NAME
Plack::Middleware::REST - Route PSGI requests for RESTful web applications
SYNOPSIS
# $get, $update, $delete, $create, $list, $patch, $app must be PSGI applications
builder {
enable 'REST',
get => $get, # GET /{id}
upsert => $update, # PUT /{id}
delete => $delete, # DELETE /{id}
create => $create, # POST /
list => $list, # GET /
patch => $patch, # PATCH /{id}
head => 1, # HEAD /{$id} => $get, HEAD / => $list
options => 1, # support OPTIONS requests
pass_through => 1, # pass everything else to $app
patch_types => ['text/plain']; # optional accepted patch types
$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, list, and patch 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 byhttp://example.org/item/123
. PUT http://example.org/item/123
-
Calls the PSGI application
upsert
to either update an existing resource identified byhttp://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 byhttp://example.org/item/123
. GET http://example.org/item/
-
Calls the PSGI application
list
to get a list of existing resources. PATCH http://example.org/item/123
-
Calls the PSGI application
patch
to update an existing resource identified byhttp://example.org/item/123
. The application may reject updates of resources. OPTIONS http://example.org/item/
-
Calls the PSGI application to return the allowed methods for the resource.
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
get
create
upsert
delete
list
patch
The options get
, create
, upsert
, delete
, list
, patch
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;
};
head
By default (head => 1
) the app configured to get
and/or list
resources are also assumed to handle HEAD requests. Setting this configuration to 0
will disallow HEAD requests. The special value auto
will rewrite HEAD requests with Plack::Middleware::Head.
options
By default (options => 1
) the app is configured to handle OPTIONS requests for a resource. Setting this configuration to 0
will dissallow OPTIONS requests.
pass_through
Respond to not allowed requests with HTTP 405. Enabled by default, but this may change in a future version of this module!
patch_types
Optional array of acceptable patch document types for PATCH requests. Respond to unacceptable patch document types with HTTP 415.
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, included with Plack::Middleware::REST provides some utility methods to implement RESTful PSGI applications. The module may be removed in a future release.
See Plack::Middleware::Negotiate for content negotiation.
See Plack::Middleware::ETag for ETag generation.
Alternative CPAN modules with similar scope include Apache2::REST, REST::Utils, REST::Application, WWW::REST::Apid, WWW::REST::Simple, CGI::Application::Plugin::REST, and Plack::App::REST. Moreover there are general web application frameworks like Dancer/Dancer2, Mojolicious, and Catalyst. Maybe the number of such modules and frameworks is higher than the number of actual web APIs written in Perl. Who knows?
REST client modules at CPAN include REST::Client, Eixo::Rest, REST::Consumer, Net::Rest::Generic, LWP::Simple::REST, and WWW:.REST, Role::REST::Client, Rest::Client::Builder, MooseX::Role::REST::Consumer. Don't ask why.