advice

Aspect::Advice::Around(3pm)				User Contributed Perl Documentation			       Aspect::Advice::Around(3pm)

NAME

       Aspect::Advice::Around - Execute code both before and after a function

SYNOPSIS

	 use Aspect;

	 around {
	     # Trace all calls to your module
	     print STDERR "Called my function " . $_->sub_name . "
";

	     # Lexically alter a global for this function
	     local $MyModule::MAXSIZE = 1000;

	     # Continue and execute the function
	     $_->run_original;

	     # Suppress exceptions for the call
	     $_->return_value(1) if $_->exception;

	 } call qr/^ MyModule::w+ $/;

DESCRIPTION

       The "around" advice type is used to execute code on either side of a function, allowing deep and precise control of how the function will
       be called when none of the other advice types are good enough.

       Using "around" advice is also critical if you want to lexically alter the environment in which the call will be made (as in the example
       above where a global variable is temporarily changed).

       This advice type is also the most computationally expensive to run, so if your problem can be solved with the use of a different advice
       type, particularly "before", you should use that instead.

       Please note that unlike the other advice types, your code in "around" is required to trigger the execution of the target function yourself
       with the "proceed" method. If you do not "proceed" and also do not set either a "return_value" or "exception", the function call will
       return "undef" in scalar context or the null list "()" in list context.

AUTHORS

       Adam Kennedy <adamk@cpan.org>

COPYRIGHT AND LICENSE

       Copyright 2010 Adam Kennedy.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-02-01					       Aspect::Advice::Around(3pm)