Transcript wk-2
Welcome to week – 2 of… Web Development Using ASP .NET CA – 240 Kashif Jalal Kashif Jalal CA-240 (072) 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 Kashif Jalal CA-240 (072) 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 Kashif Jalal CA-240 (072) 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" Kashif Jalal CA-240 (072) 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. Kashif Jalal CA-240 (072) 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. Kashif Jalal CA-240 (072) 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 Kashif Jalal CA-240 (072) 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, isn’t 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 Kashif Jalal CA-240 (072) 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. Kashif Jalal CA-240 (072) Internet Database Connector (IDC) • Microsoft’s 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 Kashif Jalal CA-240 (072) 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 ASP’s 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 Kashif Jalal CA-240 (072) ASP .NET ASP.NET isn’t simply the next version of ASP—it’s 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 Kashif Jalal CA-240 (072) Visual Studio .NET IDE Layout Kashif Jalal CA-240 (072)