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Diffstat (limited to 'guides/source/getting_started.md')
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1 files changed, 55 insertions, 44 deletions
diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md index 5700e71103..4431512eda 100644 --- a/guides/source/getting_started.md +++ b/guides/source/getting_started.md @@ -37,6 +37,7 @@ curve diving straight into Rails. There are several curated lists of online reso for learning Ruby: * [Official Ruby Programming Language website](https://www.ruby-lang.org/en/documentation/) +* [List of Free Programming Books](https://github.com/vhf/free-programming-books/blob/master/free-programming-books.md#ruby) Be aware that some resources, while still excellent, cover versions of Ruby as old as 1.6, and commonly 1.8, and will not include some syntax that you will see in day-to-day @@ -92,7 +93,7 @@ current version of Ruby installed: ```bash $ ruby -v -ruby 2.2.2p95 +ruby 2.3.0p0 ``` TIP: A number of tools exist to help you quickly install Ruby and Ruby @@ -173,7 +174,7 @@ of the files and folders that Rails created by default: |log/|Application log files.| |public/|The only folder seen by the world as-is. Contains static files and compiled assets.| |Rakefile|This file locates and loads tasks that can be run from the command line. The task definitions are defined throughout the components of Rails. Rather than changing Rakefile, you should add your own tasks by adding files to the lib/tasks directory of your application.| -|README.rdoc|This is a brief instruction manual for your application. You should edit this file to tell others what your application does, how to set it up, and so on.| +|README.md|This is a brief instruction manual for your application. You should edit this file to tell others what your application does, how to set it up, and so on.| |test/|Unit tests, fixtures, and other test apparatus. These are covered in [Testing Rails Applications](testing.html).| |tmp/|Temporary files (like cache and pid files).| |vendor/|A place for all third-party code. In a typical Rails application this includes vendored gems.| @@ -207,7 +208,7 @@ commented line for new apps and you can uncomment if you need it. default to the `Gemfile` in apps generated under JRuby. You can investigate all the supported runtimes at [ExecJS](https://github.com/rails/execjs#readme). -This will fire up WEBrick, a web server distributed with Ruby by default. To see +This will fire up Puma, a web server distributed with Rails by default. To see your application in action, open a browser window and navigate to <http://localhost:3000>. You should see the Rails default information page: @@ -297,26 +298,30 @@ Open the file `config/routes.rb` in your editor. Rails.application.routes.draw do get 'welcome/index' - # The priority is based upon order of creation: - # first created -> highest priority. - # See how all your routes lay out with "rake routes". - # - # You can have the root of your site routed with "root" - # root 'welcome#index' - # - # ... + # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html + + # Serve websocket cable requests in-process + # mount ActionCable.server => '/cable' +end ``` This is your application's _routing file_ which holds entries in a special [DSL (domain-specific language)](http://en.wikipedia.org/wiki/Domain-specific_language) that tells Rails how to connect incoming requests to -controllers and actions. This file contains many sample routes on commented -lines, and one of them actually shows you how to connect the root of your site -to a specific controller and action. Find the line beginning with `root` and -uncomment it. It should look something like the following: +controllers and actions. +Edit this file by adding the line of code `root 'welcome#index'`. +It should look something like the following: ```ruby -root 'welcome#index' +Rails.application.routes.draw do + get 'welcome/index' + + # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html + + # Serve websocket cable requests in-process + # mount ActionCable.server => '/cable' + root 'welcome#index' +end ``` `root 'welcome#index'` tells Rails to map requests to the root of the @@ -347,7 +352,7 @@ operations are referred to as _CRUD_ operations. Rails provides a `resources` method which can be used to declare a standard REST resource. You need to add the _article resource_ to the -`config/routes.rb` as follows: +`config/routes.rb` so the file will look as follows: ```ruby Rails.application.routes.draw do @@ -358,13 +363,13 @@ Rails.application.routes.draw do end ``` -If you run `bin/rake routes`, you'll see that it has defined routes for all the +If you run `bin/rails routes`, you'll see that it has defined routes for all the standard RESTful actions. The meaning of the prefix column (and other columns) will be seen later, but for now notice that Rails has inferred the singular form `article` and makes meaningful use of the distinction. ```bash -$ bin/rake routes +$ bin/rails routes Prefix Verb URI Pattern Controller#Action articles GET /articles(.:format) articles#index POST /articles(.:format) articles#create @@ -558,10 +563,10 @@ this: In this example, the `articles_path` helper is passed to the `:url` option. To see what Rails will do with this, we look back at the output of -`bin/rake routes`: +`bin/rails routes`: ```bash -$ bin/rake routes +$ bin/rails routes Prefix Verb URI Pattern Controller#Action articles GET /articles(.:format) articles#index POST /articles(.:format) articles#create @@ -624,7 +629,7 @@ end The `render` method here is taking a very simple hash with a key of `:plain` and value of `params[:article].inspect`. The `params` method is the object which represents the parameters (or fields) coming in from the form. The `params` -method returns an `ActiveSupport::HashWithIndifferentAccess` object, which +method returns an `ActionController::Parameters` object, which allows you to access the keys of the hash using either strings or symbols. In this situation, the only parameters that matter are the ones from the form. @@ -634,7 +639,7 @@ If you re-submit the form one more time you'll now no longer get the missing template error. Instead, you'll see something that looks like the following: ```ruby -{"title"=>"First article!", "text"=>"This is my first article."} +<ActionController::Parameters {"title"=>"First Article!", "text"=>"This is my first article."