vendor/rails/actionpack/lib/action_controller/routing/route.rb

   1 module ActionController
   2   module Routing
   3     class Route #:nodoc:
   4       attr_accessor :segments, :requirements, :conditions, :optimise
   5
   6       def initialize(segments = [], requirements = {}, conditions = {})
   7         @segments = segments
   8         @requirements = requirements
   9         @conditions = conditions
  10
  11         if !significant_keys.include?(:action) && !requirements[:action]
  12           @requirements[:action] = "index"
  13           @significant_keys << :action
  14         end
  15
  16         # Routes cannot use the current string interpolation method
  17         # if there are user-supplied <tt>:requirements</tt> as the interpolation
  18         # code won't raise RoutingErrors when generating
  19         has_requirements = @segments.detect { |segment| segment.respond_to?(:regexp) && segment.regexp }
  20         if has_requirements || @requirements.keys.to_set != Routing::ALLOWED_REQUIREMENTS_FOR_OPTIMISATION
  21           @optimise = false
  22         else
  23           @optimise = true
  24         end
  25       end
  26
  27       # Indicates whether the routes should be optimised with the string interpolation
  28       # version of the named routes methods.
  29       def optimise?
  30         @optimise && ActionController::Base::optimise_named_routes
  31       end
  32
  33       def segment_keys
  34         segments.collect do |segment|
  35           segment.key if segment.respond_to? :key
  36         end.compact
  37       end
  38
  39       # Build a query string from the keys of the given hash. If +only_keys+
  40       # is given (as an array), only the keys indicated will be used to build
  41       # the query string. The query string will correctly build array parameter
  42       # values.
  43       def build_query_string(hash, only_keys = nil)
  44         elements = []
  45
  46         (only_keys || hash.keys).each do |key|
  47           if value = hash[key]
  48             elements << value.to_query(key)
  49           end
  50         end
  51
  52         elements.empty? ? '' : "?#{elements.sort * '&'}"
  53       end
  54
  55       # A route's parameter shell contains parameter values that are not in the
  56       # route's path, but should be placed in the recognized hash.
  57       #
  58       # For example, +{:controller => 'pages', :action => 'show'} is the shell for the route:
  59       #
  60       #   map.connect '/page/:id', :controller => 'pages', :action => 'show', :id => /\d+/
  61       #
  62       def parameter_shell
  63         @parameter_shell ||= returning({}) do |shell|
  64           requirements.each do |key, requirement|
  65             shell[key] = requirement unless requirement.is_a? Regexp
  66           end
  67         end
  68       end
  69
  70       # Return an array containing all the keys that are used in this route. This
  71       # includes keys that appear inside the path, and keys that have requirements
  72       # placed upon them.
  73       def significant_keys
  74         @significant_keys ||= returning([]) do |sk|
  75           segments.each { |segment| sk << segment.key if segment.respond_to? :key }
  76           sk.concat requirements.keys
  77           sk.uniq!
  78         end
  79       end
  80
  81       # Return a hash of key/value pairs representing the keys in the route that
  82       # have defaults, or which are specified by non-regexp requirements.
  83       def defaults
  84         @defaults ||= returning({}) do |hash|
  85           segments.each do |segment|
  86             next unless segment.respond_to? :default
  87             hash[segment.key] = segment.default unless segment.default.nil?
  88           end
  89           requirements.each do |key,req|
  90             next if Regexp === req || req.nil?
  91             hash[key] = req
  92           end
  93         end
  94       end
  95
  96       def matches_controller_and_action?(controller, action)
  97         prepare_matching!
  98         (@controller_requirement.nil? || @controller_requirement === controller) &&
  99         (@action_requirement.nil? || @action_requirement === action)
 100       end
 101
 102       def to_s
 103         @to_s ||= begin
 104           segs = segments.inject("") { |str,s| str << s.to_s }
 105           "%-6s %-40s %s" % [(conditions[:method] || :any).to_s.upcase, segs, requirements.inspect]
 106         end
 107       end
 108
 109       # TODO: Route should be prepared and frozen on initialize
 110       def freeze
 111         unless frozen?
 112           write_generation!
 113           write_recognition!
 114           prepare_matching!
 115
 116           parameter_shell
 117           significant_keys
 118           defaults
 119           to_s
 120         end
 121
 122         super
 123       end
 124
 125       private
 126         def requirement_for(key)
 127           return requirements[key] if requirements.key? key
 128           segments.each do |segment|
 129             return segment.regexp if segment.respond_to?(:key) && segment.key == key
 130           end
 131           nil
 132         end
 133
 134         # Write and compile a +generate+ method for this Route.
 135         def write_generation!
