NAME

Mason::Plugin::PSGIHandler - PSGI handler for Mason

SYNOPSIS

    # Quick start:
    mason_psgi_setup myapp

    # app.psgi
    use Mason;
    use Plack::Builder;
    my $interp = Mason->new(
         plugins => ['PSGIHandler', ...],
         comp_root => '/path/to/comp_root/',
         data_dir => '/path/to/data_dir/',
    );
    my $app = sub {
        my $env = shift;
        $interp->handle_psgi($env);
    };
    builder {
        # Include PSGI middleware here
        $app;
    };

DESCRIPTION

Provides a PSGI handler for Mason. It allows Mason to handle requests directly from any web servers that support PSGI.

Run path

The top-level run path is taken from the method "path" in Plack::Request. So in a simple Plack configuration like the one above, a URL like

    /foo/bar

would result in

    $interp->run("/foo/bar");

However, if you mounted your Mason app under "/mason",

    builder {
        mount "/mason" => builder {
            $app;
        };
        mount "/other" => $other_app;
        ...
    };

then the "/mason" portion of the URL would get stripped off in the top-level run path.

Run parameters

The top-level run parameters are taken from the method "parameters" in Plack::Request, which combines GET and POST parameters. So

    /foo/bar?a=5&b=6

would generally result in

    $interp->run("/foo/bar", a=>5, b=>6);

If there are multiple values for a parameter, generally only the last value will be kept, as per Hash::MultiValue. However, if the corresponding attribute in the page component is declared an ArrayRef, then all values will be kept and passed in as an arrayref. For example, if the page component /foo/bar.mc has these declarations:

    <%args>
    $.a
    $.b => (isa => "Int")
    $.c => (isa => "ArrayRef");
    $.d => (isa => "ArrayRef[Int]");
    </%args>

then this URL

    /foo/bar?a=1&a=2&b=3&b=4&c=5&c=6&d=7&d=8

would result in

    $interp->run("/foo/bar", a=>2, b=>4, c=>[5,6], d => [7,8]);

You can always get the original Hash::MultiValue object from $m->request_args. e.g.

    my $hmv = $m->request_args;
    # get all values for 'e'
    $hmv->get_all('e');

Plack request object

A Mason::Plack::Request is constructed from the plack environment and made available in $m->req. This is a thin subclass of Plack::Request and provides information such as the URL and incoming HTTP headers. e.g.

    my $headers = $m->req->headers;
    my $cookie = $m->req->cookies->{'foo'};

Plack response object

An empty Mason::Plack::Response is constructed and made available in $m->res. Your Mason components are responsible for setting the status and headers, by calling $m->res->status and $m->res->headers or utility methods that do so. e.g.

    $m->res->content_type('text/plain');
    $m->res->cookies->{foo} = { value => 123 };

    $m->redirect('http://www.google.com/', 301)  # sets header/status and aborts
    $m->clear_and_abort(404);   # sets status and aborts

If the Mason request finishes successfully, the Mason output becomes the plack response body; any value explicitly set in $m->res->body is ignored and overwritten. $m->res->status is set to 200 if it hasn't already been set.

If the top-level component path cannot be found, $m->res->status is set to 404. All other runtime errors fall through to be handled by Plack, i.e. with Plack::Middleware::StackTrace in development mode or a 500 error response in deployment mode.

INTERP METHODS

handle_psgi ($env)

Takes a PSGI environment hash, calls an appropriate Mason request as detailed above, and returns a standard PSGI response array.

REQUEST METHODS

req ()

A reference to the Mason::Plack::Request.

res ()

A reference to the Mason::Plack::Response.

redirect (url[, status])

Sets headers and status for redirect, then clears the Mason buffer and aborts the request. e.g.

    $m->redirect("http://somesite.com", 302);

is equivalent to

    $m->res->redirect("http://somesite.com", 302);
    $m->clear_and_abort();

not_found ()

Sets the status to 404, then clears the Mason buffer and aborts the request. Equivalent to

    $m->res->status(404);
    $m->clear_and_abort();

abort (status)

clear_and_abort (status)

These methods are overriden to set the response status before aborting, if status is provided. e.g. to send back a NOT FOUND result:

    $m->clear_and_abort(404);

This is equivalent to

    $m->res->status(404);
    $m->clear_and_abort();

SUPPORT

The mailing list for Mason and Mason plugins is mason-users@lists.sourceforge.net. You must be subscribed to send a message. To subscribe, visit https://lists.sourceforge.net/lists/listinfo/mason-users.

You can also visit us at #mason on irc://irc.perl.org/#mason.

Bugs and feature requests will be tracked at RT:

    http://rt.cpan.org/NoAuth/Bugs.html?Dist=Mason-Plugin-PSGIHandler
    bug-mason-plugin-psgihandler@rt.cpan.org

The latest source code can be browsed and fetched at:

    http://github.com/jonswar/perl-mason-plugin-psgihandler
    git clone git://github.com/jonswar/perl-mason-plugin-psgihandler.git

SEE ALSO

Mason, http://plackperl.org/|PSGI

cpanm Mason::Plugin::PSGIHandler

perl -MCPAN -e shell
install Mason::Plugin::PSGIHandler