package Web::Dispatch;
use Sub::Quote;
use Scalar::Util qw(blessed);
sub MAGIC_MIDDLEWARE_KEY { __PACKAGE__.'.middleware' }
use Moo;
use Web::Dispatch::Parser;
use Web::Dispatch::Node;
with 'Web::Dispatch::ToApp';
has app => (is => 'ro', required => 1);
has parser_class => (
is => 'ro', default => quote_sub q{ 'Web::Dispatch::Parser' }
);
has node_class => (
is => 'ro', default => quote_sub q{ 'Web::Dispatch::Node' }
);
has node_args => (is => 'ro', default => quote_sub q{ {} });
has _parser => (is => 'lazy');
sub _build__parser {
my ($self) = @_;
$self->parser_class->new;
}
sub call {
my ($self, $env) = @_;
my $res = $self->_dispatch($env, $self->app);
return $res->[0] if ref($res) eq 'ARRAY' and @{$res} == 1 and ref($res->[0]) eq 'CODE';
return $res;
}
sub _dispatch {
my ($self, $env, @match) = @_;
while (defined(my $try = shift @match)) {
return $try if ref($try) eq 'ARRAY';
if (ref($try) eq 'HASH') {
$env = { 'Web::Dispatch.original_env' => $env, %$env, %$try };
next;
}
my @result = $self->_to_try($try, \@match)->($env, @match);
next unless @result and defined($result[0]);
my $first = $result[0];
if (my $res = $self->_have_result($first, \@result, \@match, $env)) {
return $res;
}
# make a copy so we don't screw with it assigning further up
my $env = $env;
unshift @match, sub { $self->_dispatch($env, @result) };
}
return;
}
sub _have_result {
my ($self, $first, $result, $match, $env) = @_;
if (ref($first) eq 'ARRAY') {
return $first;
}
elsif (blessed($first) && $first->isa('Plack::Middleware')) {
return $self->_uplevel_middleware($first, $result);
}
elsif (ref($first) eq 'HASH' and $first->{+MAGIC_MIDDLEWARE_KEY}) {
return $self->_redispatch_with_middleware($first, $match, $env);
}
elsif (
blessed($first) &&
not($first->can('to_app')) &&
not($first->isa('Web::Dispatch::Matcher'))
) {
return $first;
}
return;
}
sub _uplevel_middleware {
my ($self, $match, $results) = @_;
die "Multiple results but first one is a middleware ($match)"
if @{$results} > 1;
# middleware needs to uplevel exactly once to wrap the rest of the
# level it was created for - next elsif unwraps it
return { MAGIC_MIDDLEWARE_KEY, $match };
}
sub _redispatch_with_middleware {
my ($self, $first, $match, $env) = @_;
my $mw = $first->{+MAGIC_MIDDLEWARE_KEY};
$mw->app(sub { $self->_dispatch($_[0], @{$match}) });
return $mw->to_app->($env);
}
sub _to_try {
my ($self, $try, $more) = @_;
# sub (<spec>) {} becomes a dispatcher
# sub {} is a PSGI app and can be returned as is
# '<spec>' => sub {} becomes a dispatcher
# $obj isa WD:Predicates::Matcher => sub { ... } - become a dispatcher
# $obj w/to_app method is a Plack::App-like thing - call it to get a PSGI app
#
if (ref($try) eq 'CODE') {
if (defined(my $proto = prototype($try))) {
$self->_construct_node(match => $proto, run => $try)->to_app;
} else {
$try
}
} elsif (!ref($try) and ref($more->[0]) eq 'CODE') {
$self->_construct_node(match => $try, run => shift(@$more))->to_app;
} elsif (
(blessed($try) && $try->isa('Web::Dispatch::Matcher'))
and (ref($more->[0]) eq 'CODE')
) {
$self->node_class->new({
%{$self->node_args},
match => $try,
run => shift(@$more)
})->to_app;
} elsif (blessed($try) && $try->can('to_app')) {
$try->to_app;
} else {
die "No idea how we got here with $try";
}
}
sub _construct_node {
my ($self, %args) = @_;
$args{match} = $self->_parser->parse($args{match});
$self->node_class->new({ %{$self->node_args}, %args });
}
1;