aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/action_controller/routing/builder.rb
blob: 69943d4230565e18d6084021a67a892bde50d383 (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
module ActionController
  module Routing
    class RouteBuilder #:nodoc:
      attr_accessor :separators, :optional_separators

      def initialize
        self.separators = Routing::SEPARATORS
        self.optional_separators = %w( / )
      end

      def separator_pattern(inverted = false)
        "[#{'^' if inverted}#{Regexp.escape(separators.join)}]"
      end

      def interval_regexp
        Regexp.new "(.*?)(#{separators.source}|$)"
      end

      # Accepts a "route path" (a string defining a route), and returns the array
      # of segments that corresponds to it. Note that the segment array is only
      # partially initialized--the defaults and requirements, for instance, need
      # to be set separately, via the #assign_route_options method, and the
      # #optional? method for each segment will not be reliable until after
      # #assign_route_options is called, as well.
      def segments_for_route_path(path)
        rest, segments = path, []

        until rest.empty?
          segment, rest = segment_for rest
          segments << segment
        end
        segments
      end

      # A factory method that returns a new segment instance appropriate for the
      # format of the given string.
      def segment_for(string)
        segment = case string
          when /\A:(\w+)/
            key = $1.to_sym
            case key
              when :controller then ControllerSegment.new(key)
              else DynamicSegment.new key
            end
          when /\A\*(\w+)/ then PathSegment.new($1.to_sym, :optional => true)
          when /\A\?(.*?)\?/
            returning segment = StaticSegment.new($1) do
              segment.is_optional = true
            end
          when /\A(#{separator_pattern(:inverted)}+)/ then StaticSegment.new($1)
          when Regexp.new(separator_pattern) then
            returning segment = DividerSegment.new($&) do
              segment.is_optional = (optional_separators.include? $&)
            end
        end
        [segment, $~.post_match]
      end

      # Split the given hash of options into requirement and default hashes. The
      # segments are passed alongside in order to distinguish between default values
      # and requirements.
      def divide_route_options(segments, options)
        options = options.dup

        if options[:namespace]
          options[:controller] = "#{options[:path_prefix]}/#{options[:controller]}"
          options.delete(:path_prefix)
          options.delete(:name_prefix)
          options.delete(:namespace)
        end

        requirements = (options.delete(:requirements) || {}).dup
        defaults     = (options.delete(:defaults)     || {}).dup
        conditions   = (options.delete(:conditions)   || {}).dup

        path_keys = segments.collect { |segment| segment.key if segment.respond_to?(:key) }.compact
        options.each do |key, value|
          hash = (path_keys.include?(key) && ! value.is_a?(Regexp)) ? defaults : requirements
          hash[key] = value
        end

        [defaults, requirements, conditions]
      end

      # Takes a hash of defaults and a hash of requirements, and assigns them to
      # the segments. Any unused requirements (which do not correspond to a segment)
      # are returned as a hash.
      def assign_route_options(segments, defaults, requirements)
        route_requirements = {} # Requirements that do not belong to a segment

        segment_named = Proc.new do |key|
          segments.detect { |segment| segment.key == key if segment.respond_to?(:key) }
        end

        requirements.each do |key, requirement|
          segment = segment_named[key]
          if segment
            raise TypeError, "#{key}: requirements on a path segment must be regular expressions" unless requirement.is_a?(Regexp)
            if requirement.source =~ %r{\A(\\A|\^)|(\\Z|\\z|\$)\Z}
              raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
            end
            segment.regexp = requirement
          else
            route_requirements[key] = requirement
          end
        end

        defaults.each do |key, default|
          segment = segment_named[key]
          raise ArgumentError, "#{key}: No matching segment exists; cannot assign default" unless segment
          segment.is_optional = true
          segment.default = default.to_param if default
        end

        assign_default_route_options(segments)
        ensure_required_segments(segments)
        route_requirements
      end

      # Assign default options, such as 'index' as a default for :action. This
      # method must be run *after* user supplied requirements and defaults have
      # been applied to the segments.
      def assign_default_route_options(segments)
        segments.each do |segment|
          next unless segment.is_a? DynamicSegment
          case segment.key
            when :action
              if segment.regexp.nil? || segment.regexp.match('index').to_s == 'index'
                segment.default ||= 'index'
                segment.is_optional = true
              end
            when :id
              if segment.default.nil? && segment.regexp.nil? || segment.regexp =~ ''
                segment.is_optional = true
              end
          end
        end
      end

      # Makes sure that there are no optional segments that precede a required
      # segment. If any are found that precede a required segment, they are
      # made required.
      def ensure_required_segments(segments)
        allow_optional = true
        segments.reverse_each do |segment|
          allow_optional &&= segment.optional?
          if !allow_optional && segment.optional?
            unless segment.optionality_implied?
              warn "Route segment \"#{segment.to_s}\" cannot be optional because it precedes a required segment. This segment will be required."
            end
            segment.is_optional = false
          elsif allow_optional && segment.respond_to?(:default) && segment.default
            # if a segment has a default, then it is optional
            segment.is_optional = true
          end
        end
      end

      # Construct and return a route with the given path and options.
      def build(path, options)
        # Wrap the path with slashes
        path = "/#{path}" unless path[0] == ?/
        path = "#{path}/" unless path[-1] == ?/

        path = "/#{options[:path_prefix].to_s.gsub(/^\//,'')}#{path}" if options[:path_prefix]

        segments = segments_for_route_path(path)
        defaults, requirements, conditions = divide_route_options(segments, options)
        requirements = assign_route_options(segments, defaults, requirements)

        route = Route.new

        route.segments = segments
        route.requirements = requirements
        route.conditions = conditions

        if !route.significant_keys.include?(:action) && !route.requirements[:action]
          route.requirements[:action] = "index"
          route.significant_keys << :action
        end

        # Routes cannot use the current string interpolation method
        # if there are user-supplied :requirements as the interpolation
        # code won't raise RoutingErrors when generating
        if options.key?(:requirements) || route.requirements.keys.to_set != Routing::ALLOWED_REQUIREMENTS_FOR_OPTIMISATION
          route.optimise = false
        end

        if !route.significant_keys.include?(:controller)
          raise ArgumentError, "Illegal route: the :controller must be specified!"
        end

        route
      end
    end
  end
end