Crypt::OpenPGP::ErrorHandler - Crypt::OpenPGP error handling
package Foo; use Crypt::OpenPGP::ErrorHandler; use base qw( Crypt::OpenPGP::ErrorHandler );
sub class_method { my $class = shift; ... return $class->error("Help!") unless $continue; }
sub object_method { my $obj = shift; ... return $obj->error("I am no more") unless $continue; }
package main; use Foo;
Foo->class_method or die Foo->errstr;
my $foo = Foo->new; $foo->object_method or die $foo->errstr;
Crypt::OpenPGP::ErrorHandler provides an error-handling mechanism for all Crypt::OpenPGP modules/classes. It is meant to be used as a base class for classes that wish to use its error-handling methods: derived classes use its two methods, error and errstr, to communicate error messages back to the calling program.
On failure (for whatever reason), a subclass should call error
and return to the caller; error itself sets the error message
internally, then returns undef
. This has the effect of the method
that failed returning undef
to the caller. The caller should
check for errors by checking for a return value of undef
, and
in this case should call errstr to get the value of the error
message. Note that calling errstr when an error has not occurred
is undefined behavior and will rarely do what you want.
As demonstrated in the SYNOPSIS (above), error and errstr work both as class methods and as object methods.
Sets the error message for either the class Class or the object
$object to the message $message. Returns undef
.
Accesses the last error message set in the class Class or the object $object, respectively, and returns that error message.
Please see the Crypt::OpenPGP manpage for author, copyright, and license information.