Documentation fix for Catalyst::Response::from_psgi_response

[catagits/Catalyst-Runtime.git] / lib / Catalyst / Response.pm

package Catalyst::Response;

use Moose;
use HTTP::Headers;
use Moose::Util::TypeConstraints;
use namespace::autoclean;

with 'MooseX::Emulate::Class::Accessor::Fast';

has _response_cb => (
    is      => 'ro',
    isa     => 'CodeRef',
    writer  => '_set_response_cb',
    clearer => '_clear_response_cb',
    predicate => '_has_response_cb',
);

subtype 'Catalyst::Engine::Types::Writer',
    as duck_type([qw(write close)]);

has _writer => (
    is      => 'ro',
    isa     => 'Catalyst::Engine::Types::Writer',
    writer  => '_set_writer',
    clearer => '_clear_writer',
    predicate => '_has_writer',
);

has write_fh => (
  is=>'ro',
  predicate=>'_has_write_fh',
  lazy=>1,
  builder=>'_build_write_fh',
);

sub _build_write_fh {
  my $self = shift;
  $self->_context->finalize_headers unless
    $self->finalized_headers;
  $self->_writer;
};

sub DEMOLISH {
  my $self = shift;
  return if $self->_has_write_fh;
  if($self->_has_writer) {
    $self->_writer->close
  }
}

has cookies   => (is => 'rw', default => sub { {} });
has body      => (is => 'rw', default => undef);
sub has_body { defined($_[0]->body) }

has location  => (is => 'rw');
has status    => (is => 'rw', default => 200);
has finalized_headers => (is => 'rw', default => 0);
has headers   => (
  is      => 'rw',
  isa => 'HTTP::Headers',
  handles => [qw(content_encoding content_length content_type header)],
  default => sub { HTTP::Headers->new() },
  required => 1,
  lazy => 1,
);
has _context => (
  is => 'rw',
  weak_ref => 1,
  clearer => '_clear_context',
);

sub output { shift->body(@_) }

sub code   { shift->status(@_) }

sub write {
    my ( $self, $buffer ) = @_;

    # Finalize headers if someone manually writes output
    $self->_context->finalize_headers unless $self->finalized_headers;

    $buffer = q[] unless defined $buffer;

    my $len = length($buffer);
    $self->_writer->write($buffer);

    return $len;
}

sub finalize_headers {
    my ($self) = @_;

    # This is a less-than-pretty hack to avoid breaking the old
    # Catalyst::Engine::PSGI. 5.9 Catalyst::Engine sets a response_cb and
    # expects us to pass headers to it here, whereas Catalyst::Enngine::PSGI
    # just pulls the headers out of $ctx->response in its run method and never
    # sets response_cb. So take the lack of a response_cb as a sign that we
    # don't need to set the headers.

    return unless $self->_has_response_cb;

    # If we already have a writer, we already did this, so don't do it again
    return if $self->_has_writer;

    my @headers;
    $self->headers->scan(sub { push @headers, @_ });

    my $writer = $self->_response_cb->([ $self->status, \@headers ]);
    $self->_set_writer($writer);
    $self->_clear_response_cb;

    return;
}

sub from_psgi_response {
    my ($self, $psgi_res) = @_;
    if(ref $psgi_res eq 'ARRAY') {
        my ($status, $headers, $body) = @$psgi_res;
        $self->status($status);
        $self->headers(HTTP::Headers->new(@$headers));
        if(ref $body eq 'ARRAY') {
          $self->body(join '', grep defined, @$body);
        } else {
          $self->body($body);
        }
    } elsif(ref $psgi_res eq 'CODE') {
        $psgi_res->(sub {
            my $response = shift;
            my ($status, $headers, $maybe_body) = @$response;
            $self->status($status);
            $self->headers(HTTP::Headers->new(@$headers));
            if($maybe_body) {
                if(ref $maybe_body eq 'ARRAY') {
                  $self->body(join '', grep defined, @$maybe_body);
                } else {
                  $self->body($maybe_body);
                }
            } else {
                return $self->write_fh;
            }
        });  
     } else {
        die "You can't set a Catalyst response from that, expect a valid PSGI response";
    }
}

=head1 NAME

Catalyst::Response - stores output responding to the current client request

=head1 SYNOPSIS

    $res = $c->response;
    $res->body;
    $res->code;
    $res->content_encoding;
    $res->content_length;
    $res->content_type;
    $res->cookies;
    $res->header;
    $res->headers;
    $res->output;
    $res->redirect;
    $res->status;
    $res->write;

=head1 DESCRIPTION

This is the Catalyst Response class, which provides methods for responding to
the current client request. The appropriate L<Catalyst::Engine> for your environment
will turn the Catalyst::Response into a HTTP Response and return it to the client.

=head1 METHODS

=head2 $res->body( $text | $fh | $iohandle_object )

    $c->response->body('Catalyst rocks!');

Sets or returns the output (text or binary data). If you are returning a large body,
you might want to use a L<IO::Handle> type of object (Something that implements the read method
in the same fashion), or a filehandle GLOB. Catalyst
will write it piece by piece into the response.

