Type 'System.Runtime.Serialization.ExtensionDataObject' in Assembly 'System.Runtime.Serialization, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.]
   System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type) +2271925
   System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context) +245
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo() +88
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +305
   System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.Serialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +50
   System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck) +438
   System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck) +131
   System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph) +12
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +2849

[ArgumentException: Error serializing value 'System.Runtime.Serialization.ExtensionDataObject' of type 'System.Runtime.Serialization.ExtensionDataObject.']
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +3056
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +1680

[ArgumentException: Error serializing value 'System.Object[]' of type 'System.Object[].']
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +3056
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +1680

[ArgumentException: Error serializing value 'System.Object[]' of type 'System.Object[].']
   System.Web.UI.ObjectStateFormatter.SerializeValue(SerializerBinaryWriter writer, Object value) +3056
   System.Web.UI.ObjectStateFormatter.Serialize(Stream outputStream, Object stateGraph) +126
   System.Web.UI.ObjectStateFormatter.Serialize(Object stateGraph) +52
   System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Serialize(Object state) +4
   System.Web.UI.Util.SerializeWithAssert(IStateFormatter formatter, Object stateGraph) +37
   System.Web.UI.HiddenFieldPageStatePersister.Save() +106
   System.Web.UI.Page.SavePageStateToPersistenceMedium(Object state) +82
   System.Web.UI.Page.SaveAllState() +552
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1676

Version Information: Microsoft .NET Framework Version:2.0.50727.832; ASP.NET Version:2.0.50727.832

A really nasty error

Sat, 11 Aug 2007 00:00:00 GMT

I have to write about a really nasty error I was getting last week. I couldn't find much online about it. Most of the information was related to ASP.NET but mine was related to Visual Studio .NET 2005. This occured after I installed a version of Infragistics NetAdvantage. I don't blame it on that but it is a wierd coincidence. The error was:

Cannot execute a program. The command being executed was "C:\Windows\Microsoft.NET\Framework\v2.0.50727\csc.exe" /noconfig /fullpaths @"C:\Documents and Settings\username\Local Settings\Temp\xxxxxxxx.cmdline

It would occur when VS.NET would start and try to load Resharper. It would also occur when VS.NET would try to build a Windows Workflow Foundation project with no class files in it. It would ALSO occur when I would try to connect to Team Foundation Server. It would give me an error of tf31001 and say that the server had returned that error, when everyone else was working just fine.

It turns out through some logging that it was a problem whenever the code tried to use the XMLSerializer and create a temporary folder or files in my temp directory. I removed everything related to .NET development (except the framework), reinstalled everything, and the problem was still there. I finally found enough blogs talking about permissions so I did a repair on the .NET 2.0 and 3.0 frameworks. Bingo, it was fixed. I hope this helps those of you facing this error (and those of you who ran the IIS lockdown tool :-) )