in reply to Re^2: Error Handling with Packages
in thread Error Handling with Packages

I have another custom approach:

sub new { my ($thing) = @_ ; my $class = ( ref($thing) or $thing ) ; my $self = bless({}, $class) ; $self->{'errMsg'} = ""; # module user can set this e.g. to sub { carp($_[0]->{'errMsg'}) } + or something: $self->{'errHandler'}; return $self ; } # Sets an error message, calls the error Handler, always returns undef sub raiseError { my ($self, $string) = @_; $self->{'errMsg'} = $string; &{$self->{'errHandler'}}($self) if $self->{'errHandler'}; return; } # returns error message and resets it to "" sub error { my ($self) = @_; my $msg = $self->{'errMsg'}; $self->{'errMsg'} = ""; return $msg; } # ... sub foo { my ($self) = @_; # do stuff if ($trouble) { return raiseError("foo: cannot do thisandthat"); } # no error: # make sure to return true-evaluating or at least non-undef value return 1; }

This way the module user can still use idioms like

$O->foo() or die "could not blabla: ".$O->error();

Users can still set the error handler to croak() if they wish. This could be extended ad nauseam: $debug switches, $exec_handler switch, method to get errMsg without resetting it -- you name it. I should probably put it in its own module, too, and inherit from that. I'm still not sure how to escalate errors when one method calls another. Maybe simply

sub bar { my ($self) = @_; foo() or return raiseError("bar failed to rhubarb: ".$self->error( +)); return 1; } # ... $O->bar() or die "could not blabla: ".$O->error(); # "could not blabla: bar failed to rhubarb: foo: could not do thisandt +hat"