A Perl port of Webmachine
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Web::Machine - A Perl port of Webmachine


version 0.17


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, actually it is much closer to the Ruby version, with a little bit of the JavaScript version and even some of the Python version thrown in for good measure.

You can learn a bit about Web::Machine's history from the slides for my 2012 YAPC::NA talk.

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 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.

  • create_fsm

    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.



bugs may be submitted through https://github.com/houseabsolute/webmachine-perl/issues.




This software is copyright (c) 2016 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.