NAME

Plack::Middleware::REST - Route PSGI requests for RESTful web applications

STATUS

SYNOPSIS

# $get, $create, $update, $list, $app must be PSGI applications
builder {
    enable 'REST',
        get          => $get,      # HTTP GET on a resource
        create       => $create,   # HTTP POST in '/'
        upsert       => $update,   # HTTP PUT on a resource
        list         => $list,     # HTTP GET on '/'
        pass_through => 1;         # pass if no defined REST request
    $app;
};

DESCRIPTION

Plack::Middleware::REST routes HTTP requests (given in PSGI request format) on the principles of Representational State Transfer (REST). In short, the application manages a set of resources with common base URL, each identified by its URL. One can retrieve, create, update, delete, and list resources based on HTTP request methods.

Let's say an instance of Plack::Middleware::REST is mounted at the base URL http://example.org/item/. The following HTTP request types can be recognized, once they have been assigned:

• POST http://example.org/item/

  Calls the PSGI application create to create a new resource with URL assigned by the application.

• GET http://example.org/item/123

  Calls the application get to retrieve an existing resource identified by http://example.org/item/123.

• PUT http://example.org/item/123

  Calls the PSGI application upsert to either update an existing resource identified by http://example.org/item/123 or to create a new resource with this URL. The application may reject updates and/or creation of new resources, acting like an update or insert method.

• DELETE http://example.org/item/123

  Calls the PSGI application delete to delete an existing resource identified by http://example.org/item/123.

• GET http://example.org/item/

  Calls the PSGI application list to get a list of existing resources.

Additional HTTP request types HEAD, OPTIONS, and PATCH may be added in a later version of this module.

Other requests result either result in a PSGI response with error code 405 and a list of possible request types in the Accept header, or the request is passed to the underlying application in the middleware stack, if option pass_through is set.

CONFIGURATION

The options get, create, upsert, delete, list can be set to PSGI applications to enable the corresponding REST request type. One can also use string aliases, including app to pass the request in the middleware stack:

builder {
    enable 'REST',
        get          => 'app',   # pass GET requests on resource to $wrapped
        create       => $create, # pass POST to base URL to $create
        upsert       => $update; # pass PUT requests on resources to $update
        pass_through => 0;       # respond other requests with 405
    $wrapped;
};

COPYRIGHT AND LICENSE

Copyright 2014- Jakob Voß

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

CONTRIBUTORS

Jakob Voß and Chris Kirke

SEE ALSO

Plack::Middleware::REST::Util provides some utility methods to implement RESTful PSGI applications with Plack::Middleware::REST. See Plack::Middleware::Negotiate for content negotiation.