} permitted: false> ``` This action is now displaying the parameters for the article that are coming in @@ -652,7 +657,7 @@ run this command in your terminal: $ bin/rails generate model Article title:string text:text ``` -With that command we told Rails that we want a `Article` model, together +With that command we told Rails that we want an `Article` model, together with a _title_ attribute of type string, and a _text_ attribute of type text. Those attributes are automatically added to the `articles` table in the database and mapped to the `Article` model. @@ -679,7 +684,7 @@ If you look in the `db/migrate/YYYYMMDDHHMMSS_create_articles.rb` file (remember, yours will have a slightly different name), here's what you'll find: ```ruby -class CreateArticles < ActiveRecord::Migration +class CreateArticles < ActiveRecord::Migration[5.0] def change create_table :articles do |t| t.string :title @@ -701,10 +706,10 @@ two timestamp fields to allow Rails to track article creation and update times. TIP: For more information about migrations, refer to [Rails Database Migrations] (migrations.html). -At this point, you can use a rake command to run the migration: +At this point, you can use a bin/rails command to run the migration: ```bash -$ bin/rake db:migrate +$ bin/rails db:migrate ``` Rails will execute this migration command and tell you it created the Articles @@ -721,7 +726,7 @@ NOTE. Because you're working in the development environment by default, this command will apply to the database defined in the `development` section of your `config/database.yml` file. If you would like to execute migrations in another environment, for instance in production, you must explicitly pass it when -invoking the command: `bin/rake db:migrate RAILS_ENV=production`. +invoking the command: `bin/rails db:migrate RAILS_ENV=production`. ### Saving data in the controller @@ -766,7 +771,7 @@ Why do you have to bother? The ability to grab and automatically assign all controller parameters to your model in one shot makes the programmer's job easier, but this convenience also allows malicious use. What if a request to the server was crafted to look like a new article form submit but also included -extra fields with values that violated your applications integrity? They would +extra fields with values that violated your application's integrity? They would be 'mass assigned' into your model and then into the database along with the good stuff - potentially breaking your application or worse. @@ -808,7 +813,7 @@ If you submit the form again now, Rails will complain about not finding the `show` action. That's not very useful though, so let's add the `show` action before proceeding. -As we have seen in the output of `bin/rake routes`, the route for `show` action is +As we have seen in the output of `bin/rails routes`, the route for `show` action is as follows: ``` @@ -870,7 +875,7 @@ Visit <http://localhost:3000/articles/new> and give it a try! ### Listing all articles We still need a way to list all our articles, so let's do that. -The route for this as per output of `bin/rake routes` is: +The route for this as per output of `bin/rails routes` is: ``` articles GET /articles(.:format) articles#index @@ -990,21 +995,22 @@ and restart the web server when a change is made. The model file, `app/models/article.rb` is about as simple as it can get: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord end ``` There isn't much to this file - but note that the `Article` class inherits from -`ActiveRecord::Base`. Active Record supplies a great deal of functionality to -your Rails models for free, including basic database CRUD (Create, Read, Update, -Destroy) operations, data validation, as well as sophisticated search support -and the ability to relate multiple models to one another. +`ApplicationRecord`. `ApplicationRecord` inherits from `ActiveRecord::Base` +which supplies a great deal of functionality to your Rails models for free, +including basic database CRUD (Create, Read, Update, Destroy) operations, data +validation, as well as sophisticated search support and the ability to relate +multiple models to one another. Rails includes methods to help you validate the data that you send to models. Open the `app/models/article.rb` file and edit it: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord validates :title, presence: true, length: { minimum: 5 } end @@ -1364,7 +1370,7 @@ Then do the same for the `app/views/articles/edit.html.erb` view: We're now ready to cover the "D" part of CRUD, deleting articles from the database. Following the REST convention, the route for -deleting articles as per output of `bin/rake routes` is: +deleting articles as per output of `bin/rails routes` is: ```ruby DELETE /articles/:id(.:format) articles#destroy @@ -1529,7 +1535,7 @@ This command will generate four files: First, take a look at `app/models/comment.rb`: ```ruby -class Comment < ActiveRecord::Base +class Comment < ApplicationRecord belongs_to :article end ``` @@ -1538,11 +1544,16 @@ This is very similar to the `Article` model that you saw earlier. The difference is the line `belongs_to :article`, which sets up an Active Record _association_. You'll learn a little about associations in the next section of this guide. +The (`:references`) keyword used in the bash command is a special data type for models. +It creates a new column on your database table with the provided model name appended with an `_id` +that can hold integer values. You can get a better understanding after analyzing the +`db/schema.rb` file below. + In addition to the model, Rails has also made a migration to create the corresponding database table: ```ruby -class CreateComments < ActiveRecord::Migration +class CreateComments < ActiveRecord::Migration[5.0] def change create_table :comments do |t| t.string :commenter @@ -1560,7 +1571,7 @@ for it, and a foreign key constraint that points to the `id` column of the `arti table. Go ahead and run the migration: ```bash -$ bin/rake db:migrate +$ bin/rails db:migrate ``` Rails is smart enough to only execute the migrations that have not already been @@ -1587,7 +1598,7 @@ association. You've already seen the line of code inside the `Comment` model (app/models/comment.rb) that makes each comment belong to an Article: ```ruby -class Comment < ActiveRecord::Base +class Comment < ApplicationRecord belongs_to :article end ``` @@ -1596,7 +1607,7 @@ You'll need to edit `app/models/article.rb` to add the other side of the association: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments validates :title, presence: true, length: { minimum: 5 } @@ -1962,7 +1973,7 @@ you to use the `dependent` option of an association to achieve this. Modify the Article model, `app/models/article.rb`, as follows: ```ruby -class Article < ActiveRecord::Base +class Article < ApplicationRecord has_many :comments, dependent: :destroy validates :title, presence: true, length: { minimum: 5 } |