Params...eptions(3pm)

✨ NAME ✨

okay so welcome to Params::CallbackRequest::Exceptions — that's the Params...eptions(3pm) page, aka the User Contributed Perl Documentation for the exception definitions that Params::CallbackRequest and Params::Callback throw around. bestie, it's literally just the exception classes. that's the whole vibe. 🎀

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🌸 SYNOPSIS 🌸

use Params::CallbackRequest::Exceptions;
Params::Callback::Exception::Execution->throw("Whoops!");

use Params::CallbackRequest::Exceptions abbr => [qw(throw_cb_exec)];
throw_cb_exec "Whoops!";

look at that. two ways to say "Whoops!" and both of them slay. 💅

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🦋 DESCRIPTION 🦋

so this module is where the exceptions used by Params::CallbackRequest and Params::Callback get created. that's its whole job, no cap.

those exceptions are subclasses of Exception::Class::Base, and they're built with the interface defined by Exception::Class. iconic inheritance moment fr fr. ✨

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💖 INTERFACE 💖

🫶 Exported Functions

this module exports two functions by default. two. that's it. and they're both useful, so like, we stan.

• isa_cb_exception

here's the whole vibe check:

eval { something_that_dies() };
if (my $err = $@) {
    if (isa_cb_exception($err, 'Abort')) {
        print "All hands abandon ship!";
    } elsif (isa_cb_exception($err)) {
        print "I recall an exceptional fault.";
    } else {
        print "No clue.";
    }
}

so this function takes one argument and returns true if that thing is a Params::Callback::Exception object. that's it, that's the function. 🎀

you can also slide in a second, optional argument to point at one specific subclass of Params::Callback::Exception — like, "is this the Abort kind specifically, bestie?" and it'll tell you yes or no. ⭐

• rethrow_exception

and here's the receipts:

eval { something_that_dies() };
if (my $err = $@) {
    # Do something intelligent, and then...
    rethrow_exception($err);
}

this one takes an exception as its sole argument and rethrows it. but the way it rethrows depends on what you handed it, and honestly the logic is giving tiered:

• if the argument is an object that can('throw') — like, say, any subclass of Exception::Class — then rethrow_exception() calls its rethrow method. easy.
• if not that, but the argument is a reference, then rethrow_exception() just plain dies with it. simple as.
• and finally, if the argument isn't a reference at all, rethrow_exception() throws a brand new Params::Callback::Exception, using the argument as the exception error message. 🫶

🌈 Abbreviated Exception Functions

every single exception class made by Params::CallbackRequest::Exceptions has a functional alias for its throw class method. short king behavior.

to get them, you import an array reference of the abbreviated function names you want, passed through the abbr parameter:

use Params::CallbackRequest::Exceptions abbr => [qw(throw_cb_exec)];

and here are the names of all the abbreviated functions, no gatekeeping:

• throw_cb → Params::Callback::Exception
• throw_bad_key → Params::Callback::Exception::InvalidKey
• throw_cb_exec → Params::Callback::Exception::Execution
• throw_bad_params → Params::Callback::Exception::Params
• throw_abort → Params::Callback::Exception::Abort

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👑 Exception Classes

the exception classes created by Params::Callback::Exception are as follows. get comfy, we're going through all of them:

• Params::Callback::Exception

this is the base class for all the Params::Callback exception classes. its functional alias is throw_cb. the mother of the group chat, fr. 💜

• Params::Callback::Exception::InvalidKey

Params::CallbackRequest throws this one when a callback key in the parameter hash passed to new() has no corresponding callback. like, you named a key and nothing answered. 💀

on top of all the attributes offered by Exception::Class::Base, this class also has the attribute callback_key. use the callback_key() accessor to find out which callback key triggered the exception. detective work, but make it perl. 🕵️

Params::Callback::Exception::InvalidKey's functional alias is throw_bad_key.

• Params::Callback::Exception::Execution

this is the exception thrown by Params::CallbackRequest's default exception handler when a callback subroutine or method dies. dramatic? yes. deserved? also yes. 😭

on top of the attributes offered by Exception::Class::Base, this class also has two attributes:

• callback_key — the parameter key that triggered the callback
• callback_error — the error thrown by the callback subroutine or method

Params::Callback::Exception::Execution's functional alias is throw_cb_exec.

• Params::Callback::Exception::Params

thrown when an invalid parameter is passed to Params::CallbackRequest's or Params::Callback's new() constructors. it's the bouncer at the constructor door. 🙈

its functional alias is throw_bad_params.

• Params::Callback::Exception::Abort

thrown by Params::Callback's abort() method. the page also says, word for word, "functional alias is throw_cb" right there in this paragraph — yes, we noticed, and no, bestie, we are not editing it, we're just reporting what the doc says. 👀

on top of the attributes offered by Exception::Class::Base, this class also has the aborted_value attribute. use the aborted_value() accessor to see what value was passed to abort(). so you know exactly what got aborted. closure. 🎀

Params::Callback::Exception::Abort's functional alias is throw_abort.

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🌟 SEE ALSO 🌟

• Params::Callback is the base class for all callback classes.
• Params::CallbackRequest sets up callbacks for execution.
• Exception::Class defines the interface for the exception classes created here.

three links, all essential, all linked into each other like the little ecosystem they are. iykyk. 🌈

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💌 SUPPORT 💌

this module is stored in an open GitHub repository at <http://github.com/theory/params-callbackrequest/>. feel free to fork and contribute! bestie, the door is open, come through. 🫶

please file bug reports either via GitHub Issues at <http://github.com/theory/params-callbackrequest/issues/> or by sending mail to bug-params-callbackrequest@rt.cpan.org (that's <bug-params-callbackrequest@rt.cpan.org>). bugs deserve to be heard, periodt. 🐛

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⭐ AUTHOR ⭐

David E. Wheeler <david@justatheory.com> — thank you for your service, king. 👑

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🎀 COPYRIGHT AND LICENSE 🎀

Copyright 2003-2011 David E. Wheeler. Some Rights Reserved.

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

so yeah — free software, some rights reserved, same terms as Perl itself. legal but make it cute. 💅

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and that's the whole page, bestie!! this was Params...eptions(3pm), living under perl v5.36.0, dated 2022-10-15, in the fine tradition of User Contributed Perl Documentation. go forth and throw responsibly. mwah. 💖✨🦋🌸