Experiential development

Ajax Data Context - 4.0

2009-11-18T22:34:00.004+02:00

Intro:
I was at Tech-Ed South Africa this year (2009) and I saw a very impressive demo by mmmmh, I think it was John Carter from http://lostintangent.com

He was doing an introduction to Ajax 4.0 in particular the new Data Context. Well I must say I was quite impressed, I don’t know about you but I really don’t like the current MS Ajax implementation. The update panel which has been widely adopted as the Ajax control of choice by many .net developers, although it is easy to use it comes with a very high bandwidth cost.

After Tech-Ed I had a look around and tried to find a nice sample of the demonstration that Jon gave but alas there was nothing to be discovered. So after about four hours of searching I did what any respectable developer would do, that’s right I grabbed all the little bits and pieces of that that I could lay my grubby little fingers on and started building my own.

Some background info?
DataContext is an object that is capable of consuming a server-side resource that serves JSON or XML data. It will then store it on the client site and you can bind it to sys-template, manipulate it and commit the updated data (just the updated data). If you want real details on it click here

Demo project?
To show you how much better the new 4.0 Ajax implementation is project will use normal html file and not aspx files.

The project has three JavaScript files MicrosoftAjax.debug.js, MicrosoftAjaxAdoNet.debug.js, and MicrosoftAjaxTemplates.debug.js file these are the Ajax libraries and it uses the .net Entity framework to create the service layer and two htm sample files, they use different methods

The js file are all .debug files this is to allow intelisense for JavaScript, you will see that that they have /// xml comments.

Download and unzip the sample code If you don’t have NorthWind database the restore the backup that I have included in the App_Data folder. Make sure that the web.config is set up correctly and check the NorthwindEntities connectionString If you have problems you might want to recreate the manWindDataService layer again and that should be about it.

Download:
Click here to download the sample project.

References:
http://lostintangent.com
http://msdn.microsoft.com/en-us/magazine/cc163413.aspx

Possible problems & resolutions
If you cannot browse to the manWindDataService.svc file and you are getting a 404.3 error.

Description: The page you are requesting cannot be served because of the Multipurpose Internet Mail Extensions (MIME) map policy that is configured on the Web server. The page you requested has a file name extension that is not recognized, and therefore is not allowed.

Error Code: 0x80070032

Notification: ExecuteRequestHandler

Locate “servicemodelreg.exe” it should be in the “Windows Communication Foundation” folder. Once you have located open cmd and run “cd C:\Windows\Microsoft.NET\Framework\v3.0\Windows Communication Foundation“ and then servicemodelreg –i

Then you might get another error, “The application domain or application pool is currently running version 4.0 or later of the .NET Framework. This can occur if IIS settings have been set to 4.0 or later for this Web application, or if you are using version 4.0 or later of the ASP.NET Web Development Server. The element in the Web.config file for this Web application does not contain the required 'targetFrameworkMoniker' attribute for this version of the .NET Framework (for example, ''). Update the Web.config file with this attribute, or configure the Web application to use a different version of the .NET Framework.”

This is because the IIS App Pool is now running under .net 4.0.

1. Open IIS 7.0 Manager
2. Open “Basic settings” and find Application Pool Name
3. Open Application Pools
4. You can see that after installing .NET framework 4.0 all Application pools are updated to run under .NET Framework v4.0
5. Find application pool from step 2, click Basic (or Advanced) Settings from the right panel.
6. AND FINALY change it to “.NET Framework v2.0.50727” click “OK”
7. THAT’S IT !!!

SnapDNS – DNS Library for Microsoft DNS servers

2009-07-01T21:10:00.003+02:00

Intro:
This isn’t so much an article as it is a free DNS management library and a demo project.

This Library makes updates to Microsoft DNS servers possible from .NET applications. The library supports the following record types: A, CNAME, MX, TXT, NS. ASP.NET DNS Manager

Some Details:
Included in the project is the snapDNS.dll this is the heart of the project it uses the System.Managment namespace to create DNS records in a Microsoft DNS server using WMI. Take note of the WMI configuration below it is probably the most crucial part to getting this working.

DEMO SETUP
Unzip the folder to the wwwroot folder and setup and web application version ASP.NET 1.14

WMI Config
Microsoft DNS Server 2000/2003, WMI Configured to allow ASP.NET user access.
http://msdn2.microsoft.com/en-us/library/aa384642.aspx this is to be done on either the same machine as the website or a separate server. I would recommend that for test purposes you put them on the same machine to avoid permission issues.

