NAME
Apache::Action - A method dispatch mechanism for Apache
SYNOPSIS
# An Apache handler to manage the cycle.
package My::Apache::Handler;
my $ah = new HTML::Mason::ApacheHandler...);
sub handler {
my ($r) = @_;
...
tie %SESSION, 'Apache::Session::....';
my $state = new Apache::Action::State( # Or custom state class
Request => $r,
Session => \%SESSION,
);
my $action = new Apache::Action(
Request => $r,
Session => \%SESSION,
State => $state,
);
my $status = eval { $action->run; };
if ($@) { $state->error($@); $status = SERVER_ERROR; }
unless ($status == OK) {
my $subreq = $r->lookup_uri('/error.html');
$r->filename($subreq->filename);
}
return $ah->handle_request($r);
}
# A set of action handlers
package My::Apache::Actions;
use base 'Apache::Action';
__PACKAGE__->register('AppName', 'ObjectName',
action0 => \&handler0,
action1 => \&handler1,
...
);
sub handler0 {
my ($self) = @_;
# my $user = $self->state->user; # If user defined.
}
DESCRIPTION
This module reads values out of the HTTP submission and dispatches to
code as appropriate. The architecture requires four elements:
The apache request
This is normally a singleton instance of Apache::Request.
The persistent session
This is usually an Apache::Session, but anything which provides a
hashref will do. The session stores the persistent data, and may be
serialised by any method desired.
A request state
This is usually a subclass of Apache::Action::State and stores
nonserialisable and per-request data.
An action dispatcher.
This is an Apache::Action instance.
It is normal to write a class which inherits Apache::Action::State,
which generates and caches nonserialisable or non-normalised data on
demand. Things like user id may be stored in the session, and the state
may then provide a 'user' method which reads the user-id from the
session and retrieves the user from the database, caching the object for
the duration of the request. See eg/State.pm in this distribution for an
example.
Loaded modules may register actions with Apache::Action using the
'register' call, as described above. When an Apache::Action is 'run', it
looks for the field 'action' in the HTTP request parameters. This field
is of the form "application/module/action". It will then call the
appropriate subref, passing itself as the one and only parameter.
When using this module with HTML::Mason, it is normal to exoprt the
state and the session into the HTML::Mason::Commands namespace so that
they can be accessed by pages.
METHODS
Apache::Action->register($app, $module, $action)
Register a new action with Apache::Action. This is a class method
and is designed to be called from the top level of any loaded Perl
module. See eg/Feedback.pm for an example.
Apache::Action->new(...)
Construct a new Action object. This reqires three parameters:
Request, Session and State. The Request is an Apache::Request
instance. The Session is usually an Apache::Session instance but may
be any session hash. The State is an instance of
Apache::Action::State;
$action->run()
Search the HTTP arguments in the Request, and run an action, if
appropriate.
$action->param($name)
Return the HTTP parameter named.
$action->params($name)
Return a hashref of all HTTP parameters, copying the data.
$action->upload
Return an Apache::Upload object as named.
$action->session($name)
Return data from the session hash, as named.
$action->session($name, $value)
Store data in the session hash, as named.
$action->error($error)
Record that an error happened during this execution. The action
object will add the errors to the state object at the end of the
run. It is the responsibility of the Apache handler writer to check
whether any errors were recorded in the action object before
continuing. This method merely provides a log.
$action->errors()
Return a list of errors recorded in this execution.
BUGS
Mostly documentation. This code has been pulled out of a running system
and patched up for CPAN, so patches welcome if it doesn't run as
smoothly as expected outside of that system.
This module is quite hard to test outside Apache.
SUPPORT
Mail the author at <
[email protected]>
AUTHOR
Shevek
CPAN ID: SHEVEK
[email protected]
http://www.anarres.org/projects/
COPYRIGHT
Copyright (c) 2004 Shevek. All rights reserved.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
Apache::Action::State Apache::Session HTML::Mason