NAME
Params::CallbackRequest::Exceptions - Parameter callback exception definitions
SYNOPSIS
use Params::CallbackRequest::Exceptions;
Params::Callback::Exception::Execution->throw("Whoops!");
use Params::CallbackRequest::Exceptions abbr => [qw(throw_cb_exec)];
throw_cb_exec "Whoops!";DESCRIPTION
This module creates the exceptions used by Params::CallbackRequest and Params::Callback. The exceptions are subclasses of Exception::Class::Base, created by the interface defined by Exception::Class.
INTERFACE
Exported Functions
This module exports two functions by default.
isa_cb_exception
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.";
}
}This function takes a single argument and returns true if it's a Params::Callback::Exception object. A second, optional argument can be used to identify a particular subclass of Params::Callback::Exception.
rethrow_exception
eval { something_that_dies() };
if (my $err = $@) {
# Do something intelligent, and then...
rethrow_exception($err);
}This function takes an exception as its sole argument and rethrows it. If the argument is an object that can('throw'), such as any subclass of Exception::Class, then rethrow_exception() will call its rethrow method. If not, but the argument is a reference, rethrow_exception() will simply die with it. And finally, if the argument is not a reference at all, rethrow_exception() will throw a new Params::Callback::Exception exception with the argument used as the exception error message.
Abbreviated Exception Functions
Each of the exception classes created by Params::CallbackRequest::Exceptions has a functional alias for its throw class method. These may be imported by passing an array reference of the names of the abbreviated functions to import via the abbr parameter:
use Params::CallbackRequest::Exceptions abbr => [qw(throw_cb_exec)];The names of the abbreviated functions are:
- 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
Exception Classes
The exception classes created by Params::Callback::Exception are as follows:
Params::Callback::Exception
This is the base class for all Params::Callback exception classes. Its functional alias is throw_cb.
Params::Callback::Exception::InvalidKey
Params::CallbackRequest throws this exception when a callback key in the parameter hash passed to new() has no corresponding callback. In addition to the attributes offered by Exception::Class::Base, this class also features the attribute callback_key. Use the callback_key() accessor to see what callback key triggered the exception. 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. In addition to the attributes offered by Exception::Class::Base, this class also features the attributes callback_key, which corresponds to the parameter key that triggered the callback, and callback_error which is the error thrown by the callback subroutine or method. Params::Callback::Exception::Execution's functional alias is throw_cb_exec.
Params::Callback::Exception::Params
This is the exception thrown when an invalid parameter is passed to Params::CallbackRequest's or Params::Callback's new() constructors. Its functional alias is throw_bad_params.
Params::Callback::Exception::Abort
This is the exception thrown by Params::Callback's abort() method. functional alias is throw_cb. In addition to the attributes offered by Exception::Class::Base, this class also features the attribute aborted_value attribute. Use the aborted_value() accessor to see what value was passed to abort(). Params::Callback::Exception::Abort's functional alias is throw_abort.
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.
AUTHOR
David Wheeler <david@kineticode.com>
COPYRIGHT AND LICENSE
Copyright 2003 by David Wheeler
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.