Riding Rails

Brief introduction to Ruby and Rails for a workshop that took place during CodeWeek @ DI in University of Minho

Transcript

1. Riding Rails Code Week @ DI
2. Miguel Pinto Fernando Mendes twitter: fribmendes github: frmendes github: miguelpinto98 skype: miguelpinto.98
4. gem install rails If you have Ruby installed: To install Ruby on OS X: 1. Install Homebrew 2. brew install rbenv ruby-build To install Ruby on Linux: \curl -sSL https://get.rvm.io | bash -s stable --ruby --rails
5. What I will be talking about 1. Ruby syntax 2. Basic Rails What I won’t be talking about: 1. Design 2. Patterns 3. Good practices Basic concepts = slides Everything else = examples
6. Rails is Ruby
7. Ruby is NOT Java Object oriented Testable Programmer happiness Everything is an object “So beautiful, tears are shed” _why, the lucky stiff
8. Meet Matz Matz Not Matz
9. Hello world! Ruby is all about idiomatic code We do not require parentheses
10. Duck typing “If it walks like a duck, swims like a duck and quacks like a duck, it’s probably a duck.”
11. Idiomatic ifs No curly brackets! No annoying ; One liners! Easy to read!
12. Idiomatic ifs btw, this is our string interpolation
13. Idiomatic ifs You can put this in the one- liner syntax
14. Methods
15. Methods Wait a second, where are we returning the values!?
16. Methods Returns the last interpreted expression Ruby is smart Default values
17. Classes Creates new instance with Elevator.new(weight, capacity) Translates to
18. Classes Operator override just feels more natural. If you don’t like it, we also have Object#eql? and Object#equal?
19. Classes Also, surprise surprise! This code has a trap. Can you find it?
20. Classes Remember that the last evaluated expression is the one that gets returned?
21. Classes Only this is going to get returned. If we wanted to write the correct method we would have to use the && operator.
22. Classes public: default value, accessed by anyone protected: method can be accessed by the class or subclasses private: method can only be accessed by the class
23. Classes class variable class method
24. Blocks and High Order Functions Multi-line syntax One-line syntax
25. Blocks and High Order Functions x is unchanged
26. Blocks and High Order Functions x is unchanged x is changed Ruby convention: ! ending methods change the object ? ending methods return a boolean
27. Symbols Strings assign different objects
28. Symbols Symbols are always the same
29. Wat the wtf is MVC
30. Short answer:
31. Not so short answer:
32. My first app
33. rails new project
34. /app ..../controller ..../helpers ..../models ..../views ....../layouts /bin /config /db /doc /lib /log /public /test /tmp /vendor
35. External libraries (gems) are imported into your project. Can have specified versions, minimum version, etc. Can Should be divided into groups Not necessarily Rails-exclusive Gemfile
36. Gemfile bundle install
37. Bringing up the server rails server Check it for yourself: go to localhost:3000
38. Checking the console rails console
39. rails generate scaffold User username:string name:string
40. Scaffolding rails generate scaffold User username:string name:string model name
41. Scaffolding rails generate scaffold User username:string name:string attribute name
42. Scaffolding rails generate scaffold User username:string name:string attribute type
43. Views Under app/views/<controller_name>/<controller_method>
44. Views Under app/views/<controller_name>/<controller_method> By default, Rails uses embedded Ruby .html.erb
45. Views Under app/views/<controller_name>/<controller_method> By default, Rails uses embedded Ruby .html.erb Have access to the instance variables created by the controller.
46. Into the CRUD Create Read Update Delete
47. Models User.new(username: “frmendes”, name: “Fernando Mendes”)
48. User.all User.count Models
49. User.new(username: “frmendes”, name: “Fernando Mendes”).save Models
50. User.create(username: “codeweek”, name: “at DI”) Models
51. User.find(1) User.find_by(username: “frmendes”) Models
52. Controllers and Routes
53. Migrations
54. Migrations rails generate migration AddIndexToUsers
55. Validations
56. Ruby Make rake db:{drop,migrate} You better be f*cking careful!!1!
57. Relationships
58. Miguel Pinto Fernando Mendes twitter: fribmendes github: frmendes github: miguelpinto98 skype: miguelpinto.98