package MooseX::Declare::Syntax::KeywordHandling;
use Moose::Role;
use Moose::Util::TypeConstraints;
use Devel::Declare ();
use Sub::Install qw( install_sub );
use Moose::Meta::Class ();
use aliased 'MooseX::Declare::Context';
use namespace::clean -except => 'meta';
requires qw(
parse
);
has identifier => (
is => 'ro',
isa => subtype(as 'Str', where { /^ [_a-z] [_a-z0-9]* $/ix }),
required => 1,
);
sub get_identifier { shift->identifier }
sub context_class { Context }
sub context_traits { }
sub setup_for {
my ($self, $setup_class, %args) = @_;
# make sure the stack is valid
my $stack = $args{stack} || [];
my $ident = $self->get_identifier;
# setup the D:D handler for our keyword
Devel::Declare->setup_for($setup_class, {
$ident => {
const => sub { $self->parse_declaration((caller(1))[1], \%args, @_) },
},
});
# search or generate a real export
my $export = $self->can('generate_export') ? $self->generate_export($setup_class) : sub { };
# export subroutine
install_sub({
code => $export,
into => $setup_class,
as => $ident,
}) unless $setup_class->can($ident);
return 1;
}
sub parse_declaration {
my ($self, $caller_file, $args, @ctx_args) = @_;
# find and load context object class
my $ctx_class = $self->context_class;
Class::MOP::load_class $ctx_class;
# do we have traits?
if (my @ctx_traits = $self->context_traits) {
Class::MOP::load_class $_
for @ctx_traits;
$ctx_class = Moose::Meta::Class->create_anon_class(
superclasses => [$ctx_class],
roles => [@ctx_traits],
cache => 1,
)->name;
}
# create a context object and initialize it
my $ctx = $ctx_class->new(
%{ $args },
caller_file => $caller_file,
);
$ctx->init(@ctx_args);
# parse with current context
return $self->parse($ctx);
}
1;
__END__
=head1 NAME
MooseX::Declare::Syntax::KeywordHandling - Basic keyword functionality
=head1 DESCRIPTION
This role provides the functionality common for all keyword handlers
in L<MooseX::Declare>.
=head1 ATTRIBUTES
=head2 identifier
This is the name of the actual keyword. It is a required string that is in
the same format as a usual Perl identifier.
=head1 REQUIRED METHODS
=head2 parse
Object->parse (Object $context)
This method must implement the actual parsing of the keyword syntax.
=head1 METHODS
=head2 get_identifier
Str Object->get_identifier ()
Returns the name the handler will be setup under.
=head2 setup_for
Object->setup_for (ClassName $class, %args)
This will setup the handler in the specified C<$class>. The handler will
dispatch to the L</parse_declaration> method when the keyword is used.
A normal code reference will also be exported into the calling namespace.
It will either be empty or, if a C<generate_export> method is provided,
the return value of that method.
=head2 parse_declaration
Object->parse_declaration (Str $filename, HashRef $setup_args, @call_args)
This simply creates a new L<context|MooseX::Declare::Context> and passes it
to the L</parse> method.
=head1 SEE ALSO
=over
=item * L<MooseX::Declare>
=item * L<MooseX::Declare::Context>
=back
=head1 AUTHOR, COPYRIGHT & LICENSE
See L<MooseX::Declare>
=cut