Web Development Using ASP 'NET

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Web Development Using ASP .NET
Welcome to week 2 of

• CA 240
• Kashif Jalal

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ASP .NET Introduction

• ASP.NET is the latest version of Microsoft's
  Active Server Pages technology (ASP).
• Before you continue you should have a basic
  understanding of the following
• World Wide Web WWW
• HTML and the basics of building Web pages
• Scripting languages like JavaScript or VBScript
  the basics of server side scripting

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What is ASP?
ASP is a server side scripting technology that
enables scripts (embedded in web pages) to be
executed by an Internet server.

• ASP is a Microsoft Technology
• ASP stands for Active Server Pages
• ASP is a program that runs inside IIS
• IIS stands for Internet Information Services
• IIS comes as a free component with Windows 2000
• IIS is also a part of the Windows NT 4.0 Option
  Pack
• The Option Pack can be downloaded from Microsoft
• PWS is a smaller - but fully functional - version
  of IIS
• PWS can be found on your Windows 95/98 CD

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What is an ASP File?

• An ASP file is just the same as an HTML file
• An ASP file can contain text, HTML, XML, and
  scripts
• Scripts in an ASP file are executed on the server
  
• An ASP file has the file extension ".asp"

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What is ASP .NET?

• ASP 3.0 is the latest version of ASP, but there
  will never be an ASP 4.0 version.
• ASP.NET is the next generation ASP, but it's not
  an upgraded version of ASP. ASP.NET is an
  entirely new paradigm for server-side ASP
  scripting.
• ASP.NET is a part of the .NET Framework.
  Microsoft spent three years rewriting ASP.NET
  from the ground up, and ASP.NET is not fully
  backward compatible with ASP 3.0.

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The .NET Framework

• The .NET Framework is the infrastructure for the
  Microsoft .NET platform. 
• The .NET Framework is an environment for
  building, deploying, and running Web applications
  and Web Services.
• The .NET Framework contains a common language
  runtime and common class libraries - like
  ADO.NET, ASP.NET and Windows Forms - to provide
  advanced standard services that can be integrated
  into a variety of computer systems.
• The .NET Framework provides a feature-rich
  application environment, simplified development
  and easy integration between a number of
  different development languages.
• The .NET Framework is language neutral. Currently
  it supports C, C, Visual Basic, and JScript
  (Microsoft's version of JavaScript).
• Microsoft's Visual Studio.NET is a common
  development environment for the .NET Framework.

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Brief History of Server-Side Programming
Technologies

• Common Gateway Interface (CGI)
• Internet Server Application Programming Interface
  (ISAPI)
• Internet Database Connector (IDC)
• Active Server Pages (ASP)
• ASP .NET

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Common Gateway Interface (CGI)

• One of the first technologies to be introduced
  built into almost all Web servers
• CGI is a method of obtaining and returning
  information to and from the Web server
• CGI, as its name implies, isnt a language, but
  rather an interface to the Web server
• CGI applications can be programmed in a wide
  variety of languages. Possibly the most common is
  Practical Extraction and Report Language (Perl),
  C, Python
• Definite advantages of CGI are that it is
  platform independent and built into most Web
  servers
• Possibly the greatest pitfall of CGI from a
  performance point of view in Windows is that each
  client request for a CGI Web page requires a
  new process to be created, which consumes vast
  amounts of system resources

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Internet Server Application Programming Interface
(ISAPI)

• Microsoft developed (ISAPI) for its Internet
  Information Server (IIS) to eliminate the major
  performance bottleneck of CGI the need to create
  a new process for each client request.
• ISAPI was intended to replace CGI for IIS by
  allowing developers to do everything they could
  by using CGI executables, but do it with
  significantly less performance overhead.
• ISAPI applications are compiled as Windows
  dynamic link libraries (DLLs).
• ISAPI applications run in the IIS process space,
  which allows for execution faster than that of
  CGI applications.
• There are two different types of ISAPI
  applications, ISAPI Filters and ISAPI Extensions
• ISAPI Filters run in the background and can
  monitor Web server requests and perform a variety
  of tasks accordingly
• ISAPI Extensions are the rough equivalent of CGI
  executables and run upon client request.

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Internet Database Connector (IDC)

• Microsofts Internet Database Connector (IDC)
  technology has been included in IIS since its
  inception and is used to provide easy database
  connectivity for Web pages
• Each page requires two files a query file and a
  template file
• The query file contains the database connection
  information and the SQL query.
• The template file contains HTML and tags denoting
  where specific data from the query file must be
  inserted
• This method of database connectivity was very
  easy to use, but it had one major pitfall in that
  there was no place to put business logic

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Active Server Pages (ASP)

• Microsoft combined the best features of IDC and
  ISAPI to produce Active Server Pages (ASP)
• ASP pages offer the ease of use of IDC by
  allowing database and business logic code to be
  inserted directly into pages using special tags,
  and they offer the performance advantages of
  ISAPI
• ASP is very scalable, and this has been proven
  time and time again with many large sites relying
  on ASP
• ASP was a huge leap forward and offered a
  completely new paradigm for dynamic Web page
  development when it was introduced
• ASPs unique approach allowed for dramatic
  increases in productivity and opened up the
  exciting area of dynamic Web page development to
  many novice programmers who were bewildered by
  the complexity of CGI and ISAPI
• This was helped largely by the fact that the
  primary languages for ASP development are
  VBScript and JScript

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ASP .NET

• ASP.NET isnt simply the next version of
  ASPits a completely redesigned technology that
  takes the best aspects of ASP and merges them
  with the power of pure object-oriented
  programming (OOP), a powerful development
  framework with features like
• A fully compiled environment.
• An integral part of .NET and the .NET Framework.
• Server controls
• Event driven programming
• Separation of code from content
• Session state management
• User input validation
• Web services
• Caching services
• Security
• Debugging and tracing
• Deployment

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Visual Studio .NET IDE Layout