Riot.js/riot_js-railsの手直しの履歴(No.4)

更新

概要†

rails から riot.js を使うための gem として、 riot_js-rails というのがあるのですが、環境によってどうもうまく動かないように思えたため、手直しできないか調べてみました。

結果、どうにも手に負える物ではなかった感じです。。。

症状†

$ ruby --version
 ruby 1.9.3p551 (2014-11-13 revision 48407) [x86_64-linux]
$ rails new riot_js-rails_sample -B
$ cd riot_js-rails_sample/
$ jed Gemfile
 gem 'riot_js-rails'
$ bundle install
$ cat Gemfile.lock
 ...
 DEPENDENCIES
   coffee-rails (~> 4.0.0)
   jbuilder (~> 1.2)
   jquery-rails
   rails (= 4.0.13)
   riot_js-rails
   sass-rails (~> 4.0.2)
   sdoc
   sqlite3
   turbolinks
   uglifier (>= 1.3.0)

 BUNDLED WITH
    1.11.2
$ rails generate controller main index
       create  app/controllers/main_controller.rb
        route  get "main/index"
       invoke  erb
       create    app/views/main
       create    app/views/main/index.html.erb
       invoke  test_unit
       create    test/controllers/main_controller_test.rb
       invoke  helper
       create    app/helpers/main_helper.rb
       invoke    test_unit
       create      test/helpers/main_helper_test.rb
       invoke  assets
       invoke    coffee
       create      app/assets/javascripts/main.js.coffee
       invoke    scss
       create      app/assets/stylesheets/main.css.scss
$ jed config/routes.rb
    root 'main#index'
$ rails s &
$ wget -q -O - http://localhost:3000/
 ...
 <h1>Main#index</h1>
 <p>Find me in app/views/main/index.html.erb</p>
 ...
$ cat > app/assets/javascripts/test-tag.tag
 <test-tag>
   Ok!
 </test-tag>
$ jed app/assets/javascripts/application.js
+  //= require riot
+  //= require riot-rails
   //= require_tree .
$ wget -q -O - http://localhost:3000/
 <script data-turbolinks-track="true" src="/assets/riot.js?body=1"></script>
 <script data-turbolinks-track="true" src="/assets/riot_rails.js?body=1"></script>
 <script data-turbolinks-track="true" src="/assets/main.js?body=1"></script>
 <script data-turbolinks-track="true" src="/assets/application.js?body=1"></script>

require_tree で test-tag.tag が読み込まれていません。

$ mv app/assets/javascripts/test-tag.tag app/assets/javascripts/test-tag.js.tag
$ wget -q -O - http://localhost:3000/
 <script data-turbolinks-track="true" src="/assets/riot.js?body=1"></script>
 <script data-turbolinks-track="true" src="/assets/riot_rails.js?body=1"></script>
 <script data-turbolinks-track="true" src="/assets/main.js?body=1"></script>
 <script data-turbolinks-track="true" src="/javascripts/test-tag.js.tag.js"></script>
 <script data-turbolinks-track="true" src="/assets/application.js?body=1"></script>
$ wget -q -O - http://localhost:3000/javascripts/test-tag.js.tag.js
 Started GET "/javascripts/test-tag.js.tag.js" for 127.0.0.1 at 2016-07-01 13:55:32 +0900
 ActionController::RoutingError (No route matches [GET] "/javascripts/test-tag.js.tag.js"):
$ wget -q -O - http://localhost:3000/assets/test-tag.js.tag.js?body=1
 Started GET "/assets/test-tag.js.tag.js?body=1" for 127.0.0.1 at 2016-07-01 13:56:24 +0900
 ActionController::RoutingError (No route matches [GET] "/assets/test-tag.js.tag.js"):

test-tag.tag ではなく test-tag.js.tag としたところ、読み込もうとする姿勢は見られましたが、 /assets/ ではなく /javascripts/ が指定されており、なおかつ両方とも RoutingError になってしまいます。

