Rails Workshop 2

Transcript

1. Ruby
   Rails
   ON
   2
   Monday, February 27, 12
   

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2. About Me
   Mike Skalnik
   github.com/skalnik
   @skalnik
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3. Where did
   we stop?
   We have posts!
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4. ActiveRecord
   Associations
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5. 4 Kinds
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   has_one, has_many, habtm/has_many :through, belongs_to
   

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6. has_one
   Georgia Tech
   A School
   Buzz
   Mascot
   has_one
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7. has_one
   class School < ActiveRecord::Base
   has_one :mascot
   end
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8. has_many
   id title body
   1 First Post! …
   2 The Value of… …
   id author body post_id
   1 Mike … 1
   2 Eric … 1
   3 Kyle … 2
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9. has_many
   class Post < ActiveRecord::Base
   has_many :comments
   end
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10. belongs_to
    class Comment < ActiveRecord::Base
    belongs_to :post
    end
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11. belongs_to
    class Mascot < ActiveRecord::Base
    belongs_to :school
    end
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12. has_many :through
    has_and_belongs_to
    vs
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13. expose join table
    hide join table
    vs
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    Exposed as a model
    

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14. class Category < ActiveRecord::Base
    has_many :categorizations
    has_many :posts, :through => categorizations
    end
    class Categorization < ActiveRecord::Base
    belongs_to :post
    belongs_to :category
    end
    class Post < ActiveRecord::Base
    has_many :categorizations
    has_many :categories,
    :through => categorizations
    end
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    Allows for validations, along with attaching data to the association. How about Users with
    Ratings & Songs?
    

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15. vs
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16. class Post < ActiveRecord::Base
    has_and_belongs_to_many :categories
    end
    class Category < ActiveRecord::Base
    has_and_belongs_to_many :posts
    end
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    No touching the table, just a link. Still need to write migration though!
    

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17. Usage
    @post.comments #=> [#, …]
    @post.categories #=> [#, …]
    @comment.post #=> #
    @school.mascot #=> #
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18. $ terminal_time
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19. ActiveRecord
    Validations
    ✖ ✓
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    Not a full list, but the more common ones
    

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20. validates :terms,
    :acceptance => true
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    Accept TOS
    

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21. validates :password,
    :confirmation => true
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    confirm password
    

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22. validates :username,
    :exclusion =>
    { :in => [‘user’] }
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    reserved usernames
    

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23. validates :email,
    :format =>
    { :with => /.*@.*/ }
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    validate email format
    

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24. validates :size,
    :inclusion =>
    { :in =>
    [‘small’, …] }
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    size is in list
    

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25. validates :name,
    :length => {
    :minimum => 2,
    :maximum => 500,
    :in => 2..500,
    :is => 12
    }
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    Lots of options
    

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26. validates :points,
    :numericality => true
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27. validates :email,
    :presence => true
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    Ensure it’s there
    

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28. validates :email,
    :uniqueness => true
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    Ensure they haven’t registered before
    

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29. Usage
    @post.save #=> false if not valid
    @post.valid?
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30. More
    Resources
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    Not a full list, but the more common ones
    

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31. RailsGuides
    http://guides.rubyonrails.org
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    Not a full list, but the more common ones
    

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32. RailsCasts
    http://railscasts.com
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    Not a full list, but the more common ones
    

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33. Ruby Toolbox
    http://ruby-toolbox.com
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    Not a full list, but the more common ones
    

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34. Me
    hi@mikeskalnik.com
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    Not a full list, but the more common ones
    

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35. @
    Web
    Tech
    Innovators
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36. ATLRUG
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37. THANKS
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