Server side technologies ASP.Net

Amelina Ahmeti, Sultonmamad, Usman

Web Technologies – Prof. Dr. Ulrik Schroeder – WS 2010/11 1 The slides are licensed under a

Creative Commons Attribution 3.0 License

Overview

ASP.Net v/s PHP

The need for ASP.Net

Introduction to ASP.Net

.Net Framework

.aspx and Code Behind files

Page Life Cycle

Controls

State Management

Configuration Files

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Objectives

Introduction to ASP.Net

Basic Advantages

Some Examples

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Comparison with PHP

Wide belief that PHP is faster

ASP.Net is a platform

Cost

Web Server

Propriety

JIT (Just In Time) Compilation

Discussed in Detail Later!

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ASP – Active Server Pages

Server-side scripts

Also client-side scripts

Validate user inputs

Access database

ASP provides solutions for transaction processing and managing session state.

One of the most successful languages for Web development.

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Problems with ASP

Interpreted and Loosely typed code Late binding of Variables

Uses Jscript or VBScript

Mixes layout (HTML) and logic (scripting code)

Frequent switches between HTML and ASP code

Hard to separate Content and Business Logic

Limited Development and Debugging Tools

Visual InterDev, Macromedia helped

Debugging done using “Response.Write()”

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Problems with ASP No real state management

Process Dependent

Server Farm Limitations

Cookie Dependent

Update files only when server is down

To update components based site you have to stop the server

If not Application fails

Obscure Configuration Settings

Configurations stored in IIS Metabase

Difficult to port application

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ASP.Net – Issues to Address

Make sure ASP runs fine

Since ASP was widely used

Had a very large programmer base

Introduction of .Net Framework

ASP.DLL not modified while installing framework

IIS could run ASP and ASP.Net simultaneously

Overcome the short comings in ASP

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ASP.Net - Advantages

Support for compiled languages

Separation of Code from HTML

Use services provided by the .NET Framework

Easier Debugging using Visual Studio

Graphical Development Environment

Session Management

Update files while the server is running!

XML-Based Configuration Files

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ASP.Net - Overview

Server side technology

Web Forms used to build Web Applications

Provides services to create and use Web Services

Controls

HTML Controls

Web Server Control

User Controls

Ease of application development

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.Net - Framework

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ASP.Net - Files

A simple ASP.Net file consists of two files Presentation (.aspx)

Code Behind (.aspx.cs for C#)

Web Services have the extension .asmx

Configuration Files

Global.asax (also has a code behind file)

Optional file containing global logic

Also has a code behind file

Web.config

Application Configuration file

Allows defining Name, Value pairs that could be accessed by application

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Preserving Data Across Pages

Session

InProc

StateServer

SqlServer

Cookies

Query String

Cookie Independent (Visual Studio 2010)

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Execution Cycle

Request aspx page

ASP.Net runtime parses file for code to be compiled

Generation of Page class (ASP.Net Page)

Instantiates server controls

Populates server controls

Rendering of Controls

Send the HTML to client browser

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Execution Process

Compiling the code First time request

Code compiled to MSIL(Microsoft Intermediate Language) Similar to Assembly Language

Used to achieve platform independency Not the target what Microsoft wants

CPU independence

Efficient conversion to Native code

CLR(Common Language Runtime) compiles the code

A copy of Page is Cached Used until changes are made to the page, and it needs to be compiled again

Updating the page causes a re-build

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Page Life Cycle

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ASPX Page Requested

Request

Page Start

Initialization

Load

Post Back Event Handling

Rendering

Unload

<html> …

</html>

Web Browser

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Just-In-Time Compilation

ASPX File

Code Behind

Page Class File

ASPX Engin

e

Page Class

Request #1

Request #n

Courtesy: Patrick

Stalljohann

ASP.Net Controls HTML server controls

HTML elements programmable in server code.

HTML tags are left as is by compiler

Web server controls

Defined as Abstract controls

Have more built-in features than HTML controls e.g. Calendar, Menus etc.

Validation controls

Perform client side validation

Can be used to build own validators

User controls

Controls created by the User as ASP.Net webpages

Re-usability and Power to User.

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Global.asax

Declare application level Events and Objects

Code for events like

Application Start

Application End

Session Start

Session End

Since this code cannot be placed in application itself

Also used for Application and Session State Management

Compiled just like any other ASP.Net page

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Web.config

Stores configuration information in XML format

Optional

Allows for creating Name, Value pairs that could be accessed by the web application to apply configurations

Portable

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References www.w3schools.com

www.codeproject.com

msdn.microsoft.com

CiL – Center for Innovative Learning Technologies, RWTH Aachen University

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