Rails のバージョンを上げると†

$ rvm use ruby-2.2.1
$ ruby --version
 ruby 2.2.1p85 (2015-02-26 revision 49769) [x86_64-linux]
$ rails --version
 Rails 4.2.6
$ rails new riot_js-rails_sample -B
$ cd riot_js-rails_sample/
$ jed Gemfile
 gem 'riot_js-rails'
$ bundle install
$ cat Gemfile.lock
 DEPENDENCIES
   byebug
   coffee-rails (~> 4.1.0)
   jbuilder (~> 2.0)
   jquery-rails
   rails (= 4.2.6)
   riot_js-rails
   sass-rails (~> 5.0)
   sdoc (~> 0.4.0)
   spring
   sqlite3
   turbolinks
   uglifier (>= 1.3.0)
   web-console (~> 2.0)
$ echo "Sprockets::VERSION" | rails c
 Loading development environment (Rails 4.2.6)
 Switch to inspect mode.
 Sprockets::VERSION
 "3.6.3"

この環境だと、上と同じ操作で

 <script src="/assets/riot.self-d4789eae993b10e05f4694693fa33efe6afd5ccd866d3f6eee21de793efc7f31.js?body=1" data-turbolinks-track="true"></script>
 <script src="/assets/riot_rails.self-23d22569edc9e83fe5a74dbf647822c59a2fcd08777f496b38cab2507f2d594d.js?body=1" data-turbolinks-track="true"></script>
 <script src="/assets/main.self-877aef30ae1b040ab8a3aba4e3e309a11d7f2612f44dde450b5c157aa5f95c05.js?body=1" data-turbolinks-track="true"></script>
 <script src="/assets/test-tag.self-198db509a34ddfb1d978f239761117f57e5680e43ffe43f5524092ecb41ca2b3.js?body=1" data-turbolinks-track="true"></script>
 <script src="/assets/application.self-7862a8a8b42407b4741a1adeeea35f0d13ddc4f702ec532adb0674491d296495.js?body=1" data-turbolinks-track="true"></script>

のように、"test-tag.self-XXXX.js" が正しくコンパイルされます。

どうやら sprockets のバージョン依存・・・なのでしょうか？

ソースを確認†

$ cd ..
$ git clone https://github.com/bjarosze/riot_js-rails.git
 Cloning into 'riot_js-rails'...
 remote: Counting objects: 180, done.
 remote: Total 180 (delta 0), reused 0 (delta 0), pack-reused 180
 Receiving objects: 100% (180/180), 79.78 KiB | 90.00 KiB/s, done.
 Resolving deltas: 100% (61/61), done.
 Checking connectivity... done.
$ cd riot_js-rails
$ ls -a
 .  ..  .git  .gitignore  Gemfile  README.md  Rakefile  lib  riot_js-rails.gemspec  test  vendor
$ git branch -m fix-asset-path
$ git status
 On branch fix-asset-path
 Your branch is up-to-date with 'origin/master'.
 nothing to commit, working directory clean
$ cat lib/riot_js/rails/railtie.rb
 require 'rails/railtie'
 require 'riot_js/rails/processors/processor'
 require 'riot_js/rails/helper'
 
 module RiotJs
   module Rails
     class Railtie < ::Rails::Railtie
 
       initializer :setup_sprockets do |app|
         Processor.register_self config
         ...
$ cat lib/riot_js/rails/processors/processor.rb
 require 'riot_js/rails/processors/compiler'
 
 if Gem::Version.new(Sprockets::VERSION) < Gem::Version.new('3.0.0')
   require 'riot_js/rails/processors/sprockets_processor_v2'
 else
   require 'riot_js/rails/processors/sprockets_processor_v3'
 end
 
 module RiotJs
   module Rails
     class Processor < SprocketsProcessor
 
       def process
         compile_tag
       end
 
       private
 
       def compile_tag
         ::RiotJs::Rails::Compiler.compile(@data)
       end
     end
   end
 end
$ echo "Sprockets::VERSION" | rails c
 Loading development environment (Rails 4.0.13)
 Switch to inspect mode.
 Sprockets::VERSION
 "2.12.4"
$ cat lib/riot_js/rails/processors/sprockets_rocessor_v2.rb
 module RiotJs
   module Rails
     class SprocketsProcessor < Tilt::Template
 
       self.default_mime_type = 'application/javascript'
 