 136           # Build the main body of the generation
 137           body = "expired = false\n#{generation_extraction}\n#{generation_structure}"
 138
 139           # If we have conditions that must be tested first, nest the body inside an if
 140           body = "if #{generation_requirements}\n#{body}\nend" if generation_requirements
 141           args = "options, hash, expire_on = {}"
 142
 143           # Nest the body inside of a def block, and then compile it.
 144           raw_method = method_decl = "def generate_raw(#{args})\npath = begin\n#{body}\nend\n[path, hash]\nend"
 145           instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
 146
 147           # expire_on.keys == recall.keys; in other words, the keys in the expire_on hash
 148           # are the same as the keys that were recalled from the previous request. Thus,
 149           # we can use the expire_on.keys to determine which keys ought to be used to build
 150           # the query string. (Never use keys from the recalled request when building the
 151           # query string.)
 152
 153           method_decl = "def generate(#{args})\npath, hash = generate_raw(options, hash, expire_on)\nappend_query_string(path, hash, extra_keys(options))\nend"
 154           instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
 155
 156           method_decl = "def generate_extras(#{args})\npath, hash = generate_raw(options, hash, expire_on)\n[path, extra_keys(options)]\nend"
 157           instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
 158           raw_method
 159         end
 160
 161         # Build several lines of code that extract values from the options hash. If any
 162         # of the values are missing or rejected then a return will be executed.
 163         def generation_extraction
 164           segments.collect do |segment|
 165             segment.extraction_code
 166           end.compact * "\n"
 167         end
 168
 169         # Produce a condition expression that will check the requirements of this route
 170         # upon generation.
 171         def generation_requirements
 172           requirement_conditions = requirements.collect do |key, req|
 173             if req.is_a? Regexp
 174               value_regexp = Regexp.new "\\A#{req.to_s}\\Z"
 175               "hash[:#{key}] && #{value_regexp.inspect} =~ options[:#{key}]"
 176             else
 177               "hash[:#{key}] == #{req.inspect}"
 178             end
 179           end
 180           requirement_conditions * ' && ' unless requirement_conditions.empty?
 181         end
 182
 183         def generation_structure
 184           segments.last.string_structure segments[0..-2]
 185         end
 186
 187         # Write and compile a +recognize+ method for this Route.
 188         def write_recognition!
 189           # Create an if structure to extract the params from a match if it occurs.
 190           body = "params = parameter_shell.dup\n#{recognition_extraction * "\n"}\nparams"
 191           body = "if #{recognition_conditions.join(" && ")}\n#{body}\nend"
 192
 193           # Build the method declaration and compile it
 194           method_decl = "def recognize(path, env = {})\n#{body}\nend"
 195           instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
 196           method_decl
 197         end
 198
 199         # Plugins may override this method to add other conditions, like checks on
 200         # host, subdomain, and so forth. Note that changes here only affect route
 201         # recognition, not generation.
 202         def recognition_conditions
 203           result = ["(match = #{Regexp.new(recognition_pattern).inspect}.match(path))"]
 204           result << "[conditions[:method]].flatten.include?(env[:method])" if conditions[:method]
 205           result
 206         end
 207
 208         # Build the regular expression pattern that will match this route.
 209         def recognition_pattern(wrap = true)
 210           pattern = ''
 211           segments.reverse_each do |segment|
 212             pattern = segment.build_pattern pattern
 213           end
 214           wrap ? ("\\A" + pattern + "\\Z") : pattern
 215         end
 216
 217         # Write the code to extract the parameters from a matched route.
 218         def recognition_extraction
 219           next_capture = 1
 220           extraction = segments.collect do |segment|
 221             x = segment.match_extraction(next_capture)
 222             next_capture += segment.number_of_captures
 223             x
 224           end
 225           extraction.compact
 226         end
 227
 228         # Generate the query string with any extra keys in the hash and append
 229         # it to the given path, returning the new path.
 230         def append_query_string(path, hash, query_keys = nil)
 231           return nil unless path
 232           query_keys ||= extra_keys(hash)
 233           "#{path}#{build_query_string(hash, query_keys)}"
 234         end
 235
 236         # Determine which keys in the given hash are "extra". Extra keys are
 237         # those that were not used to generate a particular route. The extra
 238         # keys also do not include those recalled from the prior request, nor
 239         # do they include any keys that were implied in the route (like a
 240         # <tt>:controller</tt> that is required, but not explicitly used in the
 241         # text of the route.)
 242         def extra_keys(hash, recall = {})
 243           (hash || {}).keys.map { |k| k.to_sym } - (recall || {}).keys - significant_keys
 244         end
 245
 246         def prepare_matching!
 247           unless defined? @matching_prepared
 248             @controller_requirement = requirement_for(:controller)
 249             @action_requirement = requirement_for(:action)
 250             @matching_prepared = true
 251           end
 252         end
 253     end
 254   end
 255 end