Class::Hook - Add hooks on methods from other classes
use Class::Hook; Class::Hook->before(\&sub1); Class::Hook->after(\&sub2); Class::Hook->activate(); # or Class::Hook->new(\&sub1, \&sub2); # and then Anotherclass->aMethod($someParam); # Hooked class
Class::Hook enables you to trace methods calls from your code to other classes.
Instead of putting 'use Foo;' in your code, simply type 'use Class::Hook;'. The class Foo is unknown in your code. It will be magically catched by Class::Hook which will call Foo itself. You can see Class::Hook as a kind of relay.
You can setup a subroutine to be called before any call to Foo->amethod and a subroutine to be called after the call. Your subs will receive all the information that Foo->amethod will receive, so you can trace everything between your code and Foo.
Install subroutines to be called whenever a method from an unknown class is called. It is equivalent to the following code:
Class::Hook->before($subref_before, $param); Class::Hook->after($subref_after, $param); Class::Hook->activate();
Install subroutine to be called whenever a call to an unknown class is made. $param will be sent to your $subref if specified &$subref will receive the following parameters:
( $param, { class => $class_or_object, method => $method_called, param => [@params_sent], counter => $no_calls_for_this_method } ) or the following parameters if $param undefined ({ class => $class_or_object, method => $method_called, param => [@params_sent], counter => $no_calls_for_this_method } )
Install subroutine to be called whenever a call to an unknown class returns. $param will be sent to your $subref if specified. &$subref will receive the following parameters
( $param, { class => $class_or_object, method => $method_called, param => [@params_sent], counter => $no_calls_for_this_method, 'return' => [@return_values], duration => $duration in seconds } ) or the following parameters if $param undefined ( { class => $class_or_object, method => $method_called, param => [@params_sent], counter => $no_calls_for_this_method, 'return' => [@return_values], duration => $duration in seconds } )
Activates the hooks on methods calls to unknown classes. Your subs before and after will be called at each call to an unknown package.
before
after
Stops hooks.
You want to study calls to a class 'Foo' ======================================== main.pl ======= # Don't write 'use Foo;'! use Data::Dumper; use Class::Hook; Class::Hook->new(\&mybefore, \&myafter); Foo->new('bla', 'blu'); Foo->bar( { key1 => 'value1', key2 => 'value2'} ); Foo->xxxx(); # Non existing method sub mybefore { print "Before called: ".Dumper(\@_); } sub myafter { print "After called: ".Dumper(\@_); } Foo.pm ====== package Foo; sub new { my ($class, @param) = @_; warn "Foo->new called"; return bless { 'something' => 'whatever', 'init' => \@param } => $class; } sub bar { warn "Foo->bar called"; return "Hello from bar"; } 1;
It works only with method calls, not with subroutines calls. Foo->method will work Foo::method will NOT work UNIVSERAL::AUTOLOAD is overriden after Class::Hook->activate() has been called. Expect some strange behaviors if the module you use plays with it.
Don't rely on it for production purpose. Has been tested on perl 5.6.0 only and probably will need some update with later perl versions.
"Pierre Denis" <pierre@itrelease.net>
Copyright (C) 2005, IT Release Ltd. All rights reserved.
This is free software. This software may be modified and/or distributed under the same terms as Perl itself.
To install Class::Hook, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Class::Hook
CPAN shell
perl -MCPAN -e shell install Class::Hook
For more information on module installation, please visit the detailed CPAN module installation guide.