Merge pull request #253 from rmosolgo/decouple-renderer

Decouple renderer

Author: Robert Mosolgo

Guardfile

@@ -0,0 +1,6 @@
+guard :minitest do
+  # with Minitest::Unit
+  watch(%r{^test/(.*)\/?(.*)_test\.rb$})
+  watch(%r{^lib/(.*/)?([^/]+)\.rb$})     { |m| "test/#{m[1]}#{m[2]}_test.rb" }
+  watch(%r{^test/test_helper\.rb$})      { 'test' }
+end

README.md

@@ -154,18 +154,14 @@ You can configure your pool of JS virtual machines and specify where it should l
 # config/environments/application.rb
 # These are the defaults if you dont specify any yourself
 MyApp::Application.configure do
-  # renderer pool size:
-  config.react.max_renderers = 10
-  # prerender timeout, in seconds:
-  config.react.timeout = 20
-  # where to get React.js source:
-  config.react.react_js = lambda { File.read(::Rails.application.assets.resolve('react.js')) }
-  # array of filenames that will be requested from the asset pipeline
-  # and concatenated:
-  config.react.component_filenames = ['components.js']
-  # server-side console.log, console.warn, and console.error messages will be replayed on the client
-  # (you can set this to `true` in config/enviroments/development.rb to replay in development only)
-  config.react.replay_console = false
+  # Settings for the pool of renderers:
+  config.react.server_renderer_pool_size  ||= 10
+  config.react.server_renderer_timeout    ||= 20 # seconds
+  config.react.server_renderer = React::ServerRendering::SprocketsRenderer
+  config.react.server_renderer_options = {
+    files: ["react.js", "components.js"], # files to load for prerendering
+    replay_console: true,                 # if true, console.* will be replayed client-side
+  }
 end
 ```
 

lib/react-rails.rb

@@ -1,5 +1,4 @@
 require 'react/jsx'
-require 'react/renderer'
 require 'react/rails'
-require 'react/console'
+require 'react/server_rendering'
 

lib/react/console.rb

@@ -9,11 +9,11 @@ class Railtie < ::Rails::Railtie
       config.react.variant = (::Rails.env.production? ? :production : :development)
       config.react.addons = false
       config.react.jsx_transform_options = {}
-      # Server-side rendering
-      config.react.max_renderers = 10
-      config.react.timeout = 20 #seconds
-      config.react.react_js = lambda {File.read(::Rails.application.assets.resolve('react.js'))}
-      config.react.component_filenames = ['components.js']
+      # Server rendering:
+      config.react.server_renderer_pool_size  = 10
+      config.react.server_renderer_timeout    = 20 # seconds
+      config.react.server_renderer            = nil # defaults to SprocketsRenderer
+      config.react.server_renderer_options    = {}  # SprocketsRenderer provides defaults
 
       # Watch .jsx files for changes in dev, so we can reload the JS VMs with the new JS code.
       initializer "react_rails.add_watchable_files", group: :all do |app|
@@ -49,24 +49,17 @@ class Railtie < ::Rails::Railtie
           "react-#{variant}",
         ].compact.join('-')
 
-        # Server Rendering
-        # Concat component_filenames together for server rendering
-        app.config.react.components_js = lambda {
-          app.config.react.component_filenames.map do |filename|
-            app.assets[filename].to_s
-          end.join(";")
-        }
+        # The class isn't accessible in the configure block, so assign it here if it wasn't overridden:
+        app.config.react.server_renderer ||= React::ServerRendering::SprocketsRenderer
 
-        do_setup = lambda do
-          cfg = app.config.react
-          React::Renderer.setup!( cfg.react_js, cfg.components_js, cfg.replay_console,
-                                {:size => cfg.max_renderers, :timeout => cfg.timeout})
-        end
-
-        do_setup.call
+        React::ServerRendering.pool_size        = app.config.react.server_renderer_pool_size
+        React::ServerRendering.pool_timeout     = app.config.react.server_renderer_timeout
+        React::ServerRendering.renderer_options = app.config.react.server_renderer_options
+        React::ServerRendering.renderer         = app.config.react.server_renderer
 
-        # Reload the JS VMs in dev when files change
-        ActionDispatch::Reloader.to_prepare(&do_setup)
+        React::ServerRendering.reset_pool
+        # Reload renderers in dev when files change
+        ActionDispatch::Reloader.to_prepare { React::ServerRendering.reset_pool }
       end
     end
   end

lib/react/rails/railtie.rb

@@ -1,28 +1,29 @@
 module React
   module Rails
     module ViewHelper
-
       # Render a UJS-type HTML tag annotated with data attributes, which
       # are used by react_ujs to actually instantiate the React component
       # on the client.
-      #
-      def react_component(name, args = {}, options = {}, &block)
+      def react_component(name, props = {}, options = {}, &block)
