爲什麼Rails4放棄了對Gemfile中“assets”組的支持 - Why did Rails4 drop support for “assets” group in the Gemfile

問題：

In Rails 3, gems used exclusively to generate assets in the asset pipeline were properly placed in the assets group of the Gemfile: 在Rails 3中，專門用於在資產管道中生成資產的gem被正確放置在Gemfile的assets組中：

...

# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails'
  gem 'coffee-rails'
  gem 'uglifier'

  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  # gem 'therubyracer', :platforms => :ruby
end

Now, according to the (still in progress) upgrade documentation : 現在，根據（仍在進行中） 升級文檔 ：

Rails 4.0 removed the assets group from Gemfile. Rails 4.0從Gemfile中刪除了資產組。 You'd need to remove that line from your Gemfile when upgrading. 升級時，您需要從Gemfile中刪除該行。

Sure enough, making a new project with RC1 yields a Gemfile with asset-related gems included by default outside of any group: 果然，使用RC1創建一個新項目會產生一個Gemfile，其默認包含在任何組之外的與資產相關的gems：

source 'https://rubygems.org'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.0.0.rc1'

# Use sqlite3 as the database for Active Record
gem 'sqlite3'

# Use SCSS for stylesheets
gem 'sass-rails', '~> 4.0.0.rc1'

# Use Uglifier as compressor for JavaScript assets
gem 'uglifier', '>= 1.3.0'

# Use CoffeeScript for .js.coffee assets and views
gem 'coffee-rails', '~> 4.0.0'

# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', platforms: :ruby

...

Does this mean these gems will now be bundled in production builds by default? 這是否意味着這些寶石現在默認捆綁在生產版本中？ If so, why the change of heart? 如果是這樣，爲什麼改變心意？ Is Rails 4 moving towards the dynamic generation of assets in production? Rails 4是否正朝着生產中動態生成資產的方向發展？

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解決方案：

參考： https://stackoom.com/en/question/16q0C