Lesson 12

In this module, we have covered the ASP features that support the browser and server dialog. The ASP Request object retrieves and accesses the information the browser sends. The forms of the ASP Response object all send the various types of server replies back to the browser.

Cookie data, query string data, and HTML Form data are all available to the server and give you many ways to get information from users. Cookies enable you to store small amounts of data on a user's hard drive and then retrieve the values when the user returns to the website. Query strings let you use a URL to pass data from one Web page and ASP script to another. Forms can contain more complex user data and data that will be processed by a Web application. Lessons still to come will explain how to handle multiple visitors on your Web site and how to perform more complex interactions between ASP scripts on different Web page. Adding to what you learned in the last module, the information and techniques contained in this module bring greater interactivity to your website. In addition to the ability to display text and calculate values dynamically, your site can now respond differently to different visitors by "remembering" information provided by that visitor at an earlier time.

This module introduced you to the following terms:

1. Array: A placeholder which can hold more than one value. A variable that stores other variables in a particular order. Each variable in an array can be accessed by its index. For example, SomeArray[12] is the element at index 12. Some languages number arrays from 0, whereas others start at 1. Thus, SomeArray[12] could be the 12th or 13th element depending on the array's first element.
2. Collection: A variable that can be accessed either by index (like an array), or by key. In Perl, a collection is called an associative array.
3. Cookie: A small chunk of data that is initially sent by a server to be stored on a client's machine. Subsequent requests from that client are sent along with previously-defined cookies and their values. For example, a user's username and password might be stored in cookies, so that the user does not have to enter them every time to access a protected resource.
4. Event: Things that happen in the world and are recognized by a program or object. For example, a mouse click is an event recognized by some objects but not others.
5. HTTP headers: Additional information which is sent back and forth between a Web client and HTTP server. The additional information might include the last modified date of a file sent by a server, or a cookie sent by a client. In a Web response (sent by the server) the headers are sent before any HTML.
6. Index: When referring to arrays or collections, the index identifies the element within the array or collection. For example, an array of T-shirts could be referenced by index as concertShirts(11), which is the item at index 11 in the array. Occasionally, index will be used to refer "the index file" of a Web server directory. The index file (usually either index.html on Unix, or Default.htm on Windows) is the file returned when a browser requests the directory which the index file resides in, rather than any particular file within the directory. For example, http://some.webserver.com/catalog/ will usually refer to the index file (for example, index.html) within the catalog directory.
7. Key: A key specifies a particular element within a collection. For example a collection of first names might use a last name as a key, and Bill Smith first name could be retrieved with: FirstNames("Smith")
8. Property: A characteristic of an object. For example, a Font object might have a Size property, which would store the point size of the Font. Although some properties are read-only, many properties can both be read and set to new values.
9. Query string: The portion of a URL which follows the question mark character (?), which is usually used to pass additional information to the server. For example, a search string could be sent to the URL of a search engine as the query string within a URL.
10. Request object: An ASP built-in object which represents the client\'s request to the Web server, and includes such items as cookies and information on the client's browser.
11. Response object: An ASP built-in object which represents the Web server\'s response to a client's request, and includes such items as the last modified date for a requested page and new cookie values.
12. Server object An ASP built-in object which represents the Web server. The server object's most important job is to create new objects (other than the ASP built-in objects). For example, the CreateObject() method enables you to build an ADO object from the ADO Component, which can then be used for database access within a script.

The next module discusses how ASP maintains information for a user throughout a session and how to use ASP's Ad Rotator component.

Click the Quiz link below to test your knowledge of the response and request objects.
Response Request Object - Quiz