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diff --git a/guides/source/engines.md b/guides/source/engines.md index 8f9ba0995f..e7f024f1fc 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -36,14 +36,14 @@ engine **can** be a plugin, and a plugin **can** be an engine. The engine that will be created in this guide will be called "blorgh". The engine will provide blogging functionality to its host applications, allowing -for new posts and comments to be created. At the beginning of this guide, you +for new articles and comments to be created. At the beginning of this guide, you will be working solely within the engine itself, but in later sections you'll see how to hook it into an application. Engines can also be isolated from their host applications. This means that an application is able to have a path provided by a routing helper such as -`posts_path` and use an engine also that provides a path also called -`posts_path`, and the two would not clash. Along with this, controllers, models +`articles_path` and use an engine also that provides a path also called +`articles_path`, and the two would not clash. Along with this, controllers, models and table names are also namespaced. You'll see how to do this later in this guide. @@ -73,13 +73,13 @@ options as appropriate to the need. For the "blorgh" example, you will need to create a "mountable" engine, running this command in a terminal: ```bash -$ rails plugin new blorgh --mountable +$ bin/rails plugin new blorgh --mountable ``` The full list of options for the plugin generator may be seen by typing: ```bash -$ rails plugin --help +$ bin/rails plugin --help ``` The `--full` option tells the generator that you want to create an engine, @@ -197,12 +197,12 @@ 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 `rails g model`, such as `rails g model post`, won't be called `Post`, but -instead be namespaced and called `Blorgh::Post`. In addition, the table for the -model is namespaced, becoming `blorgh_posts`, rather than simply `posts`. -Similar to the model namespacing, a controller called `PostsController` becomes -`Blorgh::PostsController` and the views for that controller will not be at -`app/views/posts`, but `app/views/blorgh/posts` instead. Mailers are namespaced +to `bin/rails g model`, such as `bin/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 +`Blorgh::ArticlesController` and the views for that controller will not be at +`app/views/articles`, but `app/views/blorgh/articles` instead. Mailers are namespaced as well. Finally, routes will also be isolated within the engine. This is one of the most @@ -253,7 +253,7 @@ This means that you will be able to generate new controllers and models for this engine very easily by running commands like this: ```bash -rails g model +$ bin/rails g model ``` Keep in mind, of course, that anything generated with these commands inside of @@ -283,74 +283,74 @@ created in the `test` directory as well. For example, you may wish to create a Providing engine functionality ------------------------------ -The engine that this guide covers provides posting and commenting functionality -and follows a similar thread to the [Getting Started +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. -### Generating a Post Resource +### Generating an Article Resource -The first thing to generate for a blog engine is the `Post` model and related +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 -$ rails generate scaffold post title:string text:text +$ bin/rails generate scaffold article title:string text:text ``` This command will output this information: ``` invoke active_record -create db/migrate/[timestamp]_create_blorgh_posts.rb -create app/models/blorgh/post.rb +create db/migrate/[timestamp]_create_blorgh_articles.rb +create app/models/blorgh/article.rb invoke test_unit -create test/models/blorgh/post_test.rb -create test/fixtures/blorgh/posts.yml +create test/models/blorgh/article_test.rb +create test/fixtures/blorgh/articles.yml invoke resource_route - route resources :posts + route resources :articles invoke scaffold_controller -create app/controllers/blorgh/posts_controller.rb +create app/controllers/blorgh/articles_controller.rb invoke erb -create app/views/blorgh/posts -create app/views/blorgh/posts/index.html.erb -create app/views/blorgh/posts/edit.html.erb -create app/views/blorgh/posts/show.html.erb -create app/views/blorgh/posts/new.html.erb -create app/views/blorgh/posts/_form.html.erb +create app/views/blorgh/articles +create app/views/blorgh/articles/index.html.erb +create app/views/blorgh/articles/edit.html.erb +create app/views/blorgh/articles/show.html.erb +create app/views/blorgh/articles/new.html.erb +create app/views/blorgh/articles/_form.html.erb invoke test_unit -create test/controllers/blorgh/posts_controller_test.rb +create test/controllers/blorgh/articles_controller_test.rb invoke helper -create app/helpers/blorgh/posts_helper.rb +create app/helpers/blorgh/articles_helper.rb invoke test_unit -create test/helpers/blorgh/posts_helper_test.rb +create test/helpers/blorgh/articles_helper_test.rb invoke assets invoke js -create app/assets/javascripts/blorgh/posts.js +create app/assets/javascripts/blorgh/articles.js invoke css -create app/assets/stylesheets/blorgh/posts.css +create app/assets/stylesheets/blorgh/articles.css invoke css create app/assets/stylesheets/scaffold.css ``` The first thing that the scaffold generator does is invoke the `active_record` generator, which generates a migration and a model for the resource. Note here, -however, that the migration is called `create_blorgh_posts` rather than the -usual `create_posts`. This is due to the `isolate_namespace` method called in +however, that the migration is called `create_blorgh_articles` rather than the +usual `create_articles`. This is due to the `isolate_namespace` method called in the `Blorgh::Engine` class's definition. The model here is also namespaced, -being placed at `app/models/blorgh/post.rb` rather than `app/models/post.rb` due +being placed at `app/models/blorgh/article.rb` rather than `app/models/article.rb` due to the `isolate_namespace` call within the `Engine` class. Next, the `test_unit` generator is invoked for this model, generating a model -test at `test/models/blorgh/post_test.rb` (rather than -`test/models/post_test.rb`) and a fixture at `test/fixtures/blorgh/posts.yml` -(rather than `test/fixtures/posts.yml`). +test at `test/models/blorgh/article_test.rb` (rather than +`test/models/article_test.rb`) and a fixture at `test/fixtures/blorgh/articles.yml` +(rather than `test/fixtures/articles.yml`). After that, a line for the resource is inserted into the `config/routes.rb` file -for the engine. This line is simply `resources :posts`, turning the +for the engine. This line is simply `resources :articles`, turning the `config/routes.rb` file for the engine into this: ```ruby Blorgh::Engine.routes.draw do - resources :posts + resources :articles end ``` @@ -362,18 +362,18 @@ be isolated from those routes that are within the application. The [Routes](#routes) section of this guide describes it in detail. Next, the `scaffold_controller` generator is invoked, generating a controller -called `Blorgh::PostsController` (at -`app/controllers/blorgh/posts_controller.rb`) and its related views at -`app/views/blorgh/posts`. This generator also generates a test for the -controller (`test/controllers/blorgh/posts_controller_test.rb`) and a helper -(`app/helpers/blorgh/posts_controller.rb`). +called `Blorgh::ArticlesController` (at +`app/controllers/blorgh/articles_controller.rb`) and its related views at +`app/views/blorgh/articles`. This generator also generates a test for the +controller (`test/controllers/blorgh/articles_controller_test.rb`) and a helper +(`app/helpers/blorgh/articles_controller.rb`). Everything this generator has created is neatly namespaced. The controller's class is defined within the `Blorgh` module: ```ruby module Blorgh - class PostsController < ApplicationController + class ArticlesController < ApplicationController ... end end @@ -382,22 +382,22 @@ end NOTE: The `ApplicationController` class being inherited from here is the `Blorgh::ApplicationController`, not an application's `ApplicationController`. -The helper inside `app/helpers/blorgh/posts_helper.rb` is also namespaced: +The helper inside `app/helpers/blorgh/articles_helper.rb` is also namespaced: ```ruby module Blorgh - module PostsHelper + module ArticlesHelper ... end end ``` This helps prevent conflicts with any other engine or application that may have -a post resource as well. +a article resource as well. Finally, the assets for this resource are generated in two files: -`app/assets/javascripts/blorgh/posts.js` and -`app/assets/stylesheets/blorgh/posts.css`. You'll see how to use these a little +`app/assets/javascripts/blorgh/articles.js` and +`app/assets/stylesheets/blorgh/articles.css`. You'll see how to use these a little later. By default, the scaffold styling is not applied to the engine because the @@ -412,46 +412,46 @@ tag of this layout: You can see what the engine has so far by running `rake 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/posts` you will see the default scaffold that has +`http://localhost:3000/blorgh/articles` you will see the default scaffold that has been generated. Click around! You've just generated your first engine's first functions. If you'd rather play around in the console, `rails console` will also work just -like a Rails application. Remember: the `Post` model is namespaced, so to -reference it you must call it as `Blorgh::Post`. +like a Rails application. Remember: the `Article` model is namespaced, so to +reference it you must call it as `Blorgh::Article`. ```ruby ->> Blorgh::Post.find(1) -=> #<Blorgh::Post id: 1 ...> +>> Blorgh::Article.find(1) +=> #<Blorgh::Article id: 1 ...