Webmachine.rb is a port of Webmachine, which is written in Erlang. The goal of both projects is to expose interesting parts of the HTTP protocol to your application in a declarative way. This means that you are less concerned with handling requests directly and more with describing the behavior of the resources that make up your application. Webmachine is not a web framework per se, but more of a toolkit for building HTTP-friendly applications. For example, it does not provide a templating engine or a persistence layer; those choices are up to you.
NOTE: Webmachine is NOT compatible with Rack. This is intentional! Rack obscures HTTP in a way that makes it hard for Webmachine to do its job properly, and encourages people to add middleware that might break Webmachine's behavior. Rack is also built on the tradition of CGI, which is nice for backwards compatibility but also an antiquated paradigm and should be scuttled (IMHO).
Webmachine.rb is not fully-functional yet, but constructing an application for it will follow this general outline:
require 'webmachine' # Require any of the files that contain your resources here require 'my_resource' # Point all URIs at the MyResource class Webmachine::Dispatcher.add_route(['*'], MyResource) # Start the server, binds to the default interface/port Webmachine.run
Your resource will look something like this:
class MyResource < Webmachine::Resource def to_html "<html><body>Hello, world!</body></html>" end end
Run the first file and your application is up. That's all there is to it! If you want to customize your resource more, look at the available callbacks in lib/webmachine/resource/callbacks.rb.
- Handles the hard parts of content negotiation, conditional requests, and response codes for you.
- Most callbacks can interrupt the decision flow by returning an integer response code. You generally only want to do this when new information comes to light, requiring a modification of the response.
- Streaming and range responses will be supported as soon as API is decided on.
- EventMachine and Mongrel2 will be supported as host servers. Pieces of the Mongrel2 API are already in there.
- Configuration, command-line tools, and general polish.
- An effort has been made to make the code feel as Ruby-ish as possible, but there is still work to do.
- There are no tests. The first step will be porting existing tests from Erlang webmachine. A testing framework has not yet been chosen.
- One of the coolest features of Erlang webmachine is the tracing feature. This should be simple to add to the FSM.