RubyConf 2014: Rapidly Mapping JSON/XML APIs in Ruby

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Rapidly Mapping APIs

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github.com/CodingZeal/RubyConf2014

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Consume Coerce Consolidate

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Consume Coerce Consolidate

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Connection: Relationship Manager

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Connection Resource HTTP GET/POST

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https://www.googleapis.com/civicinfo/v1/elections?key=

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https://www.googleapis.com/civicinfo/v1/elections?key=

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class Connection include HTTParty DEFAULT_API_VERSION = "2" DEFAULT_BASE_URI = "https://www.googleapis.com/civicinfo" base_uri DEFAULT_BASE_URI # ... end

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class Connection # ... def initialize(options={}) @api_version = options.fetch(:api_version, DEFAULT_API_VERSION) end # ... endd

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https://www.googleapis.com/civicinfo/v1/elections?key=

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class Connection include HTTParty DEFAULT_API_VERSION = "2" DEFAULT_BASE_URI = "https://www.googleapis.com/civicinfo" DEFAULT_QUERY = {} base_uri DEFAULT_BASE_URI def initialize(options={}) @api_version = options.fetch(:api_version, DEFAULT_API_VERSION) @query = options.fetch(:query, DEFAULT_QUERY) end def query(params={}) @query.update(params) end # ... end

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connection = Connection.new( api_version: “2” ) connection.query( key: “qwerty12345” )

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Client: Routing and Collection

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Connection Application Client

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class Client def initialize(options={}) @connection = options.fetch(:connection) @routes = options.fetch(:routes) end end

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https://www.googleapis.com/civicinfo/v1/elections?key=

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# GET /elections { elections: { method: "get", path: "/elections" } }

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connection = Connection.new connection.query( key: “qwerty12345” ) routes = { elections: { method: "get", path: "/elections" } } client = Client.new(connection: connection, routes: routes)

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client.elections # ???

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class Client # ... def method_missing(method) # => :elections route_map = routes.fetch(method) http_method = route_map.fetch(:method) # => "get" relative_path = route_map.fetch(:path) # => "/elections" # call the connection for records @connection.send(http_method, relative_path) end # ... end

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# client.elections { "kind" => "civicinfo#electionsQueryResponse", "elections" => [{ "id" => "2000", "name" => "VIP Test Election", "electionDay" => "2015-06-06" }] }

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Consume Coerce Consolidate

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Representation: Entity mapping

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Application Client Representation Class Instance Hash Instance

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Representation { “id" => "2000", “name" => "VIP Test Election", “electionDay" => "2015-06-06" } #

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require "ostruct" class Representation < OpenStruct end

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Consume Coerce Consolidate

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require "ostruct" class Representation < OpenStruct attr_reader :parent, :children def initialize(representation={}, parent=nil) super(representation) @parent = parent @children = [] bind_parent(parent) represent_children(representation) end # ... end

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class Representation < OpenStruct # ... def represent(key, collection, parent=nil) collection = Array(collection) collection.map do |item| definition_class = definition_class_for_key(key) definition_class.new(item, parent) end end def definition_class_for_key(key) definition_class = convert_key_to_class_string(key) Object.const_get(definition_class) rescue NameError Object.const_set(definition_class, Representation) end # ... end

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class Election < Representation # ... end

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representation = Representation.new(client.elections)

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{ "kind" => "civicinfo#electionsQueryResponse", "elections" => [{ "id" => "2000", "name" => "VIP Test Election", "electionDay" => "2015-06-06" }] }

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Mutability

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{ "id" => "2000", "name" => "VIP Test Election", "electionDay" => "2015-06-06", "locations" => { "street"=> "111 Main St.", "city" => "Medford", "state" => "Oregon", "zipcode" => "97501" } }

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class Election < Representation def address [self.street, self.city, self.state, self.zipcode].join(' ') end end

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class Election < Representation include ActiveModel::Validations end

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Flexibility

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Representable Take an object and decorate it with a representer module, render a JSON, XML or YAML document from that object. You can also use representers to parse a document and create or populate an object. https://github.com/apotonick/representable#representable

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@AdamCuppy

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Thank You!

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Catch Changes Release Patches

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{ "kind" => "civicinfo#electionsQueryResponse", "elections" => [{ "id" => "2000", "name" => "VIP Test Election", "electionDay" => "2015-06-06", "locations" => { "address" => "111 Main St. Medford, Oregon 97501" } },{ "id" => "2000", "name" => "VIP Test Election", "electionDay" => "2015-06-06" }] }

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elections[0][“locations”][“address”] elections[1][“locations”][“address”]

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elections.rb:12:in `': undefined method `[]' for nil:NilClass (NoMethodError)

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elections[1][“locations”]

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elections[1].fetch(“locations”)

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elections.rb:12:in `fetch': key not found: "location" (KeyError)

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.fetch(“locations”, { address: “Not determined” })