> ``` -One final thing is that the `posts` resource for this engine should be the root +One final thing is that the `articles` resource for this engine should be the root of the engine. Whenever someone goes to the root path where the engine is -mounted, they should be shown a list of posts. This can be made to happen if +mounted, they should be shown a list of articles. This can be made to happen if this line is inserted into the `config/routes.rb` file inside the engine: ```ruby -root to: "posts#index" +root to: "articles#index" ``` -Now people will only need to go to the root of the engine to see all the posts, -rather than visiting `/posts`. This means that instead of -`http://localhost:3000/blorgh/posts`, you only need to go to +Now people will only need to go to the root of the engine to see all the articles, +rather than visiting `/articles`. This means that instead of +`http://localhost:3000/blorgh/articles`, you only need to go to `http://localhost:3000/blorgh` now. ### Generating a Comments Resource -Now that the engine can create new blog posts, it only makes sense to add +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 posts 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 -`Comment` model, with the related table having two columns: a `post_id` integer +`Comment` model, with the related table having two columns: a `article_id` integer and `text` text column. ```bash -$ rails generate model Comment post_id:integer text:text +$ bin/rails generate model Comment article_id:integer text:text ``` This will output the following: @@ -474,17 +474,17 @@ table: $ rake db:migrate ``` -To show the comments on a post, edit `app/views/blorgh/posts/show.html.erb` and +To show the comments on an article, edit `app/views/blorgh/articles/show.html.erb` and add this line before the "Edit" link: ```html+erb <h3>Comments</h3> -<%= render @post.comments %> +<%= render @article.comments %> ``` This line will require there to be a `has_many` association for comments defined -on the `Blorgh::Post` model, which there isn't right now. To define one, open -`app/models/blorgh/post.rb` and add this line into the model: +on the `Blorgh::Article` model, which there isn't right now. To define one, open +`app/models/blorgh/article.rb` and add this line into the model: ```ruby has_many :comments @@ -494,7 +494,7 @@ Turning the model into this: ```ruby module Blorgh - class Post < ActiveRecord::Base + class Article < ActiveRecord::Base has_many :comments end end @@ -505,9 +505,9 @@ NOTE: Because the `has_many` is defined inside a class that is inside the model for these objects, so there's no need to specify that using the `:class_name` option here. -Next, there needs to be a form so that comments can be created on a post. To add -this, put this line underneath the call to `render @post.comments` in -`app/views/blorgh/posts/show.html.erb`: +Next, there needs to be a form so that comments can be created on a article. To add +this, put this line underneath the call to `render @article.comments` in +`app/views/blorgh/articles/show.html.erb`: ```erb <%= render "blorgh/comments/form" %> @@ -519,7 +519,7 @@ directory at `app/views/blorgh/comments` and in it a new file called ```html+erb <h3>New comment</h3> -<%= form_for [@post, @post.comments.build] do |f| %> +<%= form_for [@article, @article.comments.build] do |f| %> <p> <%= f.label :text %><br> <%= f.text_area :text %> @@ -529,12 +529,12 @@ directory at `app/views/blorgh/comments` and in it a new file called ``` When this form is submitted, it is going to attempt to perform a `POST` request -to a route of `/posts/:post_id/comments` within the engine. This route doesn't -exist at the moment, but can be created by changing the `resources :posts` line +to a route of `/articles/:article_id/comments` within the engine. This route doesn't +exist at the moment, but can be created by changing the `resources :articles` line inside `config/routes.rb` into these lines: ```ruby -resources :posts do +resources :articles do resources :comments end ``` @@ -545,7 +545,7 @@ 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 -$ rails g controller comments +$ bin/rails g controller comments ``` This will generate the following things: @@ -567,17 +567,17 @@ invoke css create app/assets/stylesheets/blorgh/comments.css ``` -The form will be making a `POST` request to `/posts/:post_id/comments`, which +The form will be making a `POST` request to `/articles/:article_id/comments`, which will correspond with the `create` action in `Blorgh::CommentsController`. This action needs to be created, which can be done by putting the following lines inside the class definition in `app/controllers/blorgh/comments_controller.rb`: ```ruby def create - @post = Post.find(params[:post_id]) - @comment = @post.comments.create(comment_params) + @article = Article.find(params[:article_id]) + @comment = @article.comments.create(comment_params) flash[:notice] = "Comment has been created!" - redirect_to posts_path + redirect_to articles_path end private @@ -590,11 +590,11 @@ This is the final step required to get the new comment form working. Displaying the comments, however, is not quite right yet. If you were to create a comment right now, you would see this error: -``` +``` Missing partial blorgh/comments/comment with {:handlers=>[:erb, :builder], :formats=>[:html], :locale=>[:en, :en]}. Searched in: * "/Users/ryan/Sites/side_projects/blorgh/test/dummy/app/views" * -"/Users/ryan/Sites/side_projects/blorgh/app/views" +"/Users/ryan/Sites/side_projects/blorgh/app/views" ``` The