PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Accessing Form Variables
23
For a full list of formats supported by date(), see Chapter 21,“Managing the Date
and Time.”
Accessing Form Variables
The whole point of using the order form is to collect customers’ orders. Getting the
details of what the customers typed is easy in PHP, but the exact method depends on the
version of PHP you are using and a setting in your php.ini file.
Short, Medium, and Long Variables
Within your PHP script, you can access each form field as a PHP variable whose name
relates to the name of the form field.You can recognize variable names in PHP because
they all start with a dollar sign ($). (Forgetting the dollar sign is a common programming
error.)
Depending on your PHP version and setup, you can access the form data via variables
in three ways.These methods do not have official names, so we have nicknamed them
short, medium, and long style. In any case, each form field on a page submitted to a PHP
script is available in the script.
You may be able to access the contents of the field tireqty in the following ways:
$tireqty
$_POST[‘tireqty’]
$HTTP_POST_VARS[‘tireqty’]
// short style
// medium style
// long style
In this example and throughout this book, we have used the medium style (that is,
$_POST[‘tireqty’]) for referencing form variables, but we have created short versions
of the variables for ease of use. However, we do so within the code and not automatically,
as to do so automatically would introduce a security issue within the code.
For your own code, you might decide to use a different approach.To make an
informed choice, look at the different methods:
n Short style ($tireqty) is convenient but requires the register_globals configuration
setting be turned on. For security reasons, this setting is turned off by
default.This style makes it easy to make errors that could make your code insecure,
which is why it is no longer the recommended approach. It would be a bad
idea to use this style in a new code as the option is likely to disappear in PHP6.
n Medium style ($_POST[‘tireqty’]) is the recommended approach. If you create
short versions of variable names, based on the medium style (as we do in this
book), it is not a security issue and instead is simply on ease-of-use issue.