[dfv] Data::FormValidator::Constraints::Upload

[Jiří P. <ji...@ge...>]

Hello,

I want to use Data::FormValidator::Constraints::Upload to validate photo 
upload. I want to check the image type and optionally (based on other 
parameter) its dimensions).
I'm not quite sure what is the best way to handle the optional 
conditional constraint.
What I did was to store the constraint subroutines returned by the 
appropriate methods in a variable and wrote my own constrain methods.
I'm just not sure whether it is the best approach.

Here is what I have:

   my $image_type_constraint = file_format(mime_types => ['image/png'] );
   my $image_size_constraint = image_max_dimensions(200,200);

...

  constraint_methods => {
         photo_file  => {
             constraint_method  => sub {
                 my ( $dfv, $photo_file, $main_web_photo,) = @_;
                 return 0 unless $image_type_constraint->($dfv, 
$photo_file);

                 if ($main_web_photo) {
                     return 0 unless $image_size_constraint->($dfv, 
$photo_file);
                 }

                 return 1;

             },
             params         => [ qw( photo_file main_web_photo ) ],
         },
     },