engine is unable to find the partial required for rendering the comments. @@ -612,7 +612,7 @@ line inside it: ``` The `comment_counter` local variable is given to us by the `<%= render -@post.comments %>` call, which will define it automatically and increment the +@article.comments %>` call, which will define it automatically and increment the counter as it iterates through each comment. It's used in this example to display a small number next to each comment when it's created. @@ -625,7 +625,7 @@ Hooking Into an Application Using an engine within an application is very easy. This section covers how to mount the engine into an application and the initial setup required, as well as linking the engine to a `User` class provided by the application to provide -ownership for posts and comments within the engine. +ownership for articles and comments within the engine. ### Mounting the Engine @@ -676,7 +676,7 @@ pre-defined path which may be customizable. ### Engine setup -The engine contains migrations for the `blorgh_posts` and `blorgh_comments` +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 use this command: @@ -698,7 +698,7 @@ haven't been copied over already. The first run for this command will output something such as this: ```bash -Copied migration [timestamp_1]_create_blorgh_posts.rb from blorgh +Copied migration [timestamp_1]_create_blorgh_articles.rb from blorgh Copied migration [timestamp_2]_create_blorgh_comments.rb from blorgh ``` @@ -709,7 +709,7 @@ migrations in the application. To run these migrations within the context of the application, simply run `rake db:migrate`. When accessing the engine through `http://localhost:3000/blog`, the -posts will be empty. This is because the table created inside the application is +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 newly mounted engine. You'll find that it's the same as when it was only an engine. @@ -734,11 +734,11 @@ rake db:migrate SCOPE=blorgh VERSION=0 When an engine is created, it may want to use specific classes from an application to provide links between the pieces of the engine and the pieces of -the application. In the case of the `blorgh` engine, making posts and comments +the application. In the case of the `blorgh` engine, making articles and comments have authors would make a lot of sense. A typical application might have a `User` class that would be used to represent -authors for a post or a comment. But there could be a case where the application +authors for a article or a comment. But there could be a case where the application calls this class something different, such as `Person`. For this reason, the engine should not hardcode associations specifically for a `User` class. @@ -753,14 +753,14 @@ rails g model user name:string The `rake 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 posts form will have a new text field called +Also, to keep it simple, the articles form will have a new text field called `author_name`, where users can elect to put their name. The engine will then take this name and either create a new `User` object from it, or find one that -already has that name. The engine will then associate the post with the found or +already has that name. The engine will then associate the article with the found or created `User` object. First, the `author_name` text field needs to be added to the -`app/views/blorgh/posts/_form.html.erb` partial inside the engine. This can be +`app/views/blorgh/articles/_form.html.erb` partial inside the engine. This can be added above the `title` field with this code: ```html+erb @@ -770,23 +770,23 @@ added above the `title` field with this code: </div> ``` -Next, we need to update our `Blorgh::PostController#post_params` method to +Next, we need to update our `Blorgh::ArticleController#article_params` method to permit the new form parameter: ```ruby -def post_params - params.require(:post).permit(:title, :text, :author_name) +def article_params + params.require(:article).permit(:title, :text, :author_name) end ``` -The `Blorgh::Post` model should then have some code to convert the `author_name` -field into an actual `User` object and associate it as that post's `author` -before the post is saved. It will also need to have an `attr_accessor` set up +The `Blorgh::Article` model should then have some code to convert the `author_name` +field into an actual `User` object and associate it as that article's `author` +before the article is saved. It will also need to have an `attr_accessor` set up for this field, so that the setter and getter methods are defined for it. To do all this, you'll need to add the `attr_accessor` for `author_name`, the association for the author and the `before_save` call into -`app/models/blorgh/post.rb`. The `author` association will be hard-coded to the +`app/models/blorgh/article.rb`. The `author` association will be hard-coded to the `User` class for the time being. ```ruby @@ -803,14 +803,14 @@ private By representing the `author` association's object with the `User` class, a link is established between the engine