aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
blob: 2e116ea9cdfbd226b194fc8db7fbaec8541d7042 (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
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
module ActionDispatch
  module Routing
    # Polymorphic URL helpers are methods for smart resolution to a named route call when
    # given an Active Record model instance. They are to be used in combination with
    # ActionController::Resources.
    #
    # These methods are useful when you want to generate correct URL or path to a RESTful
    # resource without having to know the exact type of the record in question.
    #
    # Nested resources and/or namespaces are also supported, as illustrated in the example:
    #
    #   polymorphic_url([:admin, @article, @comment])
    #
    # results in:
    #
    #   admin_article_comment_url(@article, @comment)
    #
    # == Usage within the framework
    #
    # Polymorphic URL helpers are used in a number of places throughout the \Rails framework:
    #
    # * <tt>url_for</tt>, so you can use it with a record as the argument, e.g.
    #   <tt>url_for(@article)</tt>;
    # * ActionView::Helpers::FormHelper uses <tt>polymorphic_path</tt>, so you can write
    #   <tt>form_for(@article)</tt> without having to specify <tt>:url</tt> parameter for the form
    #   action;
    # * <tt>redirect_to</tt> (which, in fact, uses <tt>url_for</tt>) so you can write
    #   <tt>redirect_to(post)</tt> in your controllers;
    # * ActionView::Helpers::AtomFeedHelper, so you don't have to explicitly specify URLs
    #   for feed entries.
    #
    # == Prefixed polymorphic helpers
    #
    # In addition to <tt>polymorphic_url</tt> and <tt>polymorphic_path</tt> methods, a
    # number of prefixed helpers are available as a shorthand to <tt>action: "..."</tt>
    # in options. Those are:
    #
    # * <tt>edit_polymorphic_url</tt>, <tt>edit_polymorphic_path</tt>
    # * <tt>new_polymorphic_url</tt>, <tt>new_polymorphic_path</tt>
    #
    # Example usage:
    #
    #   edit_polymorphic_path(@post)              # => "/posts/1/edit"
    #   polymorphic_path(@post, format: :pdf)  # => "/posts/1.pdf"
    #
    # == Usage with mounted engines
    #
    # If you are using a mounted engine and you need to use a polymorphic_url
    # pointing at the engine's routes, pass in the engine's route proxy as the first
    # argument to the method. For example:
    #
    #   polymorphic_url([blog, @post])  # calls blog.post_path(@post)
    #   form_for([blog, @post])         # => "/blog/posts/1"
    #
    module PolymorphicRoutes
      # Constructs a call to a named RESTful route for the given record and returns the
      # resulting URL string. For example:
      #
      #   # calls post_url(post)
      #   polymorphic_url(post) # => "http://example.com/posts/1"
      #   polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
      #   polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
      #   polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
      #   polymorphic_url(Comment) # => "http://example.com/comments"
      #
      # ==== Options
      #
      # * <tt>:action</tt> - Specifies the action prefix for the named route:
      #   <tt>:new</tt> or <tt>:edit</tt>. Default is no prefix.
      # * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
      #   Default is <tt>:url</tt>.
      #
      # Also includes all the options from <tt>url_for</tt>. These include such
      # things as <tt>:anchor</tt> or <tt>:trailing_slash</tt>. Example usage
      # is given below:
      #
      #   polymorphic_url([blog, post], anchor: 'my_anchor')
      #     # => "http://example.com/blogs/1/posts/1#my_anchor"
      #   polymorphic_url([blog, post], anchor: 'my_anchor', script_name: "/my_app")
      #     # => "http://example.com/my_app/blogs/1/posts/1#my_anchor"
      #
      # For all of these options, see the documentation for <tt>url_for</tt>.
      #
      # ==== Functionality
      #
      #   # an Article record
      #   polymorphic_url(record)  # same as article_url(record)
      #
      #   # a Comment record
      #   polymorphic_url(record)  # same as comment_url(record)
      #
      #   # it recognizes new records and maps to the collection
      #   record = Comment.new
      #   polymorphic_url(record)  # same as comments_url()
      #
      #   # the class of a record will also map to the collection
      #   polymorphic_url(Comment) # same as comments_url()
      #
      def polymorphic_url(record_or_hash_or_array, options = {})
        if Hash === record_or_hash_or_array
          options = record_or_hash_or_array.merge(options)
          record  = options.delete :id
          return polymorphic_url record, options
        end

        opts   = options.dup
        action = opts.delete :action
        type   = opts.delete(:routing_type) || :url

        HelperMethodBuilder.polymorphic_method self,
                                               record_or_hash_or_array,
                                               action,
                                               type,
                                               opts
      end

