Computer Networks
Tutorial #22
- What is a shopping cart application?
- What is meant by state maintenance in the context of
a shopping cart application? What are the two technologies
which can be used to implement state maintenance?
- Typically, what information do you think would be contained within
a hidden field or cookie? There are a couple of ways you can think about
this question, depending on how much of the "state information" is
maintained at the server, and how much on the client side (browser)
software.
- What are some of the advantages of cookies over hidden fields?
What disadvantages do they have?
- Under what conditions is a cookie stored on a client system's local disk
between "browser sessions"?
- Discuss the security implications of cookies. In particular, if someone
asked you whether it's safe to accept cookies from Web servers, what would
you tell them, and why?
- On many Web Commerce sites (for example,
Amazon.com and
CDNow.com), cookies are used to
"authenticate" repeated visits to the site. For example, if you have
"shopped" at either of the above sites, they will set a cookie
so that you can subsequently "one-click" (or somesuch) to order. It's
obviously important that no one else can generate your
cookie, and this probably involves some use of encryption.
How could this be implemented?
- (Hard) What controls do the
domain
and path
specifiers impose on when your browser sends a cookie to a server?
In other words, how are the domain
and path
specifiers interpreted in the browser?
- (Discussion question) There's obviously lots of potential for using
Java and/or Javascript to build a shopping cart application which runs
on the client (browser) instead of using FORMS and CGIs. Is this a good
idea? Why, or why not?
See Prac #22 for the practical exercises
accompanying this tutorial.
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Copyright © 2000 by
Philip Scott,
La Trobe University.