Ruby on Rail
What is Ruby?
-
Ruby is a high-level interpreted programming language.
-
It's an object-oriented program.
-
It is open-source on web.
History
-
It was created in 1995.
-
Developed by Yukihiro Matsumoto in Japan.
Features
-
Ruby is a general-purpose programming language.
-
Ruby can easily be connected to DB2, MySQL, Oracle, and Sybase.
-
Ruby can embed to the HTML page.
-
Has rich libraries.
-
Cross-platform.
Ruby Installation
-
We can download the Ruby installer from its official site, https://www.ruby-lang.org/en/downloads/
-
Choose your OS and click on download button.
-
It contains Ruby language, an execution environment, documentation, developer kit & more.
-
Open the .exe installer file.
-
Make sure you tick the "Add Python 3. to PATH" checkbox and click on "Install Now",
-
We wrote the Hello World program in ruby.
-
Saved as HelloRuby.rb file name.
-
We can execute the Ruby file on command prompt by typing ruby HelloRuby.rb
-
But we build the enviroment for the Sublime Text editor for Ruby.
-
By pressing Ctrl + B, we got the result.
What is Ruby on Rails?
-
Is a server-side web application development framework.
-
Written in Ruby.
-
It supports MVC pattern to create web application.
History
-
Written by David Heinemeier Hansson.
-
In 2005.
Features
-
It is an open source Ruby framework for developing database-backed web applications.
-
Can write 10 times faster than Java Framework.
-
No compilation is required.
-
There is 2 guiding principle:
Ruby on Rails Principles:
Don't Repeat Yourself
(DRY)
-
Every code must have an unambiguous, single representation within the system.
-
A code will not repeat again.
Convention Over Configuration
(CoC)
-
It provides a different best way to do many things in a web application.
Ruby on Rail Environment
-
To develop a web-application environment, we need to have following installed on computer.:
-
Ruby
-
Ruby on Rails Framework
-
Database (MySQL)
-
Web Server (WEBrick)
-
Installing Ruby
-
We already installed Ruby in previous step.
Installing Rails
-
In Command Prompt, We can install Rails & its dependencies using the following command; gem intall rails
-
You need an internet connection for installing.
To install Rails
To check gem version
-
Type rails -v to check the Rails version.
To check Rails version
Installing Server
-
We can verify the Ruby on Rail installation.
-
To create a StoneProfits project rails new StoneProfits
To create a project
-
The new project is createcd on C:\Users\SPS\StonProfits .
-
Open the Command prompt on that directory.
-
To run WEBrick web server on our PC, type cd StoneProfits > rails server
To navigate our project folder
To run on WEBrick server
-
We can check the server on the browser by going localhost:3000
Installing Database
-
We have installed MySQL RDBMS for the database.
-
To install PostgreSQL, type gem install postgre
To install PostgreSQL database
Rails on MVC
-
Rails web application works on MVC.
-
Model, View & Controller are associated with some folder on local Ruby directory as ActiveRecord, ActionView & ActionController.​
MVC
Controller
-
It directs the traffic.
-
Querying the models for data.
-
Organizing that data
View
It is a presentation of data triggered by Controller. (AJAX, etc)
Model
Maintains relation between objects and the database and handles validation,
Creating Rails Web Application
-
Rails is a framework and set of helper scripts.
-
To start our Library System application, type rails new library on CMD.
The Hello World
-
Python is an interpreted programming language.
-
We need to write Python (.py) files in a text editor and then put those files into the python interpreter to be executed.
-
Where HelloWorld.py is the name of your python file.
-
We wrote the one line program in a text editor.