      # Returns the path component of a URL for the given record. It uses
      # <tt>polymorphic_url</tt> with <tt>routing_type: :path</tt>.
      def polymorphic_path(record_or_hash_or_array, options = {})
        if Hash === record_or_hash_or_array
          options = record_or_hash_or_array.merge(options)
          record  = options.delete :id
          return polymorphic_path record, options
        end

        opts   = options.dup
        action = opts.delete :action
        type   = :path

        HelperMethodBuilder.polymorphic_method self,
                                               record_or_hash_or_array,
                                               action,
                                               type,
                                               opts
      end


      %w(edit new).each do |action|
        module_eval <<-EOT, __FILE__, __LINE__ + 1
          def #{action}_polymorphic_url(record_or_hash, options = {})
            polymorphic_url_for_action("#{action}", record_or_hash, options)
          end

          def #{action}_polymorphic_path(record_or_hash, options = {})
            polymorphic_path_for_action("#{action}", record_or_hash, options)
          end
        EOT
      end

      private

      def polymorphic_url_for_action(action, record_or_hash, options)
        polymorphic_url(record_or_hash, options.merge(:action => action))
      end

      def polymorphic_path_for_action(action, record_or_hash, options)
        polymorphic_path(record_or_hash, options.merge(:action => action))
      end

      class HelperMethodBuilder # :nodoc:
        CACHE = { 'path' => {}, 'url' => {} }

        def self.get(action, type)
          type   = type.to_s
          CACHE[type].fetch(action) { build action, type }
        end

        def self.url;  CACHE['url'.freeze][nil]; end
        def self.path; CACHE['path'.freeze][nil]; end

        def self.build(action, type)
          prefix = action ? "#{action}_" : ""
          suffix = type
          if action.to_s == 'new'
            HelperMethodBuilder.singular prefix, suffix
          else
            HelperMethodBuilder.plural prefix, suffix
          end
        end

        def self.singular(prefix, suffix)
          new(->(name) { name.singular_route_key }, prefix, suffix)
        end

        def self.plural(prefix, suffix)
          new(->(name) { name.route_key }, prefix, suffix)
        end

        def self.polymorphic_method(recipient, record_or_hash_or_array, action, type, options)
          builder = get action, type

          case record_or_hash_or_array
          when Array
            record_or_hash_or_array = record_or_hash_or_array.compact
            if record_or_hash_or_array.empty?
              raise ArgumentError, "Nil location provided. Can't build URI."
            end
            if record_or_hash_or_array.first.is_a?(ActionDispatch::Routing::RoutesProxy)
              recipient = record_or_hash_or_array.shift
            end

            method, args = builder.handle_list record_or_hash_or_array
          when String, Symbol
            method, args = builder.handle_string record_or_hash_or_array
          when Class
            method, args = builder.handle_class record_or_hash_or_array

          when nil
            raise ArgumentError, "Nil location provided. Can't build URI."
          else
            method, args = builder.handle_model record_or_hash_or_array
          end


          if options.empty?
            recipient.send(method, *args)
          else
            recipient.send(method, *args, options)
          end
        end

        attr_reader :suffix, :prefix

        def initialize(key_strategy, prefix, suffix)
          @key_strategy = key_strategy
          @prefix       = prefix
          @suffix       = suffix
        end

        def handle_string(record)
          [get_method_for_string(record), []]
        end

        def handle_string_call(target, str)
          target.send get_method_for_string str
        end

        def handle_class(klass)
          [get_method_for_class(klass), []]
        end

        def handle_class_call(target, klass)
          target.send get_method_for_class klass
        end

        def handle_model(record)
          args  = []

          model = record.to_model
          name = if model.persisted?
                   args << model
                   model.model_name.singular_route_key
                 else
                   @key_strategy.call model.model_name
                 end

          named_route = prefix + "#{name}_#{suffix}"

          [named_route, args]
        end

        def handle_model_call(target, model)
          method, args = handle_model model
          target.send(method, *args)
        end

        def handle_list(list)
          record_list = list.dup
          record      = record_list.pop

          args = []

          route  = record_list.map { |parent|
            case parent
            when Symbol, String
              parent.to_s
            when Class
              args << parent
              parent.model_name.singular_route_key
            else
              args << parent.to_model
              parent.to_model.model_name.singular_route_key
            end
          }

          route <<
          case record
          when Symbol, String
            record.to_s
          when Class
            @key_strategy.call record.model_name
          else
            model = record.to_model
            if model.persisted?
              args << model
              model.model_name.singular_route_key
            else
              @key_strategy.call model.model_name
            end
          end

          route << suffix

          named_route = prefix + route.join("_")
          [named_route, args]
        end

        private

        def get_method_for_class(klass)
          name   = @key_strategy.call klass.model_name
          prefix + "#{name}_#{suffix}"
        end

        def get_method_for_string(str)
          prefix + "#{str}_#{suffix}"
        end

        [nil, 'new', 'edit'].each do |action|
          CACHE['url'][action]  = build action, 'url'
          CACHE['path'][action] = build action, 'path'
        end
      end
    end
  end
end