Ruby on Rails Talk

Transcript

1. Ruby on Rails A demonstration of building a Ruby on Rails application from start to finish.
2. What is Ruby on Rails? • An open source full-stack web application framework • Ruby is a general purpose programming language which existed more than 10 years before Rails • Ruby on Rails is often called “Rails”
3. David Heinemeier Hansson • Author of Ruby on Rails • Framework released as open source July 2004 • Originally written for Basecamp • 37signals
4. Features • Ability to retrieve information from the web server • Query the database using ActiveRecord ORM layer • Dynamic finders • Scoping data • Render templates • Use routing system independent of web server • Organize application code using MVC architecture pattern • Database migrations • Scaffold controllers • Form validations
5. Features (Cont.) • Nested attributes • Polymorphism • Single table inheritance
6. [M]odel, [V]iew, [C]ontroller (MVC) • MVC architecture pattern used to organize application code
7. Model • Class definition of an object • Model name maps to table in database • Rails convention when naming a model
8. Controller • Responds to external requests from the web server to application. • Queries model for information and passes information on to the view • Controller action will not be accessible by an external request if it is not mapped to the Rails router.
9. View • Presentation layer used to output the results of the external web request. • Typically an erb file that outputs html at run- time.
10. Convention over Configuration • Developer only needs to specify unconventional aspects of the application. • Rail's conventions lead to less code and less repetition.
11. Don't Repeat Yourself (DRY) • Rapid development principle • Information is located in a single, unambiguous place.
12. Demonstration • Objective: Build a Ruby on Rails application • Theme: Blog application