Creating a web application is no easy task, I mean not for your average beginner, and If you are like me you might have a hard time trying to figure out where to begin. So where do we begin or better yet where did I begin?
1. NUMERO UNO
If your anything like me, you’ll want to cut out as much monotonous work as possible this includes building a File structure. Luckily for us, there is a ruby gem for that. corneal will do the bulk of the work for us. Just like any other gem, you’ll want to install said gem like so:
gem install corneal
#run
corneal new App-Name
bundle install
This should give access to a ton of important gems that we’ll need for our app such as activerecords, bcrypt, rake, and, most importantly Sinata and, more; check out the corneal link above for full details.
Also thanks to corneal our we have a file structure that should look something like this
├── config.ru
├── Gemfile
├── Gemfile.lock
├── Rakefile
├── README
├── app
│ ├── controllers
│ │ └── application_controller.rb
│ ├── models
│ └── views
│ ├── layout.erb
│ └── welcome.erb
├── config
│ ├── initializers
│ └── environment.rb
├── db
│ └── migrate
├── lib
│ └── .gitkeep
└── public
| ├── images
| ├── javascripts
| └── stylesheets
| └── main.css
└── spec
├── application_controller_spec.rb
└── spec_helper.rb
NEXT
Now we can start by building out our migrations table.
first, you’ll want to start with our has_many and belongs to relationship, It is important to remember that, has_many is an activerecords method. Let say that we were building a simple user application. we could create our rake commands such as:
rake db:create_migration NAME=user
rake db:create_migration NAME=Item
This should give us two migrations that look like this
#db/migrate/10001_create_users.rb
class CreateUsers < ActiveRecord::Migration
def change
create_table :user do |t|
t.timestamps null: false
end
end
end
#db/migrations/10002_create_Items.rb
class CreateItems < ActiveRecord::Migration
def change
create_table :user do |t|
t.timestamps null: false
end
end
end
we’ll want to build out the the table with the appropriate colums like so:
#db/migrate/10001_create_users.rb
class CreateUsers < ActiveRecord::Migration
def change
create_table :user do |t|
t.string :user_name
t.email
t.password_digest
t.string :item_name
t.timestamps null: false
end
end
end
#db/migrations/10002_create_Items.rb
class CreateItems < ActiveRecord::Migration
def change
create_table :user do |t|
t.string :name
t.integer :item_id
t.timestamps null: false
end
end
end
Now in our models class, we want to make our association that way we can use association methods that we inherit from ActiveRecord.
#app/model/user.rb
class User
has_many :items
end
#app/model/item.rb
class Item
belongs_to :user
end
Now, in a real-world situation, we wouldn’t want to do something like “user has_many: through: :user_items” but for this demonstration we’ll keep it pretty simple.
and Then
Now after running rake migrate we can start building our routes lets start with the login process
authentication
we can’t very well build an application that just allows our user’s password to be passed around with no security. so we’ll use some validation methods inherited from active records
#app/model/user.rb
class User
has_many :items
has_secure_password #mehtod, for salting our password aka password digest
validates :user_name, :email, presence: true, uniqueness: true
#validates user information to make sure it is "valid"
validates :password, presence: true
validates :password_confirmation, confirmation: true
end
#app/model/item.rb
class Item
#for this example we won't need to validate our belongs_to method
belongs_to :user
end
require './config/environment'
require 'sinatra/flash'
class ApplicationController < Sinatra::Base
configure do
set :public_folder, 'public'
set :views, 'app/views'
enable :sessions #this will set a session so that we can store the user id in a hash and grab the current_user's ID
register Sinatra::Flash #this is so we can display error messages to the user.
set :session_secret, "no_peeping_jerrys" #makes** it **harder** for **someone to create a fake session_id and hack into your site** without signing up or signing in.
end
get "/" do
erb :index
end
helpers do
def logged_in? # checks to see if user is a user is logged in
!!session[:user_id]
end
def current_user #returns true if the user making changes is the current user.
user.find(session[:user_id])
end
end
end
This will All of our classes in our “models” folder will inherit this class
Now we can build our user and items Route :
class usersController < ApplicationController
get '/signup' do #renders the signup page for the client
if !logged_in? #checks to make sure they are not already logged in
erb :'/users/new.html'
else
redirect to '/users'
end
end
post '/signup' do
@user = User.new(name:#obj information goes here)
if @user.save # if true
session[:user_id] = @user.id #sets the id attribute to be equal to session id
redirect to "users/#{@user.id}" #send to a spicific user page
end
end
get '/login' do #if the user has an existing account this renders the login
if !logged_in?
erb:'users/index.html'
else
redirect to'/users'
end
end
post '/login' do #this will be passed into params so we can minuplate in our controller with "post"
@user = User.find_by(user_name: params[:user_name]) #AR dynamic method allows us to grab the user by attribute input
if @user && @user.authenticate(params[:password])
session[:user_id] = @user.id
redirect to "/users/#{@user.id}"
else
redirect to '/login'
end
end
get '/logout' do
if logged_in?
session.clear #clears session when the user would like to leave
redirect to '/'
end
end
end
This will give us access to all the user’s via instance variable
class ItemsController < ApplicationController
get "/items/new" do
erb :"/items/new.html"
end
# POST: /items
post "/items" do
params.delete_if {|p| p == "submit"}
if !item.find_by(name: params[:name])
@item = item.new(params)
@item.save
current_user.items << @item
current_user.save
redirect to "/items/#{@item.id}"
end
end
Viola, now you have the start of a working web app Congrats!! Now I know there is a lot of unpacking to do here but, unpacking and, dissecting is our jobs its what, I believe to be a good engineer in a general sense, so if your reading this and you find yourself overwhelmed, just keep in mind that this is how you truly learn to understand code.
If you would like to view a Sinatra project that I built using this GoRobo
RESOUCES