March 2005 - Mike Taulty's Blog

In my previous posts about Indigo messaging making use of channels; A slightly different "hello world" for Indigo Layers of Indigo Indigo- Moving on from IInputChannel to IRequestChannel I went with the default encoding of the messages that were sent on the wire whilst in this posting Layers of Indigo I mentioned that it's possible to plug in an encoder (a class deriving from MessageEncoder with primary methods looking to be ReadMessage, WriteMessage ) in order to change the nature of the message on the wire. One way in which we can alter the encoder is to switch the MessageEncoderFactory property on the HttpListenerFactory / HttpChannelFactory before beginning to make use of it. The 3 supplied variants of MessageEncoderFactory look to be BinaryMessageEncoderFactory, TextMessageEncoderFactory, MtomMessageEncoderFactory . The "client" side code of my sample now looks like this if I switch in the BinaryMessageEncoderFactory; static void Main(string[] args) { HttpChannelFactory factory = new HttpChannelFactory...

In trying to understand the Indigo CTP, the sketch that's resonating best with me right now is the one below which I've stolen from a slide-deck and shows how the technology is layered . An application can make use of any or a mixture of the layers. At the bottom, there's a messaging layer. This is what I've been playing with a tiny bit so far. The messaging layer moves messages from A to B and it does so by providing an abstraction called a channel which flows from A to B over a transport (possibly in one or more channel-specific directions - one-way, both-way, request-reply etc). Built-in transports include HTTP, UDP, TCP and an IPC transport. Channels feel very much like sockets to me in that you create a channel that points to a particular address and you accept incoming channels providing communication back to a caller. Channels transmit messages which are themselves a modelling of a SOAP envelope (in their header/body structure). When sending a message down a channel the message is put through an encoder...

Windows Server 2003 Service Pack 1 released yesterday. There's a press-release here http://www.microsoft.com/presspass/press/2005/mar05/03-30winservsp1pr.asp that you can follow. Hidden down at the bottom of that is a mention of the fact that the versions of Server 2003 for the x64 platform and the version of Windows XP Professional for x64 have both gone out of the door as well which has to be good news for those of us with a 64-bit machine :-)

There's something that the Indigo team seem to be doing with their proxies and generic types that I hadn't really thought about previously. The pattern looks something like this; class b<T> { public b() { } protected T _member = default(T); } interface IDo { void Do(); } class d : b<IDo>, IDo { public d() { } public void Do() { _member.Do(); } } I stared at this for quite a while as I hadn't seen this yet in .NET generics (it feels a little more like templates in C++ to me) and I was wondering for a while how this worked until I realised that the class d in my example there isn't actually a generic type at all. So, you could not call Do() in the class b without some kind of constraint which would kill the whole idea but you can call it in d because d is not a generic type at all. I'm not quite sure what you call it but it's an interesting thing to see :-)

In ASP.NET 2.0 we have the provider model where storage for the different API sets (e.g. Membership, Profile, Navigation, etc.) is pluggable in that you write a provider for your particular store if we don't ship one that you want to use. I got asked for a sample provider the other day and struggled to find one on the web so I'm including a link here to the online VS 2005 docs which have a sample membership provider for ASP.NET 2.0 The link's here; http://winfx.msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_aspnetcon/html/d8658b8e-c962-4f64-95e1-4acce35e4582.asp

A new set of "Web Services" MSDN Nuggets have started to drop out on the UK MSDN Site . MSDN Nuggets are 10-15 minute demonstration clips of how to get stuff done with the .NET Framework each one exploring a particular topic with little/no presentation and a lot of code/demo. Here's the link http://www.microsoft.com/uk/msdn/events/nuggets.aspx , the topic sections are now; .NET Nuggets (i.e. VS .NET 2003 and .NET 1.1) SQL Nuggets (i.e. SQL Server 2005) Web Services Nuggets (i.e. ASMX in .NET 1.1 plus Web Services Enhancements V2.0) There's more to come :-)

There's an important post over here Keep Writing SharePoint Web Parts Until (at least) 2006 about the interoperability that you can expect to get between Whidbey ASP.NET 2.0 WebParts and Windows SharePoint Services WebParts.

I got some feedback from Oliver Sturm that my blog site displayed horribly in FireFox so I grabbed myself a copy tonight and took a look and he's definitely right (thanks for sending me the pictures, Oliver). So...the blog site has a new theme (the .Text "blue" theme) which seems to display a whole lot better in FireFox and IE. (No way I want to divide my already limited readership!)