Let's consider the example:

• Fresh installation of Windows 2008 with Web Server role IIS and ASP.NET installed.
• A web application using AjaxToolkit

By default the Application Pool on IIS 7 is set to Integrated Pipeline, which does not work with AjaxToolkit and switching to Classic mode caused several issues:

1. 404.17 - File Not Found
   Take a look on the 'handler' in the 'Detailed Error Information' - IIS treats .aspx file as a static content means ASP.NET is not installed on IIS with your application, and, definitely you need to register it for your site, but ..
   
2. aspnet_regiis.exe does not work well on IIS 7.0 (even with IIS 6.0 support installed) caused the "The error indicates that IIS is not installed on the machine .." exception what means you need to use server features to install it instead of command line

The quickest solution here is to update ASPNET by using the features - with no changes on application pool go to server roles, uninstall and then install again ASPNET. Both the issues will be fixed.

• Can you have IIS 7.0 on Windows 2008 Core: yes (with several limitations)
• Can you install .NET Framework: no (hilarious, but, no)
• Can you install Microsoft SQL 2005: still no

• Can you install ASP.NET : no
• Can you install Microsoft SharePoint: no
• Can you install PowerShell: no

Excelent book about WWF (See Michael's review there: "Foundations of WF" Book Review )

Foundations of WF: an Introduction to Windows Workflow Foundation (Expert's Voice in .Net) by Brian Myers

Must read for anyone who wants to begin

There are some extra useful resources can helps you reach the WF:

• http://wf.netfx3.com/ - The headquartes of Workflow Foundation
• Windows Workflow: The Base Activity Library - Cool all-round article describes applied usage of all WF activities.
• Hello Workflow - Windows Workflow Foundation key concepts a screencast of helloword in WF
• And Introduction to Developing with Windows Workflow Foundation and Visual Studio 2005 to pass a free-pay Microsoft course about WF.
• The next reading stage of WF is BPEL for Windows Workflow Foundation (March CTP), coz what is the WF without BPEL
• Getting Started with Microsoft Windows Workflow Foundation: A Developer Walkthrough - General overview
• Hello, WF! (Description of activities with samples)
• Windows Workflow Foundation (Sample of using WF with Windows Forms)
• Windows Workflow Foundation, Part 2 (Sample of using WF with ASP.NET)
• Performance Characteristics of Windows Workflow Foundation
• Windows Workflow Foundation vs BizTalk Server
• The article about Windows Workflow Foundation vs BizTalk Server 
• Resource lists: 1 2 3
  
  Crossposted from devkids.blogspot.com

Model View Presenter vs Model View Controller 

Intro
In my work I often deal with the situation when people use MVС/MVP patters without clear understanding the really difference between them. In this article I will try to explain my view on the issue.

 It’s important to understand that in n-tier systems MVP/C patterns are responsible for the presentation layer only. It’s not about how you build data or services layers, it’s about separating the data (model) and the user interface(view), telling you how the user interface communicates with data. Using these patterns gives your application independence on changing presentation without depending on data and controlling logic.

 Generally:

1.       Model means data & business logic model. It’s not always a DataSet, DataTable or such stuff. It’s kind of components or classes which can provide data and can receive the data to store it somewhere else. To simplify understanding of Model just think about it as “Façade” class.
2.       View represents data for the user. Generally it’s just the UI, and not always UI logic. For example in ASP.NET the page with controls is View.  The View can receive data directly from Model, but View never updates Model.
3.       The Presenter/Controller contains the logic to update Model regarding the user’s actions into the View. View only notifies Controller about user’s actions. Controller extracts data from View and sends it to Model. 

The main point of the MVC/P pattern is to split Model from View/Controller to make Model independent from them. So, Model cannot contain the references to the V/C.

 What is the MVC (model-view-controller)?
1.       Controller initializes the events of View interface to interact with model and controller.
2.       The user interacts with View (UI).
3.       Controller handles user’s events (can be the “observer” pattern) and asks Model to update.
4.       Model raises events, informing subscribers (View) about changes.
5.       View (UI) (subscribes to model events) handles Model’s evens and shows new Model’s data.
6.       The User Interface waits for the further user actions.

Primary points are:

1.       View does not use Controller to update Model. Controller handles the events from View to manage user’s interaction and data (via interaction with Model)
2.       Controller can be combined with the View. It’s what the Visual Studio do for the Windows Forms by default. The primary point is logical separation of Model from the View.
3.       The Controller do not contains the rendering logic.

The example below illustrates the “Active-MVC” pattern, also known as “the original MVC pattern”.
                                                                                                                    

 There is also the “Passive-MVC” pattern.

 The differences are that:
-         Model knows nothing about Controller and View, it only used by them both.
-         Controller uses View asking it to render new data.
-         View uses Model to get the data only when Controller ask View about it (no subscription between View and Model).
-         Controller handle Model data changes.
-         Controller may contain the rendering logic for the View.

And now we are close to MVP pattern.
MVP is like an MVC, but View doesn’t use Model.

In the MVP View and Model are utterly separated from each other using the Presenter. Any interaction between View and Model take place in Presenter. 

Presenter is like the Controller, but which:
1.       handles the user events from View (in MVC View handles this events);
2.       updates Model using updated data from View (MVC passive just informs View to get/set new data from Model and MVC active takes no role in it, because Model informs View);
3.       examines Model for changes (like the MVC passive);
4.       (the main difference from MVC) gets Model data and stores them into View;
5.       (the main difference from MVC active) notifies View about updates;
6.       (difference from MVC) renders View using the Presenter

So, MVP has following pros:
1.       Model is separated from View and we can change View independently from Model
2.       We using Model more effective, because all interactions are now in one place –in the Presenter(Controller)
3.       We can use one Presenter(Controller) for many Views without changing the Presenter(Controller) logic, it’s can be useful because View changes more often than the Presenter(Controller)
4.       If we are storing View logic in the Presenter(Controller) we can test the logic independent of user interaction (Unit Testing)

But there are cons:
1.       Too many interactions between View and Presenter because rendering View data is in the Presenter;

Also you need to understand that if you render too much data for View you are tied up on the particular View. So if  View needs to be changed you need to update the Presenter either, For example, if you rendered html and need to render the pdf, there is a big possibility that View need to be changed too. 

• LINQ May 2006 CTP preview: here
• Books: LINQ for Visual C# 2005
• Charlie Calvert's Community Blog: here
• C# 3.0 Specification (September 2005): here (ms .doc)
• Concepts behind the C# 3.0 language by Tomas Petricek: here