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
   

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2. Miguel Pinto
   Fernando Mendes
   twitter: fribmendes
   github: frmendes
   github: miguelpinto98
   skype: miguelpinto.98
   

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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
   

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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
   

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6. Rails is Ruby
   

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7. Ruby is NOT Java
   Object oriented
   Testable
   Programmer happiness
   Everything is an object
   “So beautiful, tears are shed” _why, the lucky stiff
   

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8. Meet Matz
   Matz Not Matz
   

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9. Hello world!
   Ruby is all about idiomatic code
   We do not require parentheses
   

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10. Duck typing
    “If it walks like a duck, swims like a
    duck and quacks like a duck, it’s
    probably a duck.”
    

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11. Idiomatic ifs
    No curly brackets!
    No annoying ;
    One liners!
    Easy to read!
    

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12. Idiomatic ifs
    btw, this is our string
    interpolation
    

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13. Idiomatic ifs
    You can put this in the one-
    liner syntax
    

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14. Methods
    

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15. Methods
    Wait a second, where are we
    returning the values!?
    

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16. Methods
    Returns the last interpreted expression
    Ruby is smart
    Default values
    

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17. Classes
    Creates new instance with
    Elevator.new(weight, capacity)
    Translates
    to
    

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18. Classes
    Operator override just feels
    more natural.
    If you don’t like it, we also
    have Object#eql? and
    Object#equal?
    

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19. Classes
    Also, surprise surprise!
    This code has a trap. Can
    you find it?
    

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20. Classes
    Remember that the last
    evaluated expression is the
    one that gets returned?
    

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21. Classes
    Only this is going to get
    returned.
    If we wanted to write the correct method
    we would have to use the && operator.
    

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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
    

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23. Classes
    class variable
    class method
    

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24. Blocks and High Order Functions
    Multi-line syntax
    One-line syntax
    

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25. Blocks and High Order Functions
    x is unchanged
    

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26. Blocks and High Order Functions
    x is unchanged
    x is changed
    Ruby convention:
    ! ending methods change the object
    ? ending methods return a boolean
    

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27. Symbols
    Strings assign
    different objects
    

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28. Symbols
    Symbols are always
    the same
    

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29. Wat the wtf is MVC
    

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30. Short answer:
    

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31. Not so short answer:
    

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32. My first app
    

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33. rails new project
    

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34. /app
    ..../controller
    ..../helpers
    ..../models
    ..../views
    ....../layouts
    /bin
    /config
    /db
    /doc
    /lib
    /log
    /public
    /test
    /tmp
    /vendor
    

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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
    

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36. Gemfile
    bundle install
    

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37. Bringing up the server
    rails server
    Check it for yourself: go to localhost:3000
    

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38. Checking the console
    rails console
    

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39. rails generate scaffold User username:string name:string
    

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40. Scaffolding
    rails generate scaffold User username:string name:string
    model name
    

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41. Scaffolding
    rails generate scaffold User username:string name:string
    attribute name
    

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42. Scaffolding
    rails generate scaffold User username:string name:string
    attribute type
    

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43. Views
    Under app/views//
    

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44. Views
    Under app/views//
    By default, Rails uses embedded Ruby .html.erb
    

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45. Views
    Under app/views//
    By default, Rails uses embedded Ruby .html.erb
    Have access to the instance variables created by the controller.
    

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46. Into the CRUD
    Create
    Read
    Update
    Delete
    

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47. Models
    User.new(username: “frmendes”, name: “Fernando Mendes”)
    

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48. User.all User.count
    Models
    

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49. User.new(username: “frmendes”, name: “Fernando Mendes”).save
    Models
    

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50. User.create(username: “codeweek”, name: “at DI”)
    Models
    

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51. User.find(1) User.find_by(username: “frmendes”)
    Models
    

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52. Controllers and Routes
    

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53. Migrations
    

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54. Migrations
    rails generate migration AddIndexToUsers
    

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55. Validations
    

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56. Ruby Make
    rake db:{drop,migrate}
    You better be
    f*cking careful!!1!
    

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57. Relationships
    

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58. Miguel Pinto
    Fernando Mendes
    twitter: fribmendes
    github: frmendes
    github: miguelpinto98
    skype: miguelpinto.98
    

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