Web::Machine(3) A Perl port of Webmachine


version 0.16


use strict;
use warnings;
use Web::Machine;
package HelloWorld::Resource;
use strict;
use warnings;
use parent 'Web::Machine::Resource';
sub content_types_provided { [{ 'text/html' => 'to_html' }] }
sub to_html {
<title>Hello World Resource</title>
<h1>Hello World</h1>
Web::Machine->new( resource => 'HelloWorld::Resource' )->to_app;


"Web::Machine" provides a RESTful web framework modeled as a state machine. You define one or more resource classes. Each resource represents a single RESTful URI end point, such as a user, an email, etc. The resource class can also be the target for "POST" requests to create a new user, email, etc.

Each resource is a state machine, and each request for a resource is handled by running the request through that state machine.

"Web::Machine" is built on top of Plack, but it handles the full request and response cycle.

See Web::Machine::Manual for more details on using "Web::Machine" in general, and how "Web::Machine" and Plack interact.

This is a port of Webmachine <https://github.com/basho/webmachine>, actually it is much closer to the Ruby version <https://github.com/seancribbs/webmachine-ruby>, with a little bit of the JavaScript version <https://github.com/tautologistics/nodemachine> and even some of the Python version <https://github.com/benoitc/pywebmachine> thrown in for good measure.

You can learn a bit about Web::Machine's history from the slides for my 2012 YAPC::NA talk <https://speakerdeck.com/stevan_little/rest-from-the-trenches>.

To learn more about Webmachine, take a look at the links in the SEE ALSO section.


NOTE: This module is a Plack::Component subclass and so follows the interface set forward by that module.
"new( resource => $resource_classname, ?resource_args => $arg_list, ?tracing => 1|0, ?streaming => 1|0, ?request_class => $request_class )"
The constructor expects to get a $resource_classname, which it will use to load and create an instance of the resource class. If that class requires any additional arguments, they can be specified with the "resource_args" parameter. The contents of the "resource_args" parameter will be made available to the "init()" method of "Web::Machine::Resource".

The "new" method can also take an optional "tracing" parameter which it will pass on to Web::Machine::FSM and an optional "streaming" parameter, which if true will run the request in a PSGI <http://plackperl.org/> streaming response. This can be useful if you need to run your content generation asynchronously.

The optional "request_class" parameter accepts the name of a module that will be used as the request object. The module must be a class that inherits from Plack::Request. Use this if you have a subclass of Plack::Request that you would like to use in your Web::Machine::Resource.

"inflate_request( $env )"
This takes a raw PSGI $env and inflates it into a Plack::Request instance. By default this also uses HTTP::Headers::ActionPack to inflate the headers of the request to be complex objects.
This will create the Web::Machine::FSM object to run. It will get passed the value of the "tracing" constructor parameter.
"create_resource( $request )"
This will create the Web::Machine::Resource instance using the class specified in the "resource" constructor parameter. It will pass in the $request object and call "new_response" on the $request object to get a Plack::Response instance.
"finalize_response( $response )"
Given a $response which is a Plack::Response object, this will finalize it and return a raw PSGI response.
"call( $env )"
This is the "call" method overridden from the Plack::Component superclass.


If you set the "WM_DEBUG" environment variable to 1 we will print out information about the path taken through the state machine to STDERR.

If you set "WM_DEBUG" to "diag" then debugging information will be printed using Test::More's "diag()" sub instead.




This software is copyright (c) 2015 by Infinity Interactive, Inc..

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.