       def self.register_self(app)
         app.assets.register_engine '.tag', self
       end
 
       def evaluate(context, locals, &block)
         @context = context
         process
       end
 
       def prepare
         @data = data
       end
 
       def process
         raise 'Not implemented'
       end
 
     end
   end
 end

これを直すのは難しそうです。。。

coffee-rails のソースを見る†

特定の拡張子を持ったファイルを .js に変換するという動作は coffee-rails と同様なので、

https://github.com/rails/coffee-rails/

これと同じことをやれば良いはずなのですが、、、

.coffee から .js へのコンパイル部分は

https://github.com/rails/coffee-rails/blob/master/lib/coffee/rails/template_handler.rb

LANG:ruby
module Coffee
  module Rails
    class TemplateHandler
      def self.erb_handler
        @@erb_handler ||= ActionView::Template.registered_template_handler(:erb)
      end

      def self.call(template)
        compiled_source = erb_handler.call(template)
        "CoffeeScript.compile(begin;#{compiled_source};end)"
      end
    end
  end
end

ActiveSupport.on_load(:action_view) do
  ActionView::Template.register_template_handler :coffee, Coffee::Rails::TemplateHandler
end

だけだと思われて、なおかつこの部分は上記前者で読まれた v4.0.1 でも、後者で読まれた v4.1.1 でも変更されていないにも関わらず、同じことをしてみても、どうもうまくいかず、困ってしまいます。

coffee-rails のまねをする†

$ git clone https://github.com/rails/coffee-rails.git
$ mv coffee-rails/ riottag-rails
$ (いろいろ直す)

主には、

LANG:ruby
module RiotTag
  module Rails
    class TemplateHandler
      def self.erb_handler
        @@erb_handler ||= ActionView::Template.registered_template_handler(:erb)
      end

      def self.call(template)
        compiled_source = erb_handler.call(template)
        "'Compiled!'.html_safe"
      end
    end
  end
end

ActiveSupport.on_load(:action_view) do
  ActionView::Template.register_template_handler :tag, RiotTag::Rails::TemplateHandler
end

全然うまくいきません（涙

というか、coffee-rails の該当部分 ActionView::Template.register_template_handler をコメントアウトしても coffee-rails が動き続けているあたり、見ている場所が全然違うのかもしれません？！

素直に rails のバージョンを上げることを考えるべきなのかも・・・

それにしても黒魔術すぎて、キビシイなあ

それっぽい記事を発見（未検証）†

Supporting All Versions of Sprockets in Processors
https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors

これによると、

class SprocketsExtensionBase
  def initialize(filename, &block)
    @filename = filename
    @source   = block.call
  end

  def render(context, empty_hash_wtf)
    self.class.run(@filename, @source, context)
  end

  def self.run(filename, source, context)
    /* return the modified source */
  end

  def self.call(input)
    filename = input[:filename]
    source   = input[:data]
    context  = input[:environment].context_class.new(input)
 
    result = run(filename, source, context)
    context.metadata.merge(data: result)
  end
end

を継承して run を override すれば Extention を作れる。

　require 'sprockets/processing' 　extend Sprockets::Processing 　　register_preprocessor 'text/css', TheSprocketsExtension

で拡張機能を登録して、

def register_sprockets_extention(env, mime_type, file_ext, charset, sprockets_extention)
  file_ext = [file_ext] unless file_ext.instance_of?(Array)
  charset = charset.to_sym
 
  # Sprockets 2, 3, and 4
  
  if env.respond_to?(:register_transformer)
    env.register_mime_type mime_type, extensions: file_ext, charset: charset
    env.register_preprocessor mime_type, sprockets_extention
  end
  
  if env.respond_to?(:register_engine)
    args = [file_ext, sprockets_extention]
    args << { mime_type: mime_type, silence_deprecation: true } if Sprockets::VERSION.start_with?("3")
    env.register_engine(*args)
  end
end

これで良さそう？

あら、ものすごく重要なことがさらっと書いてあった。

prockets 4 will not chain asset extensions so .coffee.erb is explicitly registered in addition to .coffee. If your application introduces a new mime/extension combo it will be responsible for registering all combinations.

だから file.tag.haml が動かなかったのか。。。

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