GraphQL::Plugin::Type - GraphQL plugins implementing types

       Class implementing the scheme by which additional GraphQL type classes can be implemented.

       The author considers this is only worth doing for scalars, and indeed this scheme is (now) how the non-
       standard "DateTime" is implemented in graphql-perl. If one wants to create other types
       (GraphQL::Type::Object, GraphQL::Type::InputObject, etc), then the Schema Definition Language is already
       available. However, any type can be registered with the "register" method, and will be automatically
       available to GraphQL::Schema objects with no additional code.

register($graphql_type)
       When called with a GraphQL::Type subclass, will register it, otherwise dies.

   registered
       Returns a list of registered classes.

perl v5.34.0                                       2022-03-27                         GraphQL::Plugin::Type(3pm)

       GraphQL::Plugin::Type - GraphQL plugins implementing types

         package GraphQL::Plugin::Type::DateTime;
         use Moo;
         extends qw(GraphQL::Plugin::Type);
         my $iso8601 = DateTime::Format::ISO8601->new;
         GraphQL::Plugin::Type->register(
           GraphQL::Type::Scalar->new(
             name => 'DateTime',
             serialize => sub { return if !defined $_[0]; $_[0].'' },
             parse_value => sub { return if !defined $_[0]; $iso8601->parse_datetime(@_); },
           )
         );
         1;

         package main;
         use GraphQL::Schema;
         use GraphQL::Plugin::Type::DateTime;
         use GraphQL::Execution qw(execute);
         my $schema = GraphQL::Schema->from_doc(<<'EOF');
         type Query { dateTimeNow: DateTime }
         EOF
         post '/graphql' => sub {
           send_as JSON => execute(
             $schema,
             body_parameters->{query},
             { dateTimeNow => sub { DateTime->now } },
             undef,
             body_parameters->{variables},
             body_parameters->{operationName},
             undef,
           );
         };