improved error-handling

[akarelas]

Before, if an error occurred during the authorization stage, the user would just keep on visiting the oauth2 provider in an endless loop. With this patch, at least in blocking mode, get_token will return ($token, $err, $state) and the user won't enter an endless loop. The programmer can now easily check $err.

If it didn't break backwards compatibility, I would have implemented something similar for the non-blocking mode.

[akarelas]

I made $err to be a hashref, so that it can be expanded in the future with extra fields if needed without breaking backwards compatibility.

[akarelas]

This fix can turn this complex-looking blocking route handler:

my $token = eval { $self->get_token('facebook', on_refuse => sub { die \'refused'; }); };
if (my $e = $@) {
    if (ref $e eq 'SCALAR' and $$e eq 'refused') {
        return $self->render(text => 'refused');
    } else {
        die $e;
    }
}
if ($token) {
    # ...
}

...into this:

my ($token, $err) = $self->get_token('facebook');
if ($err and $err->{error} eq 'access_denied') {
    return $self->render(text => 'refused');
}
if ($token) {
    # ...
}

[akarelas]

Of course needs documentation and tests. Will do these if you tell me you want this pull request.

[akarelas]

Pinging for attention from Marcus.

[marcusramberg]

Ok, been going a bit back and forth on this one, but I think it's an improvement, so I'll accept it if you provide tests and documentation.

[akarelas]

Will do the tests & documentation for this pull request, in a few days.

[jhthorsen]

This is fixed in master.

See these commits:
acb0599
7527fd0
6fff3c6