August 2006 - Mike Taulty's Blog

More P2P stuff seems to be going out on Noah Horton's blog . I'm reasonably excited about the whole P2P platform these guys are building and I think that it has the possibility to have a very big impact on applications and users over time. You can just picture the scenarios for chat, voice, video, gaming, etc. that this stuff enables.

Using the code from the previous post , if I go ahead and drag a new Activity to the design surface and then try and do something simple like renaming it from its automatically generated name (there's a service doing that somewhere I'm sure) then I get an error saying "You need to provide an ITypeProvider " so that looks like a sensible thing to try and improve. I got bogged down a lot about ITypeProvider because the original sample uses an instance of the TypeProvider class that's already there in the framework but I was reading this post from Jon Flanders which seemed to suggest that you had to write a custom ITypeProvider to get things to work but that hasn't seemed to be the case for me (so far - I'm sure it'll come back to bite me). ITypeProvider is just a service that the various pieces of componentry that we're plugging together here can use to resolve Types that they don't know about. So, I created an instance of ITypeProvider and added it to my IDesignerHost as a service; private void InitialiseTypeProvider...

Interesting and new to me. Windows Live has a Contacts gadget for sharing some information (I haven't yet read how much and what the level of control might be) about your personal contacts with websites. There's an example here: http://dev.live.com/mashups/partystart/ which mashes-up (oh yes, I'm learning the lingo) Virtual Earth with Live Contacts to show you where your contacts are. I tried this with some of my contacts and all of them said "Sorry, the contact doesn't have any address information" so there could be a slight flaw in this in that I'm guessing a lot of people are like me in that they've submitted the very bare minimum of information about themselves to Live at the time of registration. Update: Must admit that I thought about this quite a bit yesterday after making this post and what it seems to facilitate seems a bit scary to me. If I understand it right then if Alice has Bob in her contacts list and Bob's contacts details include things like his home address then Alice can send Bob's home address...

Following on from this previous post a tip that I'd pass on about hosting the designer. I've been finding it a bit confusing to work out which services I need to add in order to affect which functionality. One of the ways in which I've tried to work this out is by doing my usual trick of using the; Debug->Exceptions->CLR Exceptions dialog box in Visual Studio so that when any sample I'm running throws an exception I can see what those exceptions are even if they are ultimately caught by the application. With the Workflow Designer hosting this has been quite useful in letting me see that certain services are missing from the configuration.

I've been shying away from this. I've heard from a few people that hosting the designer componentry that Windows Workflow Foundation provides is quite tricky and so I've generally been focusing on runtime bits and pieces and keeping my head down and hoping that I'd not get spotted hiding in the corner but you can only hide for so long :-) I've been pouring over the designer hosting for only a few hours and the initial conclusion I've come to is that the designer hosting isn't hard per-se but; The designer can do a lot of things for you. It can do the following and probably a whole bunch more; Display a Workflow Perform commands (copy/paste/zoom/etc) on the items in the Workflow Work to generate properties and fields in classes as the user designs the Workflow Work to generate event handlers in classes as the user designs the Workflow Declaratively bind activity properties to each other Declaratively define rules Work to load/persist workflows/code and rules Provide interaction with the toolbox for dragging-dropping...

One of the technologies that seems to be raising its profile in Windows Vista is Peer 2 Peer. There are a bunch of Peer to Peer API's that were (as far as I'm aware) first made available as an add-on to Windows XP Service Pack 1 but are present in Sp2 and Vista out of the box. The SDK documentation is online but, frankly, there really don't seem to be any good, plain-English write-ups around exactly what these API's (and their higher-order collaboration friends) can do for you. I think there's also a barrier to entry because of; The P2P stuff is wedded into IPV6 and I guess most people haven't cracked that yet (I certainly haven't). It gets more complex when you read about tunnelling IPV6 over IPV4. The API's are not the easiest thing in the world to call from managed code. About the best material that I can find out there on the web is written by Adrian Moore and he's written a bunch of articles for The Code Project that talk a bit around the "nuts and bolts" of getting some of this stuff to work but, for me...

Saw both of these films on DVD at the weekend and thought that they were great (this is just me making sure that I can post images) with Live Writer .

I'd missed this change to the July WCF; http://blogs.msdn.com/mahjayar/archive/2006/07/08/660176.aspx (probably because I'm not really using it as of yet and have been confined to Beta 2 for a while).