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Diffstat (limited to 'guides/source/engines.md')
| -rw-r--r-- | guides/source/engines.md | 40 |
1 files changed, 28 insertions, 12 deletions
diff --git a/guides/source/engines.md b/guides/source/engines.md index bc66ed256e..c71b728ef7 100644 --- a/guides/source/engines.md +++ b/guides/source/engines.md @@ -104,7 +104,7 @@ At the root of this brand new engine's directory lives a `blorgh.gemspec` file. gem 'blorgh', path: "vendor/engines/blorgh" ``` -By specifying it as a gem within the `Gemfile`, Bundler will load it as such, parsing this `blorgh.gemspec` file and requiring a file within the `lib` directory called `lib/blorgh.rb`. This file requires the `blorgh/engine.rb` file (located at `lib/blorgh/engine.rb`) and defines a base module called `Blorgh`. +Don't forget to run `bundle install` as usual. By specifying it as a gem within the `Gemfile`, Bundler will load it as such, parsing this `blorgh.gemspec` file and requiring a file within the `lib` directory called `lib/blorgh.rb`. This file requires the `blorgh/engine.rb` file (located at `lib/blorgh/engine.rb`) and defines a base module called `Blorgh`. ```ruby require "blorgh/engine" @@ -307,7 +307,11 @@ create test/models/blorgh/comment_test.rb create test/fixtures/blorgh/comments.yml ``` -This generator call will generate just the necessary model files it needs, namespacing the files under a `blorgh` directory and creating a model class called `Blorgh::Comment`. +This generator call will generate just the necessary model files it needs, namespacing the files under a `blorgh` directory and creating a model class called `Blorgh::Comment`. Now run the migration to create our blorgh_comments table: + +```bash +$ rake db:migrate +``` To show the comments on a post, edit `app/views/blorgh/posts/show.html.erb` and add this line before the "Edit" link: @@ -346,7 +350,7 @@ Next, the partial that this line will render needs to exist. Create a new direct <h3>New comment</h3> <%= form_for [@post, @post.comments.build] do |f| %> <p> - <%= f.label :text %><br /> + <%= f.label :text %><br> <%= f.text_area :text %> </p> <%= f.submit %> @@ -393,10 +397,15 @@ The form will be making a `POST` request to `/posts/:post_id/comments`, which wi ```ruby def create @post = Post.find(params[:post_id]) - @comment = @post.comments.create(params[:comment]) + @comment = @post.comments.create(comment_params) flash[:notice] = "Comment has been created!" redirect_to posts_path end + +private + def comment_params + params.require(:comment).permit(:text) + end ``` This is the final part 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: @@ -461,7 +470,7 @@ NOTE: Other engines, such as Devise, handle this a little differently by making The engine contains migrations for the `blorgh_posts` 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: ```bash -$ rake blorgh_engine:install:migrations +$ rake blorgh:install:migrations ``` If you have multiple engines that need migrations copied over, use `railties:install:migrations` instead: @@ -515,11 +524,19 @@ First, the `author_name` text field needs to be added to the `app/views/blorgh/p ```html+erb <div class="field"> - <%= f.label :author_name %><br /> + <%= f.label :author_name %><br> <%= f.text_field :author_name %> </div> ``` +Next, we need to update our `Blorgh::PostController#post_params` method to permit the new form parameter: + +```ruby +def post_params + params.require(:post).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` setup 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 `User` class for the time being. @@ -566,7 +583,7 @@ Run this migration using this command: $ 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. +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. 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`: @@ -676,8 +693,8 @@ There are now no strict dependencies on what the class is, only what the API for Within an engine, there may come a time where you wish to use things such as 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 engines! -If you wish to use an initializer — code that should run before the engine is -loaded — the place for it is the `config/initializers` folder. This directory's +If you wish to use an initializer - code that should run before the engine is +loaded - the place for it is the `config/initializers` folder. This directory's functionality is explained in the [Initializers section](configuring.html#initializers) of the Configuring guide, and works precisely the same way as the `config/initializers` directory inside @@ -694,7 +711,7 @@ The `test` directory should be treated like a typical Rails testing environment, ### Functional tests -A matter worth taking into consideration when writing functional tests is that the tests are going to be running on an application — the `test/dummy` application — rather than your engine. This is due to the setup of the testing environment; an engine needs an application as a host for testing its main functionality, especially controllers. This means that if you were to make a typical `GET` to a controller in a controller's functional test like this: +A matter worth taking into consideration when writing functional tests is that the tests are going to be running on an application - the `test/dummy` application - rather than your engine. This is due to the setup of the testing environment; an engine needs an application as a host for testing its main functionality, especially controllers. This means that if you were to make a typical `GET` to a controller in a controller's functional test like this: ```ruby get :index @@ -837,7 +854,6 @@ module Blorgh::Concerns::Models::Post before_save :set_author private - def set_author self.author = User.find_or_create_by(name: author_name) end @@ -938,7 +954,7 @@ INFO. Remember that in order to use languages like Sass or CoffeeScript, you sho There are some situations where your engine's assets are not required by the host application. For example, say that you've created an admin functionality that only exists for your engine. In this case, the host application doesn't 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 `"blorg/admin.css"` in it's stylesheets. In this situation, you should explicitly define these assets for precompilation. +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 it's stylesheets. In this situation, you should explicitly define these assets for precompilation. This tells sprockets to add your engine assets when `rake assets:precompile` is ran. You can define assets for precompilation in `engine.rb` |