There are two major components of Active Server Pages along with five built-in software objects that permit creation of data-driven Web pages. These components and objects provide a comprehensive set of properties, methods, and collections that the developer can use to help carry out information processing tasks.

• Object properties are their settings or characteristics. Properties can be read and written to access or change their settings.



• Object methods are their actions. These methods are used to activate the object to perform processing functions.



• Object collections are their data sets. Certain objects encapsulate sets of data that are used within processing operations.

The primary set of components and objects within the ASP environment are shown in the following illustration:

Scripting Component

The Scripting Component contains the scripting languages used to create server-side processing scripts along with other objects through which the server's directory and file structures are accessed.

VBScript. The VBScript (Visual Basic Scripting Edition) language is the default language used to create scripts. VBScript is a subset of Visual Basic, yet it contains the functionality needed to produce dynamic, data-driver Web sites in a fairly easy-to-learn, easy-to-apply manner. In addition to providing much of the functionality of standard programming languages, VBScript is the vehicle for activating other objects within the ASP environment.

File System Object. One of these objects is the File System Object. This object is created to provide a set of properties and methods for working within the directory system of the server. Through the File System Object you can manipulate folders and files by creating them, naming them, moving and copying them, deleting them, and performing other functions related to managing the folders and files of your Web site.

Text Stream Object. In addition to working with directories and their contents, the File System Object is used to create Text Stream Objects. These objects are used to read and write text files. Through the Text Stream Object, you can pull information from text files and display it on a Web page, assuring that the page always contains the latest information as reflected in the contents of the files. Or, information collected through a Web page form can be used to update existing text files, thereby assuring the currency of information stored in text files.

Active Data Objects (ADO) Components

There are two primary ActiveX Data Objects (ADO) through which links are made to databases and through which information is read from or written to database tables.

Connection Object. Connection Objects include the properties and methods for linking scripts with databases. These connections are established through ODBC (Open DataBase Connectivity) drivers that are associated with various types of database management systems. There are ODBC drivers for the popular DBMSs such as Microsoft Access, Microsoft SQL Server, and Oracle. Therefore, scripted Web pages can gain access to most of the Database Management Systems on the market.

Recordset Object. Recordset Objects represent the contents of databases linked to through Connection Objects. It is through Recordset Object properties and methods that access is provided to the tables of a database and through which you can read from, write to, and update the contents of these tables.

ASP Built-in Objects

In addition to the scripting and data access components there are five built-in ASP objects that provide functionality for the Web page author:

Server Object. The Server Object is the mechanism through which VBScript creates File System Objects, Connection Objects, Recordset Objects, and other objects need by the script.

Request Object. The Request Object is used to access data sent from the browser, most often transmitted from forms appearing on the Web page.

Response Object. The Response Object is used by a script to send information from the server to the browser. Information appearing on a Web page is produced by the Response Object.

Session Object. The Session Object is used to manage user sessions. A session is established when the user first arrives at a Web site and Session Objects can be used to track activities of users as they navigate through the site.

Application Object. The Application Object is used to manage the entire Web application. It is used to keep track of users or to maintain information pertinent to all visitors to the site.

Much of the scripting necessary to process data on the server involves calling upon these ASP objects to read or set their properties, activate their methods, or access their collections of data. These objects provide a wide range of functionality and remove from the Web developer the need to code detailed instructions to accomplish the tasks. Most of this tutorial, in fact, is coverage of these objects and the properties, methods, and collections available to perform information processing activities.