Adam Kennedy > Aspect-1.04 > Aspect::Advice::Around

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Module Version: 1.04   Source  

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 . "\n";
  
      # 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 - 2013 Adam Kennedy.

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

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