=head2 $res->has_body

Predicate which returns true when a body has been set.

=head2 $res->code

Alias for $res->status.

=head2 $res->content_encoding

Shortcut for $res->headers->content_encoding.

=head2 $res->content_length

Shortcut for $res->headers->content_length.

=head2 $res->content_type

Shortcut for $res->headers->content_type.

This value is typically set by your view or plugin. For example,
L<Catalyst::Plugin::Static::Simple> will guess the mime type based on the file
it found, while L<Catalyst::View::TT> defaults to C<text/html>.

=head2 $res->cookies

Returns a reference to a hash containing cookies to be set. The keys of the
hash are the cookies' names, and their corresponding values are hash
references used to construct a L<CGI::Simple::Cookie> object.

    $c->response->cookies->{foo} = { value => '123' };

The keys of the hash reference on the right correspond to the L<CGI::Simple::Cookie>
parameters of the same name, except they are used without a leading dash.
Possible parameters are:

=over

=item value

=item expires

=item domain

=item path

=item secure

=item httponly

=back

=head2 $res->header

Shortcut for $res->headers->header.

=head2 $res->headers

Returns an L<HTTP::Headers> object, which can be used to set headers.

    $c->response->headers->header( 'X-Catalyst' => $Catalyst::VERSION );

=head2 $res->output

Alias for $res->body.

=head2 $res->redirect( $url, $status )

Causes the response to redirect to the specified URL. The default status is
C<302>.

    $c->response->redirect( 'http://slashdot.org' );
    $c->response->redirect( 'http://slashdot.org', 307 );

This is a convenience method that sets the Location header to the
redirect destination, and then sets the response status.  You will
want to C< return > or C<< $c->detach() >> to interrupt the normal
processing flow if you want the redirect to occur straight away.

B<Note:> do not give a relative URL as $url, i.e: one that is not fully
qualified (= C<http://...>, etc.) or that starts with a slash
(= C</path/here>). While it may work, it is not guaranteed to do the right
thing and is not a standard behaviour. You may opt to use uri_for() or
uri_for_action() instead.

=cut

sub redirect {
    my $self = shift;

    if (@_) {
        my $location = shift;
        my $status   = shift || 302;

        $self->location($location);
        $self->status($status);
    }

    return $self->location;
}

=head2 $res->location

Sets or returns the HTTP 'Location'.

=head2 $res->status

Sets or returns the HTTP status.

    $c->response->status(404);

$res->code is an alias for this, to match HTTP::Response->code.

=head2 $res->write( $data )

Writes $data to the output stream.

=head2 $res->write_fh

Returns a PSGI $writer object that has two methods, write and close.  You can
close over this object for asynchronous and nonblocking applications.  For
example (assuming you are using a supporting server, like L<Twiggy>

    package AsyncExample::Controller::Root;

    use Moose;

    BEGIN { extends 'Catalyst::Controller' }

    sub prepare_cb {
      my $write_fh = pop;
      return sub {
        my $message = shift;
        $write_fh->write("Finishing: $message\n");
        $write_fh->close;
      };
    }

    sub anyevent :Local :Args(0) {
      my ($self, $c) = @_;
      my $cb = $self->prepare_cb($c->res->write_fh);

      my $watcher;
      $watcher = AnyEvent->timer(
        after => 5,
        cb => sub {
          $cb->(scalar localtime);
          undef $watcher; # cancel circular-ref
        });
    }

=head2 $res->print( @data )

Prints @data to the output stream, separated by $,.  This lets you pass
the response object to functions that want to write to an L<IO::Handle>.

=head2 $self->finalize_headers($c)

Writes headers to response if not already written

=head2 from_psgi_response

Given a PSGI response (either three element ARRAY reference OR coderef expecting
a $responder) set the response from it.

Properly supports streaming and delayed response and / or async IO if running
under an expected event loop.

Example:

    package MyApp::Web::Controller::Test;

    use base 'Catalyst::Controller';
    use Plack::App::Directory;


    my $app = Plack::App::Directory->new({ root => "/path/to/htdocs" })
      ->to_app;

    sub myaction :Local Args {
      my ($self, $c) = @_;
      $c->res->from_psgi_response($app->($c->req->env));
    }

Please note this does not attempt to map or nest your PSGI application under
the Controller and Action namespace or path.  

=head2 DEMOLISH

Ensures that the response is flushed and closed at the end of the
request.

=head2 meta

Provided by Moose

=cut

sub print {
    my $self = shift;
    my $data = shift;

    defined $self->write($data) or return;

    for (@_) {
        defined $self->write($,) or return;
        defined $self->write($_) or return;
    }
    defined $self->write($\) or return;

    return 1;
}

=head1 AUTHORS

Catalyst Contributors, see Catalyst.pm

=head1 COPYRIGHT

This library is free software. You can redistribute it and/or modify
it under the same terms as Perl itself.

=cut

__PACKAGE__->meta->make_immutable;

1;