and the application. There needs to be a way -of associating the records in the `blorgh_posts` table with the records in the +of associating the records in the `blorgh_articles` table with the records in the `users` table. Because the association is called `author`, there should be an -`author_id` column added to the `blorgh_posts` table. +`author_id` column added to the `blorgh_articles` table. To generate this new column, run this command within the engine: ```bash -$ rails g migration add_author_id_to_blorgh_posts author_id:integer +$ bin/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 @@ -828,12 +828,12 @@ $ rake blorgh:install:migrations Notice that only _one_ migration was copied over here. This is because the first two migrations were copied over the first time this command was run. -``` -NOTE Migration [timestamp]_create_blorgh_posts.rb from blorgh has been +``` +NOTE Migration [timestamp]_create_blorgh_articles.rb from blorgh has been skipped. Migration with the same name already exists. NOTE Migration [timestamp]_create_blorgh_comments.rb from blorgh has been skipped. Migration with the same name already exists. Copied migration -[timestamp]_add_author_id_to_blorgh_posts.rb from blorgh +[timestamp]_add_author_id_to_blorgh_articles.rb from blorgh ``` Run the migration using: @@ -843,20 +843,20 @@ $ rake db:migrate ``` Now with all the pieces in place, an action will take place that will associate -an author - represented by a record in the `users` table - with a post, -represented by the `blorgh_posts` table from the engine. +an author - represented by a record in the `users` table - with an article, +represented by the `blorgh_articles` table from the engine. -Finally, the author's name should be displayed on the post's page. Add this code -above the "Title" output inside `app/views/blorgh/posts/show.html.erb`: +Finally, the author's name should be displayed on the article's page. Add this code +above the "Title" output inside `app/views/blorgh/articles/show.html.erb`: ```html+erb <p> <b>Author:</b> - <%= @post.author %> + <%= @article.author %> </p> ``` -By outputting `@post.author` using the `<%=` tag, the `to_s` method will be +By outputting `@article.author` using the `<%=` tag, the `to_s` method will be called on the object. By default, this will look quite ugly: ``` @@ -925,15 +925,15 @@ This method works like its brothers, `attr_accessor` and `cattr_accessor`, but provides a setter and getter method on the module with the specified name. To use it, it must be referenced using `Blorgh.author_class`. -The next step is to switch the `Blorgh::Post` model over to this new setting. +The next step is to switch the `Blorgh::Article` model over to this new setting. Change the `belongs_to` association inside this model -(`app/models/blorgh/post.rb`) to this: +(`app/models/blorgh/article.rb`) to this: ```ruby belongs_to :author, class_name: Blorgh.author_class ``` -The `set_author` method in the `Blorgh::Post` model should also use this class: +The `set_author` method in the `Blorgh::Article` model should also use this class: ```ruby self.author = Blorgh.author_class.constantize.find_or_create_by(name: author_name) @@ -960,7 +960,7 @@ Resulting in something a little shorter, and more implicit in its behavior. The `author_class` method should always return a `Class` object. Since we changed the `author_class` method to return a `Class` instead of a -`String`, we must also modify our `belongs_to` definition in the `Blorgh::Post` +`String`, we must also modify our `belongs_to` definition in the `Blorgh::Article` model: ```ruby @@ -985,14 +985,14 @@ to load that class and then reference the related table. This could lead to problems if the table wasn't already existing. Therefore, a `String` should be used and then converted to a class using `constantize` in the engine later on. -Go ahead and try to create a new post. You will see that it works exactly in the +Go ahead and try to create a new article. You will see that it works exactly in the same way as before, except this time the engine is using the configuration setting in `config/initializers/blorgh.rb` to learn what the class is. There are now no strict dependencies on what the class is, only what the API for the class must be. The engine simply requires this class to define a `find_or_create_by` method which returns an object of that class, to be -associated with a post when it's created. This object, of course, should have +associated with an article when it's created. This object, of course, should have some sort of identifier by which it can be referenced. #### General Engine Configuration @@ -1107,12 +1107,12 @@ that isn't referenced by your main application. #### Implementing Decorator Pattern Using Class#class_eval -**Adding** `Post#time_since_created`: +**Adding** `Article#time_since_created`: ```ruby -# MyApp/app/decorators/models/blorgh/post_decorator.rb +# MyApp/app/decorators/models/blorgh/article_decorator.rb -Blorgh::Post.class_eval do +Blorgh::Article.class_eval do def time_since_created Time.current - created_at end @@ -1120,20 +1120,20 