WMI Setup:

Click Computer Management
Click Services & Applications
Right Click WMI Control and go to properties
Click on the Security Tab
Expand the Root node.
Select MicrosoftDNS then click Security button.
Add the appropriate users. ASP.NET

Demo:
The demo version is unlimited. Please note that this is still a work in progress. If it attracts interest I will consider more development.

Download Demo.

WCF File Transfer: Streaming & Chunking Channel Hosted In IIS

2009-01-15T22:48:00.009+02:00

Intro:
This article describes how to implement WCF File Transfer methods hosted in IIS. This includes two techniques Streaming and Chunking Channel.

We needed a scalable file upload facility and after much research found the two best methods Streaming and Chunking Channel for reasoning see the references below. After spending many days and night scouring forums and samples I finally managed to get Streaming and Chunking Channel file transfer services hosted in IIS.

Streaming:
I used the Streamed Upload from Pablo M. Cibraro article Sending Attachments with WCF. I then added two new projects to the solution w3service and w3client.

w3service is a WCF service library project that I then add a simple echo function and a upload function the implements a [OperationContract(IsOneWay=true)] and a [MessageContract()] that allows for a message header and body.

I then added the service.svc file that points to the w3Service.Service methods and a web.config file with my basicHttpBinding. You will need to change the in the web.config and the filepath variable in the Service.cs file. Then build the w3Service project and deploy it to your IIS server. Whatever you do make sure that you give the IIS virtual directory sufficent permission to save the file.

Now that we have the WCF service hosted in IIS you can navigate to it http://localhost/ServiceName/service.svc?wsdl and make sure that it loads. We now need to consume the new service hosted in IIS.

WE then use the w3client console application to consume the w3service. Run “svcutil.exe http://localhost/ServiceName/service.svc?wsdl /mc” in the visual studio command prompt and then include the output.config content in the app.config file and import the serive.cs file into the application. Check the app.config file and make sure that the transferMode is set to StreamedRequest and that your endpoint matches. Also make sure the maxReceivedMessageSize is increased.

Make sure that you use the /mc in the svcutil.exe tool, otherwise it will not generate the proxy as you would expect.

That should be that. Run the w3client application and test you file transfer. Hopefully all works out for you.

Chunking Channel:
For this I used the Chunking sample from LarsW.ChunkingChannelEx-0.9. I first customized it to use the same [MessageContract()] functionality that the Streaming sample uses. After that I followed the same steps as above in setting up the w3service and w3client projects with a few distinct differences. With the major differences being in the .config files.

For the w3service config you will need to use bindingExtensions to configure the httpChunkingBinding. You will also need to change the to point to your IIS server. Once you have the WCF service hosted in IIS you can navigate to it http://localhost/ServiceName/service.svc?wsdl and make sure that it loads.

We now need to consume the new service by using the “svcutil.exe http://localhost/ServiceName/service.svc?wsdl /mc” tool and copy the generated proxy to your w3client application. Make sure that you use the /mc in the svcutil.exe tool, otherwise it will not generate the proxy as you would expect. For Chunking we will also have to make sure that the contract is in the client application. This is done because of the ChannelFactory implementation and configuration.

Conclusion:
After initial testing you can use Fiddler to examine the difference in the way the two samples work. You can also configure both solutions to use SSL.

Code:
Like a picture paints a thousand word so code can make things seem o so clear. Included in my samples are the modified solutions that are mentioned above that I derived my prototypes from.

Download Streamed Sample
Download Chunking Channel Sample

Chunking Channel https
Streamed https

References:
http://msdn.microsoft.com/en-us/library/aa717050.aspx
http://code.msdn.microsoft.com/WCFResources/Release/ProjectReleases.aspx?ReleaseId=1534
http://code.msdn.microsoft.com/WCFResources/Release/ProjectReleases.aspx?ReleaseId=1546
http://kjellsj.blogspot.com/2007/02/wcf-streaming-upload-files-over-http.html
http://weblogs.asp.net/cibrax/archive/2007/08/29/sending-attachments-with-wcf.aspx

In the beginning

2009-01-09T14:53:00.000+02:00

Ok, this is just a test post to make sure that everything is looking juicy which I'm sure it is. For my first real post I will be posting a WCF file transfer sulution that I recently worked on in which I have two samples of large file transfers with Streaming and Chunking Channel both configured to be hosted in IIS.