Re: Better handling of constraint failures?

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On Thu, 12 Aug 2004, Clayton L. Scott wrote:

> On Thu, 12 Aug 2004, Drew Taylor wrote:
>
> > Clayton L. Scott wrote:
>
> > > #Film->constrain_column(year => qr/\d{4}/);
> > > Film->constrain_column(year => [ 'Year must be four digits' => qr/\d{4}/]);
> >
> > Hmmm, I somehow overlooked this method. I've always just used
> > add_constraint(). I do think having a nice error message to report back
> > to the user is a good thing. The problem with the syntax you propose
> > above is that constrain_column() currently takes a regex or arrayref of
> > valid values. Seems like the code would be ugly to check if the 2nd
> > valid value is a regex.
>
> What I'm prosing here is a new, backwards incompatible syntax for
> constrain_column that allows you to:
>
> + add multiple constraints in one call
> + specify a verbose message upon failure
> + specify the constraint as REGEXP, CODE or ARRAY

Actually I'd change the syntax to be

Film->constrain_column(year => {'Year must be four digits'
                                  => qr/\d{4}/,
                                'Year cannot be before 1960'
                                  => sub { shift < 1960 ? 0 : 1 },
                                }
                      );


Clayton