Win 32 and WEB applications
What is an application programming interface (API)? by definition an API is a group of procedures, data structures, object classes and set of rules made available by libraries and/or operating system services to support the construction of applications. Application programmers using earlier versions of windows like windows 1. 0 had tedious work of writing many lines of codes for simple application programs like the Hello word which outputs the word Hello on a users Visual display unit (VDU).
Alterations and additions have been witnessed in the later versions of windows operating system. Windows Application programming interface has also undergone a considerable amount of change and earlier versions of windows Application programming interface such as the windows API for Windows 1. 0 supported 450 function calls while the latest Windows APIs supports thousands of function calls. Windows releases have been able to maintain interface consistency; i. e old windows applications will still resemble the modern windows application programming interfaces.
The main change in the windows application programming interface however, is the change from Win 16 API which was in windows 3. 1 and other windows earlier versions to Win 32 API which was contained in windows NT and windows 95 and other later versions of windows operating system (Villan , 1999, p. 15). Definitions Win 32 is an application programming interface that is found in Windows 95 and Windows NT and other later releases of windows operating systems. Applications that rely on the Win 32 application programming interface are able to run well in all the windows environments.
A Web application simply refers to a program that can be accessed using a Web Browser over a network such as the internet or an intranet. It is written in browser supported language such as HTML, PHP, VB script etc. The Web application code is dependant on a common web browser for its program execution. Web applications are made popular by the ease of use of a web browser client. Also WEB applications are easily kept up to date and maintained without the need of installing software on client computers. Examples of WEB applications include E-mails, E-commerce sites etc (Hart 1997).
How it works This research will mainly try to discover how Win 32 application programming interface aids in the development of WEB applications; that is packages available in Win 32 API that assist a Web application programmer develop web applications (http://aspell. net/win32/). Before embarking on the issue of WEB applications its important to have a general view of some of the functionalities provided by the windows application programming interface. The functions of the windows API can be categorized into eight categories.
One of the categories is the base class which mainly provides access to important resources found in the windows system this may include files, devices and processes. The other category is the advanced services; this category offers services such as windows shutdown restart system, manage user accounts etc. The Graphics device interface category is mainly responsible for the output of graphics to output devices such as display units, printers etc. The user interface category creates and manages and common controls which include buttons and spool bars.
The user interface category also accepts mouse and keyboard input (Spinellis 1998). Common dialog box library is also another category and it provides programs with average dialog boxes which offer a user with the option of opening and saving files and choosing color and font. Common control library category gives programs access to more complex controls which include status bars, progress bars, toolbars and tabs. Windows shell category provides access to programs to access functions offered by the OS shell. Network services category gives access to networking capabilities of the OS (http://search.
cpan. org/~robertmay/Win32-GUI-1. 06/docs/GUI/Tutorial/Part3. pod). The Internet explorer is a web browser; it gives us insight of the many APIs that are used by WEB applications. Internet Explorer has provided Web applications with services since the advent of windows 98. Some of the services provided by the internet explorer which is considered as part of the Win 32 application programming interface include. A web browser control enclosed in mshtml. dll. Mshtml. dll refers to the rendering engine of Microsoft windows version.
Later versions of internet explorer have made alterations to the rendering engine so as to make keep up with WEB standards and support new technologies. The work of a rendering engine is taking marked up language formatting it and then displaying the content on the visual display unit of a user or on a printer (Mart, 2001, p. 52). The other service is the uniform resource locater (URL) service which is contained in the urlmon. dll package. It helps applications in resolving Uniform resource locaters by providing Component object model (COM) elements to the WEB applications.
The internet explorer also offers library services which provide multi language. Other services will include DirectX transformations, XML language support and lastly access to windows address book (Abdulla, 1998, p. 119). The packages available in Win 32 API are invoked by remote procedures of the WEB applications being developed. This enables the programmer to use code provided by the Win 32 API to enable his WEB application access functions provided by the Win 32 API (Abdulla, 1998, p. 117).