29 בספטמבר 2009
I am playing with WF 4.0. I accidently pressed "Reset Toolbox" in a WF 4.0 project. This broke the toolbox. All the Flow chart and messaging activities were gone and I could not add them back manually. Only the procedural tab activities remained.When I tried to add the missing activities manually (choose Items) I could not find them under the activities tab. To solve this issue simply delete the .tbd files under: XP: %USERPROFILE%\Local Settings\Application Data\Microsoft\VisualStudio\10.0 Vista: %USERPROFILE%\AppData\Local\Microsoft\VisualStudio\10.0 Enjoy
24 בספטמבר 2009
WF 4.0 is a revolution in relation to WF 3.5. I want to speak about a new mechanism called conformation. In WF 4.0 every CompensableActivity has three handlers: Cancellation handler Compensation handler Confirmation handler The idea of Cancellation and Compensation is the same as it was in WF 3.5. If the activity is still active (executing state) and an exception occurred or an activity on an upper level completes (the activity that contains the CompensableActivity) than the activity would cancel and the cancelation...
23 בספטמבר 2009
MEF – Managed extensibility framework is one of the most exciting new technologies brought by the new .Net framework 4.0.
Using MEF it is simple to create extensible applications.
There are so many extensibility design patterns but non is as simple as MEF.
One of the most popular extensibility pattern is the “provider” pattern. You define an interface that a provider should implement and in config you specify the location of the actual provider. On startup someone has to read the config, load the assembly, create an instance of the provider and start to work.
There are two main problems.
1. The configuration...
22 בספטמבר 2009
In one of my last posts I spoke about pub-sub using WS discovery. Now I want to speak about the implementation of pub-sub using .Net Services. .Net services is a future infrastructure running on the cloud that will provide ISB (Internet service bus) capabilities. The .Net services includes an access control infra, an orchestration infra, an addressing infra and finally a messaging infrastructure. I will go deeper on each of those on future posts. The messaging infra comes in the form of WCF bindings so for anyone who uses WCF it is very easy to learn and...
13 בספטמבר 2009
AJAX is the new Hot technology concerning web application. It allows the client to do much more than it used to and to achieve a much better user experience.
AJAX is based on XmlHttpRequests that the browser creates while the page is presented on the browser. The client does not know that under the cover so many requests are being sent. Ajax is a java script technology running mostly on the client side and on the server the following question arises: will the average AJAX-enabled web-application be able to tell the difference between a real and a faked XmlHttpRequest?
9 בספטמבר 2009
I have implemented many pub sub infrastructures for many customers. I found out that one of the major rezones they used the pub sub infra was to be able to tell that a service just went up. Now with WCF 4.0 all this pub sub infrastructure we built is not needed any more. A service can use WS Discovery messages and publish the fact that it is up. Simple and clean! The question is what about other events? Well you can always keep using the pub-sub infra but I am looking for...