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Re: Right place to put common execute code in App::Cmd

by tobyink (Abbot)
on Dec 10, 2012 at 14:59 UTC ( #1008110=note: print w/ replies, xml ) Need Help??


in reply to Right place to put common execute code in App::Cmd

This is the kind of place where aspect-oriented programming is awesome. If you're using Moose, Moo or another OO library that supports method modifiers, then it's probably just a matter of creating a role with a before execute method modifier and then applying it to all your command classes.

Otherwise, if you have a base class for all your command classes, you could try creating a method called before_execute and then manually modifying all your execute methods to call $_[0]->before_execute at the start.

perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'


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Re^2: Right place to put common execute code in App::Cmd
by McA (Curate) on Dec 10, 2012 at 15:06 UTC

    Hi tobyink,

    thank you for answering that fast. I have to admit that I hoped it. ;-) (a ++ for that)

    The first suggestion is not an option for me right now. The second approach is which I'm doing right now. But I wanted to avoid the call of before_execute in every execute method. I really hoped that there is another callback which I haven't found.

    Once again. Thank you.

    Best regards
    McA

      "I really hoped that there is another callback which I haven't found."

      The relevant code is App::Cmd::execute_command. As you can see, nothing happens between validate_args and execute that you could possibly hook onto.

      One alternative approach could be to subclass App::Cmd, overriding that method with your own implementation that adds extra hooks between validate_args and execute:

      { package My::App::Cmd; use base 'App::Cmd'; sub execute_command { my ($self, $cmd, $opt, @args) = @_; local our $active_cmd = $cmd; $cmd->validate_args($opt, \@args); $cmd->before_execute($opt, \@args); $cmd->execute($opt, \@args); } }

      Then use My::App::Cmd instead of App::Cmd.

      perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

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