| Maintaining persistent (session) data |
(Embperl 1.2 or above) While hidden fields are useful when working with forms, it's often
necessary to store persistent data in a more general way. Embperl
utilizes Apache::Session to do this job. Apache::Session is caple
of storing persistent data in memory, in a textfile or in a database.
More storage methods may supported in the future. While you can simply
call Apache::Session from an Embperl page, Embperl can do it for
you. All you need to do is to put your data in the hash %udat. The
next time the same user requests any Embperl page %udat will contain
the same data. You can simply use this to keep state information for
the user. Depending on your expire settings, the state can also kept
between mulitiple sessions. A second hash, %mdat, can be used to
keep a state for one page, but for multiple users. A simple example
would be a page hit counter: The page is requested [+ $mdat{counter}++ +] times
since [+ $mdat{date} ||= localtime +]The above example counts the page hits and shows the date when the
page is first requested. You don't need to worry about performance -
as long as you don't touch %udat or %mdat, no action is taken.
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