NAME
Hook::AfterRuntime - Run code at the end of the compiling scope's
runtime.
DESCRIPTION
Useful for creating modules that need a behavior to be added when a
module that uses them completes its runtime. Like B::Hooks::EndOfScope
except it triggers for run-time instead of compile-time.
Example where it might be handy:
#!/usr/bin/perl
use strict;
use warnings;
use Moose;
...
# It would be nice not to need this....
__PACKAGE__->make_immutable;
SYNOPSYS
MooseX/AutoImmute.pm
package MooseX::AutoImmute;
use strict;
use warnings;
use Hook::AfterRuntime;
sub import {
my $class = shift;
my $caller = caller;
eval "package $caller; use Moose; 1" || die $@;
after_runtime { $caller->make_immutable }
}
1;
t/mytest.t
#!/usr/bin/perl
use strict;
use warnings;
use MooseX::AutoImmute;
....
#EOF
# Package is now immutable autamatically
CAVEATS
It is important to understand how Hook::AfterRuntime works n order to
know its limitations. When you use a module that calls after_runtime()
in its import() method, after_runtime() will inject code directly after
your import statement:
import MooseX::AutoImmute;
becomes:
import MooseX::AutoImmute; my $__ENDRUNXXXXXXXX = Hook::AfterRuntime->new($id);
This creates a Hook::AfterRuntime object in the corrunt scope. This
object's id is used to reference the code provided to after_runtime() in
MooseX::AutoImmute()'s import() method. When the object falls out of
scope the DESTROY() method kicks in and calls the referenced code. This
occurs at the end of the file when 'use' is called at the package level.
EDGE CASES
Loading in a scope other than package level:
If you use the 'use' directive on a level other than the package
level, the behavior will trigger when the end of the scope is
reached. If that is a subroutine than it will trigger at the end of
EVERY call to that subroutine. You really should not import a class
using Hook::AfterRuntime outside tha package level scope.
package XXX;
sub thing {
# Happens at compile time
use Object::Using::AfterRuntime;
# At run time the hook behavior triggers here!
}
# hook behavior has not triggered
thing()
# Hook behavior has triggered
1;
require, and use class ();
When require and use class () are used the import method is not called,
thus the hook is never installed.
class->import
The hook effects the code that is currently compiling. calling
class->import happens after the compilation phase. You must wrap the
statement in a BEGIN {} to call import manually. Failure to do this will
result in the hook triggering in the wrong class, or not at all.
USER WARNING
When you write a class that depends on this hook you should insert the
following warning into the docs:
This class uses Hook::AfterRuntime, it MUST be imported at the package
level at compile time. This means 'use MODULE' or 'BEGIN { require
MODULE; MODULE->import() }'. Failure to use one of these correct forms
will result in a missing hook and unpredictable behavior.
SEE ALSO
B::Hooks::EndOfScope
Does almost the same thing, except it is triggered after
compile-time instead of run-time.
FENNEC PROJECT
This module is part of the Fennec project. See Fennec for more details.
Fennec is a project to develop an extendable and powerful testing
framework. Together the tools that make up the Fennec framework provide
a potent testing environment.
The tools provided by Fennec are also useful on their own. Sometimes a
tool created for Fennec is useful outside the greator framework. Such
tools are turned into their own projects. This is one such project.
Fennec - The core framework
The primary Fennec project that ties them all together.
AUTHORS
Chad Granum [email protected]
COPYRIGHT
Copyright (C) 2010 Chad Granum
Hook-AfterRuntime is free software; Standard perl licence.
Hook-AfterRuntime is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the license for
more details.