added registry module, where one can register by a tag; introducing transcoder, modules which can encode and decode; using them for the body/form/json bodies

lib/httpx.rb

@@ -1,8 +1,11 @@
 # frozen_string_literal: true
 
-
 require "httpx/version"
+
+require "httpx/errors"
 require "httpx/callbacks"
+require "httpx/registry"
+require "httpx/transcoder"
 require "httpx/options"
 require "httpx/timeout"
 require "httpx/connection"

lib/httpx/registry.rb

@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+module HTTPX
+  # Adds a general-purpose registry API to a class. It is designed to be a
+  # configuration-level API, i.e. the registry is global to the class and
+  # should be set on **boot time**.
+  #
+  # It is used internally to associate tags with handlers.
+  #
+  # ## Register/Fetch
+  #
+  # One is strongly advised to register handlers when creating the class.
+  #
+  # There is an instance-level method to retrieve from the registry based
+  # on the tag:
+  #
+  #     class Server
+  #       include HTTPX::Registry
+  #
+  #       register "tcp", TCPHandler
+  #       register "ssl", SSLHandlers
+  #       ...
+  #
+  #
+  #       def handle(uri)
+  #         scheme = uri.scheme
+  #         handler = registry(scheme) #=> TCPHandler
+  #         handler.handle
+  #       end
+  #     end
+  #
+  module Registry
+    # Base Registry Error
+    Error = Class.new(Error)
+
+    def self.extended(klass)
+      super
+      klass.extend(ClassMethods)
+    end
+
+    def self.included(klass)
+      super
+      klass.extend(ClassMethods)
+      klass.__send__(:include, InstanceMethods)
+    end
+
+    # Class Methods
+    module ClassMethods
+      # @param [Object] tag the handler identifier in the registry
+      # @return [Symbol, String, Object] the corresponding handler (if Symbol or String,
+      #   will assume it referes to an autoloaded module, and will load-and-return it).
+      #
+      def registry(tag = nil)
+        @registry ||= {}
+        return @registry if tag.nil?
+        handler = @registry.fetch(tag)
+        raise(Error, "#{tag} is not registered in #{self}") unless handler
+        case handler
+        when Symbol, String
+          const_get(handler)
+        else
+          handler
+        end
+      end
+
+      # @param [Object] tag the identifier for the handler in the registry
+      # @return [Symbol, String, Object] the handler (if Symbol or String, it is
+      #   assumed to be an autoloaded module, to be loaded later)
+      #
+      def register(tag, handler)
+        registry[tag] = handler
+      end
+    end
+
+    # Instance Methods
+    module InstanceMethods
+      # delegates to HTTPX::Registry#registry
+      def registry(tag)
+        self.class.registry(tag)
+      end
+    end
+  end
+end
+

lib/httpx/request.rb

@@ -1,8 +1,5 @@
 # frozen_string_literal: true
 
-require "http/form_data"
-require "json"
-
 module HTTPX
   class Request
     METHODS = [
@@ -72,18 +69,14 @@ module HTTPX
         @headers = headers
         @body = case
         when options.body
-          options.body
+          Transcoder.registry("body").encode(options.body)
         when options.form
-          form = HTTP::FormData.create(options.form)
-          @headers["content-type"] = form.content_type
-          @headers["content-length"] = form.content_length
-          form
+          Transcoder.registry("form").encode(options.form)
         when options.json
-          body = JSON.dump(options.json)
-          @headers["content-type"] = "application/json; charset=#{body.encoding.name.downcase}"
-          @headers["content-length"] = body.bytesize 
-          body 
+          Transcoder.registry("json").encode(options.json)
         end
+        @headers["content-type"] ||= @body.content_type
+        @headers["content-length"] ||= @body.content_length
       end
 
       def each(&block)

lib/httpx/transcoder.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module HTTPX
+  module Transcoder
+    extend Registry
+  end
+end
+
+require "httpx/transcoder/body"
+require "httpx/transcoder/form"
+require "httpx/transcoder/json"

lib/httpx/transcoder/body.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module HTTPX::Transcoder
+  module Body
+    module_function
+
+    class Encoder
+      def initialize(body)
+        @raw = body
+      end
+
+      def to_str
+        @raw
+      end
+
+      def content_length
+        if @raw.respond_to?(:bytesize)
+          @raw.bytesize
+        elsif @raw.respond_to?(:size)
+          @raw.size
+        else
+          raise Error, "cannot determine size of body: #{@raw.inspect}"
+        end
+      end
+
+      def content_type
+        "application/octet-stream"
+      end
+    end
+
+    def encode(body)
+      Encoder.new(body)
+    end
+  end
+  register "body", Body 
+end

lib/httpx/transcoder/form.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "http/form_data"
+
+module HTTPX::Transcoder
+  module Form
+    module_function
+
+    def encode(form)
+      HTTP::FormData.create(form)
+    end
+  end
+  register "form", Form
+end

lib/httpx/transcoder/json.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "json"
+
+module HTTPX::Transcoder
+  module JSON
+    module_function
+
+    class Encoder
+      def initialize(json)
+        @raw = ::JSON.dump(json)
+        @charset = @raw.encoding.name.downcase
+      end
+
+      def content_type
+        "application/json; charset=#{@charset}"
+      end
+
+      def content_length
+        @raw.bytesize
+      end
+
+      def to_str
+        @raw
+      end
+    end
+
+    def encode(json)
+      Encoder.new(json)
+    end
+  end
+  register "json", JSON 
+end