         options = {:tag => options} if options.is_a?(Symbol)
-        block = Proc.new{concat React::Renderer.render(name, args)} if options[:prerender]
+
+        prerender_options = options[:prerender]
+        if prerender_options
+          block = Proc.new{ concat React::ServerRendering.render(name, props.merge(prerender: prerender_options)) }
+        end
 
         html_options = options.reverse_merge(:data => {})
         html_options[:data].tap do |data|
           data[:react_class] = name
-          data[:react_props] = React::Renderer.react_props(args) unless args.empty?
+          data[:react_props] = (props.is_a?(String) ? props : props.to_json)
         end
         html_tag = html_options[:tag] || :div
-        
+
         # remove internally used properties so they aren't rendered to DOM
         html_options.except!(:tag, :prerender)
-        
+
         content_tag(html_tag, '', html_options, &block)
       end
-
     end
   end
 end

lib/react/rails/view_helper.rb

@@ -0,0 +1,24 @@
+require 'connection_pool'
+require 'react/server_rendering/sprockets_renderer'
+
+module React
+  module ServerRendering
+    mattr_accessor :renderer, :renderer_options,
+      :pool_size, :pool_timeout
+
+    def self.reset_pool
+      options = {size: pool_size, timeout: pool_timeout}
+      @@pool = ConnectionPool.new(options) { create_renderer }
+    end
+
+    def self.render(component_name, props)
+      @@pool.with do |renderer|
+        renderer.render(component_name, props)
+      end
+    end
+
+    def self.create_renderer
+      renderer.new(renderer_options)
+    end
+  end
+end

lib/react/renderer.rb

@@ -0,0 +1,81 @@
+module React
+  module ServerRendering
+    class SprocketsRenderer
+      def initialize(options={})
+        @replay_console = options.fetch(:replay_console, true)
+
+        filenames = options.fetch(:files, ["react.js", "components.js"])
+        js_code = GLOBAL_WRAPPER + CONSOLE_POLYFILL
+
+        filenames.each do |filename|
+          js_code << ::Rails.application.assets[filename].to_s
+        end
+
+        @context = ExecJS.compile(js_code)
+      end
+
+      def render(component_name, props)
+        # pass prerender: :static to use renderToStaticMarkup
+        if props.is_a?(Hash) && props[:prerender] == :static
+          react_render_method = "renderToStaticMarkup"
+        else
+          react_render_method = "renderToString"
+        end
+
+        if !props.is_a?(String)
+          props = props.to_json
+        end
+
+        js_code = <<-JS
+          (function () {
+            var result = React.#{react_render_method}(React.createElement(#{component_name}, #{props}));
+            #{@replay_console ? CONSOLE_REPLAY : ""}
+            return result;
+          })()
+        JS
+
+        @context.eval(js_code).html_safe
+      rescue ExecJS::ProgramError => err
+        raise PrerenderError.new(component_name, props, err)
+      end
+
+      # Handle node.js & other RubyRacer contexts
+      GLOBAL_WRAPPER = <<-JS
+      var global = global || this;
+      var self = self || this;
+      var window = window || this;
+      JS
+
+      # Reimplement console methods for replaying on the client
+      CONSOLE_POLYFILL = <<-JS
+        var console = { history: [] };
+        ['error', 'log', 'info', 'warn'].forEach(function (fn) {
+          console[fn] = function () {
+            console.history.push({level: fn, arguments: Array.prototype.slice.call(arguments)});
+          };
+        });
+      JS
+
+      # Replay message from console history
+      CONSOLE_REPLAY = <<-JS
+      (function (history) {
+        if (history && history.length > 0) {
+          result += '\\n<scr'+'ipt>';
+          history.forEach(function (msg) {
+            result += '\\nconsole.' + msg.level + '.apply(console, ' + JSON.stringify(msg.arguments) + ');';
+          });
+          result += '\\n</scr'+'ipt>';
+        }
+      })(console.history);
+      JS
+
+      class PrerenderError < RuntimeError
+        def initialize(component_name, props, js_message)
+          message = ["Encountered error \"#{js_message}\" when prerendering #{component_name} with #{props}",
+                      js_message.backtrace.join("\n")].join("\n")
+          super(message)
+        end
+      end
+    end
+  end
+end

lib/react/server_rendering.rb

@@ -18,6 +18,8 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'bundler', '>= 1.2.2'
   s.add_development_dependency 'coffee-rails'
   s.add_development_dependency 'es5-shim-rails', '>= 2.0.5'
+  s.add_development_dependency 'guard'
+  s.add_development_dependency 'guard-minitest'
   s.add_development_dependency 'jbuilder'
   s.add_development_dependency 'poltergeist', '>= 0.3.3'
   s.add_development_dependency 'test-unit', '~> 2.5'