The Web Architecture and ASP.NET

Slide 2 Review of the Web (1) It began with HTTP and HTML, which delivers static Web pages to browsers which would render those pages Browser Web Server HTTP Request HTTP Response (Web page)

Slide 3 Review of the Web (2) Scripting languages were created to execute client code within the context of a browser Browser Web Server HTTP Request HTTP Response (Web page / code) Client code (JavaScript) (VBScript)

Slide 4 Review of the Web (3) Server-side applications were created to execute code and dynamically generate Web pages based on a particular request Browser Web Server HTTP Request HTTP Response (Web page / code) Client code (script) Interpret request Generate HTML and script

Slide 5 Review of the Web (4) And now we have AJAX / JSON making partial page requests Browser Web Server HTTP Request HTTP Response (Web page / code) Client code (script) Interpret request Generate HTML and script Execute AJAX Request Client code (Silverlight)

Slide 6 The Great Client/Server Debate Where do we process? Client or server What get’s processed where? And the interaction between client and server Where does bandwidth fit into this equation? Where does processing power (and latency) fit into this equation?

Slide 7 And all the Related Technologies jQuery – yes it works with ASP AJAX – ASP has some interesting AJAX libraries We can (AND WILL) write our own handlers for those AJAX requests Silverlight is a well-used client-side framework part of RIA ( us/library/ee707344(v=vs.91).aspx) us/library/ee707344(v=vs.91).aspx Azure?

Slide 8 Current Client Technologies And what browser (and version) do you use? Scripting details vary from browser to browser DOM objects can vary a bit too HTML5 and CSS3 support varies but is pretty good

Slide 9 Current Server Technologies Apache WebSphere (IBM) Oracle / Sun (doing ASP.NET, CGI and PHP) Microsoft and IIS HP and others have offerings Largely based on Apache In summary, there are quite a few

Slide 10 ASP.NET (History) Introduced with the.NET Framework in 2002 It made Web development look like traditional Windows development ASP.NET 2.0 introduced in 2005 gave developers enhanced database tools This included desktop improvements too MVC was introduced / much more later ASP.NET 3.0 released with 2008

Slide 11 ASP.NET (History) ASP.NET 4 released with Visual Studio 2010 and version 4 of the Framework Razor was introduced along with ASP.NET Web pages Web pages and Web Forms are different There is an open-source movement (We will see how this pans out) Support for HTML 5 and CSS 3 is very good

Slide 12 ASP.NET (History) Current version is Visual Studio 2013 and Framework version 4.5.1

Slide 13 ASP.NET (Architecture)

Slide 14 What is a.NET Application (1)? It looks and works surprisingly like Java Source code (VB, C#, etc.) is compiled into a machine independent assembly language (MSIL or IL) The executable file is called an assembly IL can be disassembled using the IL Disassembler (ILDASM)

Slide 15 What is a.NET Application (2)? MSIL is translated into native executable code via the Just-in-Time (JIT) compiler It’s possible to precompile an application using the Native Image Generator (Ngen) All.NET applications run under the control of the Common Language Runtime (CLR) We call this managed code

Slide 16 What is a.NET Application (3)? On the desktop, the application runs under the control of the Common Language Runtime With Respect to Web applications, all execution is handled on the server (IIS) us/library/bb aspx us/library/bb aspx

Slide 17 The ASP.NET Runtime When IIS sees an.aspx file, it loads aspnet_isapi.dll to create the Page object Application behavior is controlled by configuration files Machine.config is the global machine configuration file Web.config allows you to override default configuration items Both are XML documents

Slide 18 Programming ASP.NET Conceptually it’s much like the VB programming you are used to You create procedures in event handlers and general procedures You declare variables Instead of a form, the primary user interface is the WebForm

Slide 19 Current ASP Technologies ASP Web Forms Have been around for a while and have continued to evolve ASP.NET MVC It stands for Model-View-Controller It’s an alternative to Web Forms ASP.NET Web Pages (Razor) A more lightweight processing model Looks a bit like PHP Silverlight and RIA

Slide 20 ASP.NET Web Forms Provides server-side tools for site navigation Menus, Drill-down toolbars, breadcrumbs, etc. Authentication tools Database connections Client and server executable code State management and caching Authentication and role management Deployment tools Robust development tools (Visual Studio)

Slide 21 ASP.NET Web Forms (Introduction) Client (browser) HTTP Server (IIS) ASP Worker Process request Generate client page (HTML) request response

Slide 22 Web Forms and Stateful Web Programming Remember that the Web is stateless Web servers to not persist state from one request to the next ASP.NET does allow stateful programming though various hidden fields and serialized data server side session objects Much more on state management later

Slide 23 Web Forms and Event-Driven programming ASP.NET, though serialization, simulates event-driven programming ASP.NET events differ significantly from Windows Forms events

Slide 24 Introduction to the Web Forms Component Model Remember that.NET is an OOP environment and ASP.NET is no exception As the developer, you create.aspx pages that make up a Web application When executed, the.aspx page is compiled into a custom class that inherits from System.Web.UI.Page As the developer, you can program against this class just as you would program against any class It all happens on the server!

Slide 25 ASP.NET MVC MVC is the acronym form Model-View- Controller It’s a design pattern coined by the GOF It requires version 4 of the.NET Framework It’s an alternative to traditional ASP.NET Web forms

Slide 26 Web Matrix and Razor A “lightweight” technology to create simple Web sites Requires version 4.0 of the.NET Framework and a few add-ins

Slide 27 Silverlight It run on a client (browser) and communicates with a server via RIA services Netflix?