Initial Commit

database/perl/vendor/lib/Crypt/OpenPGP/ErrorHandler.pm

@@ -0,0 +1,92 @@
+package Crypt::OpenPGP::ErrorHandler;
+use strict;
+
+use vars qw( $ERROR );
+
+sub new    { bless {}, shift }
+sub error  {
+    my $msg = $_[1];
+    $msg .= "\n" unless $msg =~ /\n$/;
+    if (ref($_[0])) {
+        $_[0]->{_errstr} = $msg;
+    } else {
+        $ERROR = $msg;
+    }
+    return;
+ }
+sub errstr { ref($_[0]) ? $_[0]->{_errstr} : $ERROR }
+
+1;
+__END__
+
+=head1 NAME
+
+Crypt::OpenPGP::ErrorHandler - Crypt::OpenPGP error handling
+
+=head1 SYNOPSIS
+
+    package Foo;
+    use Crypt::OpenPGP::ErrorHandler;
+    use base qw( Crypt::OpenPGP::ErrorHandler );
+
+    sub class_method {
+        my $class = shift;
+        # Stuff happens...
+        return $class->error("Help!");
+    }
+
+    sub object_method {
+        my $obj = shift;
+        # Stuff happens...
+        return $obj->error("I am no more");
+    }
+
+    package main;
+
+    Foo->class_method or die Foo->errstr;
+
+    my $foo = Foo->new;
+    $foo->object_method or die $foo->errstr;
+
+=head1 DESCRIPTION
+
+I<Crypt::OpenPGP::ErrorHandler> provides an error-handling mechanism
+for all I<Crypt::OpenPGP> modules/classes. It is meant to be used as
+a base class for classes that wish to use its error-handling methods:
+derived classes use its two methods, I<error> and I<errstr>, to
+communicate error messages back to the calling program.
+
+On failure (for whatever reason), a subclass should call I<error>
+and return to the caller; I<error> itself sets the error message
+internally, then returns C<undef>. This has the effect of the method
+that failed returning C<undef> to the caller. The caller should
+check for errors by checking for a return value of C<undef>, and
+in this case should call I<errstr> to get the value of the error
+message. Note that calling I<errstr> when an error has not occurred
+is undefined behavior and will I<rarely> do what you want.
+
+As demonstrated in the I<SYNOPSIS> (above), I<error> and I<errstr> work
+both as class methods and as object methods.
+
+=head1 USAGE
+
+=head2 Class->error($message)
+
+=head2 $object->error($message)
+
+Sets the error message for either the class I<Class> or the object
+I<$object> to the message I<$message>. Returns C<undef>.
+
+=head2 Class->errstr
+
+=head2 $object->errstr
+
+Accesses the last error message set in the class I<Class> or the
+object I<$object>, respectively, and returns that error message.
+
+=head1 AUTHOR & COPYRIGHTS
+
+Please see the Crypt::OpenPGP manpage for author, copyright, and
+license information.
+
+=cut