aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/action_controller/metal.rb
blob: 030a1f3478f776d87ff8168a73ca5ff7f6fe6054 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
require 'active_support/core_ext/array/extract_options'
require 'action_dispatch/middleware/stack'
require 'active_support/deprecation'
require 'action_dispatch/http/request'
require 'action_dispatch/http/response'

module ActionController
  # Extend ActionDispatch middleware stack to make it aware of options
  # allowing the following syntax in controllers:
  #
  #   class PostsController < ApplicationController
  #     use AuthenticationMiddleware, except: [:index, :show]
  #   end
  #
  class MiddlewareStack < ActionDispatch::MiddlewareStack #:nodoc:
    class Middleware < ActionDispatch::MiddlewareStack::Middleware #:nodoc:
      def initialize(klass, args, actions, strategy, block)
        @actions = actions
        @strategy = strategy
        super(klass, args, block)
      end

      def valid?(action)
        @strategy.call @actions, action
      end
    end

    def build(action, app = Proc.new)
      action = action.to_s

      middlewares.reverse.inject(app) do |a, middleware|
        middleware.valid?(action) ? middleware.build(a) : a
      end
    end

    private

    INCLUDE = ->(list, action) { list.include? action }
    EXCLUDE = ->(list, action) { !list.include? action }
    NULL    = ->(list, action) { true }

    def build_middleware(klass, args, block)
      options = args.extract_options!
      only   = Array(options.delete(:only)).map(&:to_s)
      except = Array(options.delete(:except)).map(&:to_s)
      args << options unless options.empty?

      strategy = NULL
      list     = nil

      if only.any?
        strategy = INCLUDE
        list     = only
      elsif except.any?
        strategy = EXCLUDE
        list     = except
      end

      Middleware.new(get_class(klass), args, list, strategy, block)
    end
  end

  # <tt>ActionController::Metal</tt> is the simplest possible controller, providing a
  # valid Rack interface without the additional niceties provided by
  # <tt>ActionController::Base</tt>.
  #
  # A sample metal controller might look like this:
  #
  #   class HelloController < ActionController::Metal
  #     def index
  #       self.response_body = "Hello World!"
  #     end
  #   end
  #
  # And then to route requests to your metal controller, you would add
  # something like this to <tt>config/routes.rb</tt>:
  #
  #   get 'hello', to: HelloController.action(:index)
  #
  # The +action+ method returns a valid Rack application for the \Rails
  # router to dispatch to.
  #
  # == Rendering Helpers
  #
  # <tt>ActionController::Metal</tt> by default provides no utilities for rendering
  # views, partials, or other responses aside from explicitly calling of
  # <tt>response_body=</tt>, <tt>content_type=</tt>, and <tt>status=</tt>. To
  # add the render helpers you're used to having in a normal controller, you
  # can do the following:
  #
  #   class HelloController < ActionController::Metal
  #     include AbstractController::Rendering
  #     include ActionView::Layouts
  #     append_view_path "#{Rails.root}/app/views"
  #
  #     def index
  #       render "hello/index"
  #     end
  #   end
  #
  # == Redirection Helpers
  #
  # To add redirection helpers to your metal controller, do the following:
  #
  #   class HelloController < ActionController::Metal
  #     include ActionController::Redirecting
  #     include Rails.application.routes.url_helpers
  #
  #     def index
  #       redirect_to root_url
  #     end
  #   end
  #
  # == Other Helpers
  #
  # You can refer to the modules included in <tt>ActionController::Base</tt> to see
  # other features you can bring into your metal controller.
  #
  class Metal < AbstractController::Base
    abstract!

    def env
      @_request.env
    end
    deprecate :env

    # Returns the last part of the controller's name, underscored, without the ending
    # <tt>Controller</tt>. For instance, PostsController returns <tt>posts</tt>.
    # Namespaces are left out, so Admin::PostsController returns <tt>posts</tt> as well.
    #
    # ==== Returns
    # * <tt>string</tt>
    def self.controller_name
      @controller_name ||= name.demodulize.sub(/Controller$/, '').underscore
    end

    def self.make_response!(request)
      ActionDispatch::Response.new.tap do |res|
        res.request = request
      end
    end

    def self.build_with_env(env = {}) #:nodoc:
      new.tap { |c|
        c.set_request! ActionDispatch::Request.new(env)
        c.set_response! make_response!(c.request)
      }
    end

    # Delegates to the class' <tt>controller_name</tt>
    def controller_name
      self.class.controller_name
    end

    attr_internal :response, :request
    delegate :session, :to => "@_request"
    delegate :headers, :status=, :location=, :content_type=,
             :status, :location, :content_type, :to => "@_response"

    def initialize
      @_request = nil
      @_response = nil
      @_routes = nil
      super
    end

    def params
      @_params ||= request.parameters
    end

    def params=(val)
      @_params = val
    end

    alias :response_code :status # :nodoc:

    # Basic url_for that can be overridden for more robust functionality
    def url_for(string)
      string
    end

    def response_body=(body)
      body = [body] unless body.nil? || body.respond_to?(:each)
      response.body = body
      super
    end

    # Tests if render or redirect has already happened.
    def performed?
      response_body || response.committed?
    end

    def dispatch(name, request, response) #:nodoc:
      set_request!(request)
      set_response!(response)
      process(name)
      to_a
    end

    def set_response!(response) # :nodoc:
      @_response = response
    end

    def set_request!(request) #:nodoc:
      @_request = request
      @_request.controller_instance = self
    end

    def to_a #:nodoc:
      response.to_a
    end

    def reset_session
      @_request.reset_session
    end

    class_attribute :middleware_stack
    self.middleware_stack = ActionController::MiddlewareStack.new

    def self.inherited(base) # :nodoc:
      base.middleware_stack = middleware_stack.dup
      super
    end

    # Pushes the given Rack middleware and its arguments to the bottom of the
    # middleware stack.
    def self.use(*args, &block)
      middleware_stack.use(*args, &block)
    end

    # Alias for +middleware_stack+.
    def self.middleware
      middleware_stack
    end

    # Makes the controller a Rack endpoint that runs the action in the given
    # +env+'s +action_dispatch.request.path_parameters+ key.
    def self.call(env)
      req = ActionDispatch::Request.new env
      action(req.path_parameters[:action]).call(env)
    end
    class << self; deprecate :call; end

    # Returns a Rack endpoint for the given action name.
    def self.action(name)
      if middleware_stack.any?
        middleware_stack.build(name) do |env|
          req = ActionDispatch::Request.new(env)
          res = make_response! req
          new.dispatch(name, req, res)
        end
      else
        lambda { |env|
          req = ActionDispatch::Request.new(env)
          res = make_response! req
          new.dispatch(name, req, res)
        }
      end
    end

    # Direct dispatch to the controller.  Instantiates the controller, then
    # executes the action named +name+.
    def self.dispatch(name, req, res)
      if middleware_stack.any?
        middleware_stack.build(name) { |env| new.dispatch(name, req, res) }.call req.env
      else
        new.dispatch(name, req, res)
      end
    end
  end
end