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-rw-r--r-- | guides/source/engines.md | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/guides/source/engines.md b/guides/source/engines.md index f961b799f1..7f6021a5eb 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -239,6 +239,24 @@ NOTE: The `ApplicationController` class inside an engine is named just like a Rails application in order to make it easier for you to convert your applications into engines. +WARNING: Due to the way Rails autoloads controllers, it could happen that the main +application's `ApplicationController` were loaded before the engine's `ApplicationController`. +In such case, the Ruby interpreter would not load the latter class and your engine's +controllers would miss methods defined in it (because they would inherit from main +`ApplicationController`. For this reason the code in engine's controllers must explicitly +tell Ruby they depend on the right application controller. This can be achieved with +a single line at the top of the controllers files. For example: + +```ruby +# articles_controller.rb: +require_dependency "blorgh/application_controller" # Explicit dependency required! +module Blorgh + class ArticlesController < ApplicationController + ... + end +end +``` + Lastly, the `app/views` directory contains a `layouts` folder, which contains a file at `blorgh/application.html.erb`. This file allows you to specify a layout for the engine. If this engine is to be used as a stand-alone engine, then you |