JSON?

• JavaScript Object Notation
• A datastructure for talking between servers/clients/other servers
• Key value pairs
• Universal, straightforward, human readable.

{
  "key1": "value1",
  "key2": 2,
  "key3": {
    "key3a": "nested"
  }
}

      

JSON Template?

• Build a sensible format for handling JSON
• Is treated a bit like a view
• Gives a handy DSL
• Only exposes the data you want

RABL

• Ruby API Builder Language
• gem 'rabl'
• Sinatra/Padrino : Rabl.register!
• Just call render from controller

RABL Template

# app/views/posts/index.rabl
collection @posts
attributes :id, :title, :subject
child(:user) { attributes :full_name }
node(:read) { |post| post.read_by?(@user) }

      

Naming

object @user => :person
# => { "person" : { ... } }
collection @users => :people
# => { "people" : [ { "person" : { ... } } ] }
collection @users, root: "people", object_root: "user"
# => { "people" : [ { "user" : { ... } } ] }

      

Attributes/Blocks

attributes :bar => :baz, :dog => :animal
# => # { baz : , animal :  }

node :full_name do |u|
  u.first_name + " " + u.last_name
end

      

Partials

node :location do
  { :city => @city, 
  :address => partial("users/address", :object => @address) }
end

      

Deep Nesting

# app/views/quizzes/show.json.rabl
object @quiz
attribute :title
child :questions do
  attribute :caption
  child :answers do
    # Use inheritance to reduce duplication
    extends "answers/item"
  end
end

      

Alternatives

• JSONify
• Jbuilder
• RepresentationView
• Active Model Serializers

Advantages

• A single place to check your api format
• Tidies up your controllers
• Stops 'munging' of data in controllers
• Quick api specific changes.

Questions?

@atleastimtrying