require 'action_dispatch/http/request' module ActionDispatch # ActionDispatch::ParamsParser works for all the requests having any Content-Length # (like POST). It takes raw data from the request and puts it through the parser # that is picked based on Content-Type header. # # In case of any error while parsing data ParamsParser::ParseError is raised. class ParamsParser # Raised when raw data from the request cannot be parsed by the parser # defined for request's content mime type. class ParseError < StandardError attr_reader :original_exception def initialize(message, original_exception) super(message) @original_exception = original_exception end end DEFAULT_PARSERS = { Mime::JSON => lambda { |raw_post| data = ActiveSupport::JSON.decode(raw_post) data = {:_json => data} unless data.is_a?(Hash) Request::Utils.normalize_encode_params(data) } } # Create a new +ParamsParser+ middleware instance. # # The +parsers+ argument can take Hash of parsers where key is identifying # content mime type, and value is a lambda that is going to process data. def initialize(app, parsers = {}) @app, @parsers = app, DEFAULT_PARSERS.merge(parsers) end def call(env) request = Request.new(env) parse_formatted_parameters(request, @parsers) do |params| request.request_parameters = params end @app.call(env) end private def parse_formatted_parameters(request, parsers) return if request.content_length.zero? strategy = parsers.fetch(request.content_mime_type) { return nil } yield strategy.call(request.raw_post) rescue => e # JSON or Ruby code block errors logger(request).debug "Error occurred while parsing request parameters.\nContents:\n\n#{request.raw_post}" raise ParseError.new(e.message, e) end def logger(request) request.logger || ActiveSupport::Logger.new($stderr) end end end