Ruby on Rails Tutorial

This is a working tutorial for setting up your first Ruby App.

Necessary ingrediants

• Ruby
• Bundler
• mySql

Install Ruby

I am using rbenv and ruby-build. Others may use rvm or some other Ruby version manager.

To get these tools, I'm using homebrew

Install rbenv

brew install rbenv

brew install ruby-build

Install Ruby

Check what the latest version is either on Ruby-lang or through rbenv

rbenv install --list

Then install whichever version you want:

rbenv install 2.3.1

You will need to run rehash to install shims.

rbenv rehash

And then set global ruby to use whichever version you want.

rbenv global 2.3.1

Install Rails and Bundler

Bundler is the best way to manage your Gemfile

gem install bundler

You probably don't need docs cause they're much better online.

gem install rails --no-ri --no-rdoc

Install MySQL

Using cloud9 Follow this guide On Mac, I'm using homebrew

brew install mysql

Make sure you run mysql before starting the app

mysql.server start

Install the gems

bundle install

Run the demo app

rails server

Or in cloud9

rails s -b $IP -p $PORT -e c9

Migrating Database

To get the same database as is in a certain project, follow the instructions here.

Navigating this tutorial

Most of the commits represent a lesson, to follow along go through each of the commits to see what the lesson entails. Most of them are explained pretty well through the commit message.

rails Generate

One of the most powerful features of Rails is the ability to generate scaffolding.

To see what kind of generation you can perform

rails generate

Generate new controller/views

rails generate controller <controllerName> <viewName>

Database Initialization

Create a database in mysql

1. Login

mysql -u root

2. Create database

CREATE simple_cms_development;

3. Switch to new database

USE simple_cms_development;

4. Create a new user and password so you don't have to use root for everything.

CREATE USER 'whateverUsernameYouDesire'@'localhost';

Give permissions to user.

GRANT ALL PRIVILEGES ON simple_cms_development.*
TO 'whateverUsernameYouDesire'@'localhost'
IDENTIFIED BY 'whateverPasswordYouDesire';

To grant permissions to everything user

GRANT ALL PRIVILEGES ON *.*
TO 'whateverUsernameYouDesire'@'localhost'
IDENTIFIED BY 'whateverPasswordYouDesire';

You can now check the privileges of that user.

SHOW GRANTS FOR whateverUsernameYouDesire@localhost;

5. Exit the application and sign in with new user and connect to simple_cms_development database.

mysql -u whateverUsernameYouDesire -p simple_cms_development

Creating db schema dump

This will create a schema dump file: 'db/schema.rb' Even if you don't have any tables, this command can be used to ensure the database configuration in database.yml is correct. If not, it will throw an error.

rake db:schema:dump

Working with rake

Rake helps perform tasks by running scripts. You can use it to perform many types of tasks by through rails, as well as add your own custom scripts by adding new ones to /Rakefile. To see what kind commands are available in the root of your application types

rake -T

To drill down into rake db tasks,

rake -t db

You can also add an environmental variable to the rake command to specify certain conditions. The most common one being RAILS_ENV=production

rake db:schema:dump RAILS_ENV=production'

or for cloud9,

rake db:schema:dump RAILS_ENV=c9'

Migrations

Migrations are Ruby's way of interacting with the database schema using Ruby code.

Generate Migrations

rails generate migration MyMigrationName

Generate Model

Generating a model will also generate an associated migration. In this case the associated migration would be named with the timestamp and then _create_model_names.rb

rails generate model ModelName

Running our migrations

For any of the rake commands in cloud9, append RAILS_ENV=c9. Rake will create the tables we have specified in our migration files, and add entries for each of the migrations keyed by their timestamp.

rake db:migrate

View the migrations in the database under the schema_migrations table.

SELECT * FROM schema_migrations;

Taking down migrations

This will take down all of your migrations.

rake db:migrate VERSION=0

Get the status of the migrations

To see if migrations are up or down

rake db:migrate:status

VERSIONs

You can go through the migrations sequentially by using VERSION= of whatever version. So if you only wanted to run the Create users migration, you'd enter

rake db:migrate VERSION=20160917170621

Rails Console

From the root of your application, you can perform tasks using your application to models and the database through rails console

rails console

Or for short

rails c

To specify enironment:

rails console c9

For more info, check out Rails Console.

Controllers and CRUD

Controllers and crud information can be found here.