Perl - State and Cookies

State and Cookies - Perl module P407

Each time you submit a form to a web server using CGI, you start a new program with new variables, and when the server has sent you back its response, that program exits, with a loss of all data in memory. That's fine for a one-screen application, but in practise you'll want to string together a series of forms to make up a shopping application, a bulletin board, or another application. To do this, you'll need to "maitain state" and there are various ways of doing this, which this important module studies.

This topic is presented on public course Using Perl on the Web

Examples from our training material

sweet.pl	Perl, CGI, sessions - application template, first principles
sweeter.pl	Perl, CGI, sessions - complete application template second steps
sweetest.pl	Perl, CGI, sessions - complete application template, full demo

Background information

Some modules are available for download as a sample of our material or under an Open Training Notes License for free download from http://www.training-notes.co.uk.

Topics covered in this module

The need for non-transient data.
Multiple users.
Schemes for maintaining state.
Which scheme should I use?.
Central database example.
Our database server.
Planning our application.
How it fits together - entry to the site.
The next page.
Modules used.
Persistent cookies.
Shopping cart using hidden fields - example.
Shopping cart using cookie - example.
Templating system.
Security considerations for server side applications.
1. Tainting.
2. Regular expressions from user.
3. validate via email.
4. Data in hidden directories.
5. Credit card info in cookies.
6. https.
7. Avoid \ etc..
8. Temp file names.
9. Save before send.
10. tr.

Complete learning

If you are looking for a complete course and not just a information on a single subject, visit our Listing and schedule page.

Well House Consultants specialise in training courses in Python, Perl, PHP, and MySQL. We run Private Courses throughout the UK (and beyond for longer courses), and Public Courses at our training centre in Melksham, Wiltshire, England. It's surprisingly cost effective to come on our public courses - even if you live in a different country or continent to us.

We have a technical library of over 600 books on the subjects on which we teach. These books are available for reference at our training centre. Also available is the Opentalk Forum for discussion of technical questions.