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments end ``` -**Overriding** `Post#summary`: +**Overriding** `Article#summary`: ```ruby -# MyApp/app/decorators/models/blorgh/post_decorator.rb +# MyApp/app/decorators/models/blorgh/article_decorator.rb -Blorgh::Post.class_eval do +Blorgh::Article.class_eval do def summary "#{title} - #{truncate(text)}" end @@ -1141,9 +1141,9 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base +class Article < ActiveRecord::Base has_many :comments def summary "#{title}" @@ -1159,13 +1159,13 @@ class modifications, you might want to consider using [`ActiveSupport::Concern`] ActiveSupport::Concern manages load order of interlinked dependent modules and classes at run time allowing you to significantly modularize your code. -**Adding** `Post#time_since_created` and **Overriding** `Post#summary`: +**Adding** `Article#time_since_created` and **Overriding** `Article#summary`: ```ruby -# MyApp/app/models/blorgh/post.rb +# MyApp/app/models/blorgh/article.rb -class Blorgh::Post < ActiveRecord::Base - include Blorgh::Concerns::Models::Post +class Blorgh::Article < ActiveRecord::Base + include Blorgh::Concerns::Models::Article def time_since_created Time.current - created_at @@ -1178,22 +1178,22 @@ end ``` ```ruby -# Blorgh/app/models/post.rb +# Blorgh/app/models/article.rb -class Post < ActiveRecord::Base - include Blorgh::Concerns::Models::Post +class Article < ActiveRecord::Base + include Blorgh::Concerns::Models::Article end ``` ```ruby -# Blorgh/lib/concerns/models/post +# Blorgh/lib/concerns/models/article -module Blorgh::Concerns::Models::Post +module Blorgh::Concerns::Models::Article extend ActiveSupport::Concern # 'included do' causes the included code to be evaluated in the - # context where it is included (post.rb), rather than being - # executed in the module's context (blorgh/concerns/models/post). + # context where it is included (article.rb), rather than being + # executed in the module's context (blorgh/concerns/models/article). included do attr_accessor :author_name belongs_to :author, class_name: "User" @@ -1224,25 +1224,25 @@ When Rails looks for a view to render, it will first look in the `app/views` directory of the application. If it cannot find the view there, it will check in the `app/views` directories of all engines that have this directory. -When the application is asked to render the view for `Blorgh::PostsController`'s +When the application is asked to render the view for `Blorgh::ArticlesController`'s index action, it will first look for the path -`app/views/blorgh/posts/index.html.erb` within the application. If it cannot +`app/views/blorgh/articles/index.html.erb` within the application. If it cannot find it, it will look inside the engine. You can override this view in the application by simply creating a new file at -`app/views/blorgh/posts/index.html.erb`. Then you can completely change what +`app/views/blorgh/articles/index.html.erb`. Then you can completely change what this view would normally output. -Try this now by creating a new file at `app/views/blorgh/posts/index.html.erb` +Try this now by creating a new file at `app/views/blorgh/articles/index.html.erb` and put this content in it: ```html+erb -<h1>Posts</h1> -<%= link_to "New Post", new_post_path %> -<% @posts.each do |post| %> - <h2><%= post.title %></h2> - <small>By <%= post.author %></small> - <%= simple_format(post.text) %> +<h1>Articles</h1> +<%= link_to "New Article", new_article_path %> +<% @articles.each do |article| %> + <h2><%= article.title %></h2> + <small>By <%= article.author %></small> + <%= simple_format(article.text) %> <hr> <% end %> ``` @@ -1259,30 +1259,30 @@ Routes inside an engine are drawn on the `Engine` class within ```ruby Blorgh::Engine.routes.draw do - resources :posts + resources :articles end ``` By having isolated routes such as this, if you wish to link to an area of an engine from within an application, you will need to use the engine's routing -proxy method. Calls to normal routing methods such as `posts_path` may end up +proxy method. Calls to normal routing methods such as `articles_path` may end up going to undesired locations if both the application and the engine have such a helper defined. -For instance, the following example would go to the application's `posts_path` -if that template was rendered from the application, or the engine's `posts_path` +For instance, the following example would go to the application's `articles_path` +if that template was rendered from the application, or the engine's `articles_path` if it was rendered from the engine: ```erb -<%= link_to "Blog posts", posts_path %> +<%= link_to "Blog articles", articles_path %> ``` -To make this route always use the engine's `posts_path` routing helper method, +To make this route always use the engine's `articles_path` routing helper method, we must call the method on the routing proxy method that shares the same name as the engine. ```erb -<%= link_to "Blog posts", blorgh.posts_path %> +<%= link_to "Blog articles", blorgh.articles_path %> ``` If you wish to reference the application inside the engine in a similar way, use |