In the next 3 chapters im going dive into what makes Ruby on Rails special, the MVC(Model, View , Controller) concept.
it’s where we define our noun, e.g. a collection of cars have a list of attributes like name, weight, color, fabricate etc. It defines our stuff. It’s a description of what it is and what we can do with it.
To create a Model we type: ( in the home directory of our app )
rails generate model User name:string age:integer
# here we use the “generate” command to guess what, generate the Model with the name of User and with the attributes of name:string and age:integer.
String = all sort of text, contains of letters and numbers. A sentence like “Hello World!” is a string and often enclosed by “…” .
Integer = Numbers like 0 – 10.
The generation makes a migration file and a definition of the Model in our app. To add the migration to our database we have to run:
rake db:migrate #or
Migration = It’s an instruction to update our database table
To define our User Model we can edit our user.rb file with basic methods like:
class User < ActiveRecord::Base #the class of User inherits from ActiveRecord Library
def how_old #defining our method how_old to check how old the User is
“I’m ” + self.age.to_s + ‘years old’ #making a string
end #ending our block of code
If we enter the Rails console by opening the command line and typing:
we can first make a new User with:
Mark = User.new(name: “Mark” , age: ’26’)
and call the newly made method: how_old on it with:
and it will print out:
“I’m 26 years old”
This is just a quick example of how to create and define a model. Theres alot more to it, which im going to talk about soon.