Ruby on Rails 4
Features and demonstration of Rails 4.
Notes
Key Features of Rails 4
- Ruby 2.0 preferred; 1.9.3+ required
- Strong Parameters
- Turbolinks
- Russian Doll Caching
Checking Pre-requisites and Installation
$ ruby -v
ruby 2.4.3p205 (2017-12-14 revision 61247) [x86_64-darwin17]
$ sqlite3 --version
3.19.3 2017-06-27 16:48:08 2b0954060fe10d6de6d479287dd88890f1bef6cc1beca11bc6cdb79f72e2377b
$ gem install rails -v 4.2.11
...
$ rails --version
Rails 4.2.11
Note
- Tests cause ThreadError: already initialized with Ruby 2.6.0
warning: BigDecimal.new is deprecated; use BigDecimal() method instead.- with 2.6.0
Creating a Simple App
$ rails new minime4
...
$ cd minime4
$ rake db:migrate
$ rails server
=> Booting WEBrick
=> Rails 4.2.11 application starting in development on http://localhost:3000
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
[2019-02-26 11:35:32] INFO WEBrick 1.3.1
[2019-02-26 11:35:32] INFO ruby 2.4.3 (2017-12-14) [x86_64-darwin17]
[2019-02-26 11:35:32] INFO WEBrick::HTTPServer#start: pid=65375 port=3000
Gem::LoadError: can’t activate sqlite3 (~> 1.3.6), already activated sqlite3-1.4.0. Make sure all dependencies are added to Gemfile.
Update Gemfile to pin gem 'sqlite3', '~> 1.3.6' and re-run bundle
Hit http://localhost:3000..
Adding a Welcome Page
Using controller generator:
rails generate controller Welcome index
Adjust routes to use this as the main page.
Testing
$ rake test
Running via Spring preloader in process 65406
Run options: --seed 60891
# Running:
.
Finished in 0.340621s, 2.9358 runs/s, 2.9358 assertions/s.
1 runs, 1 assertions, 0 failures, 0 errors, 0 skips
Adding The Blog App
The getting started guide has always outlined a simple blog application.
Adding the basic features to minime5:
rails generate controller Articles
rails generate model Article title:string text:text
rake db:migrate