parameters.rb

# frozen_string_literal: true

# :markup: markdown

module ActionDispatch
  module Http
    module Parameters
      extend ActiveSupport::Concern

      PARAMETERS_KEY = "action_dispatch.request.path_parameters"

      DEFAULT_PARSERS = {
        Mime[:json].symbol => -> (raw_post) {
          data = ActiveSupport::JSON.decode(raw_post)
          data.is_a?(Hash) ? data : { _json: data }
        }
      }

      # Raised when raw data from the request cannot be parsed by the parser defined
      # for request's content MIME type.
      class ParseError < StandardError
        def initialize(message = $!.message)
          super(message)
        end
      end

      included do
        class << self
          # Returns the parameter parsers.
          attr_reader :parameter_parsers
        end

        self.parameter_parsers = DEFAULT_PARSERS
      end

      module ClassMethods
        # Configure the parameter parser for a given MIME type.
        #
        # It accepts a hash where the key is the symbol of the MIME type and the value
        # is a proc.
        #
        #     original_parsers = ActionDispatch::Request.parameter_parsers
        #     xml_parser = -> (raw_post) { Hash.from_xml(raw_post) || {} }
        #     new_parsers = original_parsers.merge(xml: xml_parser)
        #     ActionDispatch::Request.parameter_parsers = new_parsers
        def parameter_parsers=(parsers)
          @parameter_parsers = parsers.transform_keys { |key| key.respond_to?(:symbol) ? key.symbol : key }
        end
      end

      # Returns both GET and POST parameters in a single hash.
      def parameters
        params = get_header("action_dispatch.request.parameters")
        return params if params

        params = begin
                   request_parameters.merge(query_parameters)
                 rescue EOFError
                   query_parameters.dup
                 end
        params.merge!(path_parameters)
        set_header("action_dispatch.request.parameters", params)
        params
      end
      alias :params :parameters

      def path_parameters=(parameters) # :nodoc:
        @env.delete("action_dispatch.request.parameters")

        parameters = Request::Utils.set_binary_encoding(self, parameters, parameters[:controller], parameters[:action])
        # If any of the path parameters has an invalid encoding then raise since it's
        # likely to trigger errors further on.
        Request::Utils.check_param_encoding(parameters)

        @env[PARAMETERS_KEY] = parameters
      rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
        raise ActionController::BadRequest.new("Invalid path parameters: #{e.message}")
      end

      # Returns a hash with the parameters used to form the path of the request.
      # Returned hash keys are symbols:
      #
      #     { action: "my_action", controller: "my_controller" }
      def path_parameters
        @env[PARAMETERS_KEY] ||= {}
      end

      private
        def parse_formatted_parameters(parsers)
          return yield if content_length.zero? || content_mime_type.nil?

          strategy = parsers.fetch(content_mime_type.symbol) { return yield }

          begin
            strategy.call(raw_post)
          rescue # JSON or Ruby code block errors.
            log_parse_error_once
            raise ParseError, "Error occurred while parsing request parameters"
          end
        end

        def log_parse_error_once
          @parse_error_logged ||= begin
            parse_logger = logger || ActiveSupport::Logger.new($stderr)
            parse_logger.debug <<~MSG.chomp
              Error occurred while parsing request parameters.
              Contents:

              #{raw_post}
            MSG
          end
        end

        def params_parsers
          ActionDispatch::Request.parameter_parsers
        end
    end
  end
end