Ruby / Roda - Web Framework / Plugins / :not_allowed

Introduction

The :not_allowed plugin makes Roda attempt to automatically support the 405 Method Not Allowed response status.

The plugin changes the r.get and r.post verb methods to automatically return a 405 status if they are called with any arguments, and the arguments match but the request method does not match.

So this code:

r.get '' do
  'a'
end

will return a 200 response for GET / and a 405 response for POST /.

This plugin also changes the r.is method so that if you use a verb method inside r.is, it returns a 405 status if none of the verb methods match.

So this code:

r.is '' do
    r.get do
      "a"
    end

    r.post do
      "b"
    end
  end

will return a 200 response for GET / and POST /, but a 405 response for PUT /.

Note! This plugin will probably not do what you want for code such as:

r.get '' do
  'a'
end

r.post '' do
  'b'
end

Since for a POST / request, when +r.get+ method matches the path but not the request method, it will return an immediate 405 response.

You must DRY up this code for it work correctly, like this:

r.is '' do

  r.get do
    'a'
  end

  r.post do
    'b'
  end
  
end

In all cases where it uses a 405 response, it also sets the Allow header in the response to contain the request methods supported.

This plugin depends on the :all_verbs plugin. It works by overriding the verb methods, so it wouldn't work if loaded after the :all_verbs plugin.