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Diffstat (limited to 'guides/source/engines.md')
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diff --git a/guides/source/engines.md b/guides/source/engines.md index 8d81296fa5..1e93a19c84 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON https://guides.rubyonrails.org.** Getting Started with Engines ============================ @@ -188,7 +188,7 @@ inside the application, performing tasks such as adding the `app` directory of the engine to the load path for models, mailers, controllers, and views. The `isolate_namespace` method here deserves special notice. This call is -responsible for isolating the controllers, models, routes and other things into +responsible for isolating the controllers, models, routes, and other things into their own namespace, away from similar components inside the application. Without this, there is a possibility that the engine's components could "leak" into the application, causing unwanted disruption, or that important engine @@ -202,7 +202,7 @@ within the `Engine` class definition. Without it, classes generated in an engine **may** conflict with an application. What this isolation of the namespace means is that a model generated by a call -to `bin/rails g model`, such as `bin/rails g model article`, won't be called `Article`, but +to `rails g model`, such as `rails g model article`, won't be called `Article`, but instead be namespaced and called `Blorgh::Article`. In addition, the table for the model is namespaced, becoming `blorgh_articles`, rather than simply `articles`. Similar to the model namespacing, a controller called `ArticlesController` becomes @@ -313,13 +313,16 @@ The engine that this guide covers provides submitting articles and commenting functionality and follows a similar thread to the [Getting Started Guide](getting_started.html), with some new twists. +NOTE: For this section, make sure to run the commands in the root of the +`blorgh` engine's directory. + ### Generating an Article Resource The first thing to generate for a blog engine is the `Article` model and related controller. To quickly generate this, you can use the Rails scaffold generator. ```bash -$ bin/rails generate scaffold article title:string text:text +$ rails generate scaffold article title:string text:text ``` This command will output this information: @@ -427,7 +430,7 @@ Finally, the assets for this resource are generated in two files: `app/assets/stylesheets/blorgh/articles.css`. You'll see how to use these a little later. -You can see what the engine has so far by running `bin/rails db:migrate` at the root +You can see what the engine has so far by running `rails db:migrate` at the root of our engine to run the migration generated by the scaffold generator, and then running `rails server` in `test/dummy`. When you open `http://localhost:3000/blorgh/articles` you will see the default scaffold that has @@ -461,7 +464,7 @@ rather than visiting `/articles`. This means that instead of Now that the engine can create new articles, it only makes sense to add commenting functionality as well. To do this, you'll need to generate a comment -model, a comment controller and then modify the articles scaffold to display +model, a comment controller, and then modify the articles scaffold to display comments and allow people to create new ones. From the application root, run the model generator. Tell it to generate a @@ -469,7 +472,7 @@ From the application root, run the model generator. Tell it to generate a and `text` text column. ```bash -$ bin/rails generate model Comment article_id:integer text:text +$ rails generate model Comment article_id:integer text:text ``` This will output the following: @@ -489,7 +492,7 @@ called `Blorgh::Comment`. Now run the migration to create our blorgh_comments table: ```bash -$ bin/rails db:migrate +$ rails db:migrate ``` To show the comments on an article, edit `app/views/blorgh/articles/show.html.erb` and @@ -563,7 +566,7 @@ The route now exists, but the controller that this route goes to does not. To create it, run this command from the application root: ```bash -$ bin/rails g controller comments +$ rails g controller comments ``` This will generate the following things: @@ -695,17 +698,17 @@ pre-defined path which may be customizable. The engine contains migrations for the `blorgh_articles` and `blorgh_comments` table which need to be created in the application's database so that the engine's models can query them correctly. To copy these migrations into the -application run the following command from the `test/dummy` directory of your Rails engine: +application run the following command from the application's root: ```bash -$ bin/rails blorgh:install:migrations +$ rails blorgh:install:migrations ``` If you have multiple engines that need migrations copied over, use `railties:install:migrations` instead: ```bash -$ bin/rails railties:install:migrations +$ rails railties:install:migrations ``` This command, when run for the first time, will copy over all the migrations @@ -723,7 +726,7 @@ timestamp (`[timestamp_2]`) will be the current time plus a second. The reason for this is so that the migrations for the engine are run after any existing migrations in the application. -To run these migrations within the context of the application, simply run `bin/rails +To run these migrations within the context of the application, simply run `rails db:migrate`. When accessing the engine through `http://localhost:3000/blog`, the articles will be empty. This is because the table created inside the application is different from the one created within the engine. Go ahead, play around with the @@ -734,14 +737,14 @@ If you would like to run migrations only from one engine, you can do it by specifying `SCOPE`: ```bash -bin/rails db:migrate SCOPE=blorgh +rails db:migrate SCOPE=blorgh ``` This may be useful if you want to revert engine's migrations before removing it. To revert all migrations from blorgh engine you can run code such as: ```bash -bin/rails db:migrate SCOPE=blorgh VERSION=0 +rails db:migrate SCOPE=blorgh VERSION=0 ``` ### Using a Class Provided by the Application @@ -768,7 +771,7 @@ application: rails g model user name:string ``` -The `bin/rails db:migrate` command needs to be run here to ensure that our +The `rails db:migrate` command needs to be run here to ensure that our application has the `users` table for future use. Also, to keep it simple, the articles form will have a new text field called @@ -828,7 +831,7 @@ of associating the records in the `blorgh_articles` table with the records in th To generate this new column, run this command within the engine: ```bash -$ bin/rails g migration add_author_id_to_blorgh_articles author_id:integer +$ rails g migration add_author_id_to_blorgh_articles author_id:integer ``` NOTE: Due to the migration's name and the column specification after it, Rails @@ -840,7 +843,7 @@ This migration will need to be run on the application. To do that, it must first be copied using this command: ```bash -$ bin/rails blorgh:install:migrations +$ rails blorgh:install:migrations ``` Notice that only _one_ migration was copied over here. This is because the first @@ -855,7 +858,7 @@ Copied migration [timestamp]_add_author_id_to_blorgh_articles.blorgh.rb from blo Run the migration using: ```bash -$ bin/rails db:migrate +$ rails db:migrate ``` Now with all the pieces in place, an action will take place that will associate @@ -998,7 +1001,7 @@ some sort of identifier by which it can be referenced. #### General Engine Configuration Within an engine, there may come a time where you wish to use things such as -initializers, internationalization or other configuration options. The great +initializers, internationalization, or other configuration options. The great news is that these things are entirely possible, because a Rails engine shares much the same functionality as a Rails application. In fact, a Rails application's functionality is actually a superset of what is provided by @@ -1020,11 +1023,11 @@ Testing an engine When an engine is generated, there is a smaller dummy application created inside it at `test/dummy`. This application is used as a mounting point for the engine, to make testing the engine extremely simple. You may extend this application by -generating controllers, models or views from within the directory, and then use +generating controllers, models, or views from within the directory, and then use those to test your engine. The `test` directory should be treated like a typical Rails testing environment, -allowing for unit, functional and integration tests. +allowing for unit, functional, and integration tests. ### Functional Tests @@ -1362,7 +1365,7 @@ need to require `admin.css` or `admin.js`. Only the gem's admin layout needs these assets. It doesn't make sense for the host app to include `"blorgh/admin.css"` in its stylesheets. In this situation, you should explicitly define these assets for precompilation. This tells Sprockets to add -your engine assets when `bin/rails assets:precompile` is triggered. +your engine assets when `rails assets:precompile` is triggered. You can define assets for precompilation in `engine.rb`: |