add before_serializer

Taskfile.yaml

@@ -7,7 +7,7 @@ vars:
   TARGET_BRANCH: main
 
 tasks:
-  format:
+  pretty:
     cmds:
       - git diff-ls --diff-filter=ACMR {{.TARGET_BRANCH}} | grep -e '\.pm$\|\.t$' | xargs -IX perltidy -b X
     

lib/Dancer2/Plugin/JsonApi/Schema.pm

@@ -104,12 +104,18 @@ has attributes => (
     }
 );
 
+has before_serialize => ( is => 'ro' );
+
 sub serialize_data ( $self, $data, $extra_data = {}, $included = undef ) {
 
     return [ map { $self->serialize_data( $_, $extra_data, $included ) }
           @$data ]
       if ref $data eq 'ARRAY';
 
+    if ( $self->before_serialize ) {
+        $data = $self->before_serialize->( $data, $extra_data );
+    }
+
     # it's a scalar? it's the id
     return { id => $data, type => $self->type } unless ref $data;
 

t/schema.t

@@ -5,8 +5,7 @@ use Dancer2::Plugin::JsonApi::Registry;
 
 use experimental qw/ signatures /;
 
-my $type =
+my $type = Dancer2::Plugin::JsonApi::Schema->new( 'type' => 'thing' );
-  Dancer2::Plugin::JsonApi::Schema->new( 'type' => 'thing' );
 
 like $type->serialize( { attr1 => 'a', id => '123' }, { foo => 1 } ) => {
     jsonapi => { version => '1.0' },
@@ -35,8 +34,7 @@ is( $serialized->{data}{id} => '12',
 like $serialized->{data}, { links => { self => '/some/url' } }, "links";
 
 sub schema_serialize ( $schema, $data ) {
-    return Dancer2::Plugin::JsonApi::Schema->new(%$schema)
+    return Dancer2::Plugin::JsonApi::Schema->new(%$schema)->serialize($data);
-      ->serialize($data);
 }
 
 like(
@@ -133,4 +131,15 @@ subtest 'attributes function' => sub {
     is $serialized->{data}{attributes} => { 1 => 'id', b => 'a', d => 'c' };
 };
 
+subtest 'before_serializer' => sub {
+    my $serialized = Dancer2::Plugin::JsonApi::Schema->new(
+        type             => 'thing',
+        before_serialize => sub ( $data, @ ) {
+            return +{ %$data, nbr_attrs => scalar keys %$data };
+        },
+    )->serialize( { id => 1, a => 'b' } );
+
+    is $serialized->{data}{attributes}{nbr_attrs} => 2;
+};
+
 done_testing();