package MooseX::UndefTolerant::Constructor;
+
+# applied to constructor method metaclass, for Moose < 1.9900
+
use Moose::Role;
-around('_generate_slot_initializer', sub {
- my $orig = shift;
- my $self = shift;
- my $attr = $self->_attributes->[$_[0]]->init_arg;
+use strict;
+use warnings;
- my $tolerant_code =
- qq# delete \$params->{'$attr'} unless # .
- qq# exists \$params->{'$attr'} && defined \$params->{'$attr'};\n#;
+around _generate_slot_initializer => sub {
+ my $orig = shift;
+ my $self = shift;
- return $tolerant_code . $self->$orig(@_);
-});
+ # note the key in the params may not match the attr name.
+ my $key_name = $self->_attributes->[$_[0]]->init_arg;
-no Moose::Role;
+ # insert a line of code at the start of the initializer,
+ # clearing the param if it's undefined.
+
+ if (defined $key_name)
+ {
+ # leave the value unscathed if the attribute's type constraint can
+ # handle undef (or doesn't have one, which implicitly means it can)
+ my $type_constraint = $self->_attributes->[$_[0]]->type_constraint;
+ if ($type_constraint and not $type_constraint->check(undef))
+ {
+ my $tolerant_code =
+ qq# delete \$params->{'$key_name'} unless # .
+ qq# exists \$params->{'$key_name'} && defined \$params->{'$key_name'};\n#;
+ return $tolerant_code . $self->$orig(@_);
+ }
+ }
+
+ return $self->$orig(@_);
+};
+
+no Moose::Role;
1;