Ruby API client

Author: OndraFiedler

Gemfile

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+source 'https://rubygems.org'
+
+gemspec

LICENSE.txt

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+The MIT License (MIT)
+
+Copyright (c) 2015 Ondřej Fiedler
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

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+# RecombeeApiClient
+
+A Ruby client for easy use of the [Recombee](https://www.recombee.com/) recommendation API.
+
+Documentation of the API can be found at [docs.recombee.com](https://docs.recombee.com/).
+
+## Installation
+
+Add this line to your application's Gemfile:
+
+```ruby
+gem 'recombee_api_client'
+```
+
+And then execute:
+
+    $ bundle
+
+Or install it yourself as:
+
+    $ gem install recombee_api_client
+
+## Examples
+
+### Basic example
+```ruby
+require 'recombee_api_client'
+include RecombeeApiClient
+
+# Prepare some items and users 
+NUM = 100
+my_users = (1..NUM).map { |i| "user-#{i}" }
+my_items = (1..NUM).map { |i| "item-#{i}" }
+
+#Generate some random purchases of items by users
+PROBABILITY_PURCHASED = 0.1
+my_purchases = []
+my_users.each do |user|
+  p = my_items.select { |_| rand(0.0..1.0) < PROBABILITY_PURCHASED }
+  p.each { |item| my_purchases.push('userId' => user, 'itemId' => item) }
+end
+
+# Use Recombee recommender
+client = RecombeeClient.new('client-test', 'jGGQ6ZKa8rQ1zTAyxTc0EMn55YPF7FJLUtaMLhbsGxmvwxgTwXYqmUk5xVZFw98L')
+begin
+  # Send the data to Recombee, use Batch for faster processing
+  puts 'Send users'
+  client.send(Batch.new(my_users.map { |userId| AddUser.new(userId) }))
+  puts 'Send items'
+  client.send(Batch.new(my_items.map { |itemId| AddItem.new(itemId) }))
+  puts 'Send purchases'
+  client.send(Batch.new(my_purchases.map { |p| AddPurchase.new(p['userId'], p['itemId'], 0) }))
+  
+  # Get recommendations for user 'user-25'
+  puts 'Recommend for a user'
+  recommended = client.send(UserBasedRecommendation.new('user-25', 5, 'rotationRate' => 0))
+  puts "Recommended items: #{recommended}"
+rescue ResponseError => e
+  puts e
+end
+```
+
+### Using property values
+```ruby
+#!/usr/bin/env ruby
+
+require 'recombee_api_client'
+include RecombeeApiClient
+
+NUM = 100
+PROBABILITY_PURCHASED = 0.1
+
+client = RecombeeClient.new('client-test', 'jGGQ6ZKa8rQ1zTAyxTc0EMn55YPF7FJLUtaMLhbsGxmvwxgTwXYqmUk5xVZFw98L')
+client.send(ResetDatabase.new)
+# We will use computers as items in this example
+# Computers have three properties 
+#   - price (floating point number)
+#   - number of processor cores (integer number)
+#   - description (string)
+
+# Add properties of items
+client.send(AddItemProperty.new('price', 'double'))
+client.send(AddItemProperty.new('num-cores', 'int'))
+client.send(AddItemProperty.new('description', 'string'))
+
+# Prepare requests for setting a catalog of computers
+requests = (1..NUM).map do |i|
+  SetItemValues.new(
+      "computer-#{i}", #itemId
+      #values:
+      { 
+        'price' => rand(15000.0 .. 25000.0),
+        'num-cores' => rand(1..8),
+        'description' => 'Great computer',
+        '!cascadeCreate' => true # Use !cascadeCreate for creating item
+                                 # with given itemId, if it doesn't exist
+      }
+    )
+end
+
+# Send catalog to the recommender system
+client.send(Batch.new(requests))
+
+# Prepare some purchases of items by users
+requests = []
+(1..NUM).map{|i| "computer-#{i}"}.each do |item_id|
+  user_ids = (1..NUM).map{|i| "user-#{i}"}
+  user_ids = user_ids.select { |_| rand(0.0..1.0) < PROBABILITY_PURCHASED }
+  # Use cascadeCreate to create unexisting users
+  user_ids.each { |user_id| requests.push(AddPurchase.new(user_id, item_id, 0, 'cascadeCreate' => true)) }
+end
+
+# Send purchases to the recommender system
+client.send(Batch.new(requests))
+
+# Get 5 recommendations for user-42, who is currently viewing computer-6
+recommended = client.send(ItemBasedRecommendation.new('computer-6', 5, 'targetUserId' => 'user-42') )
+puts "Recommended items: #{recommended}"
+
+# Get 5 recommendations for user-42, but recommend only computers that
+# have at least 3 cores
+recommended = client.send(
+  ItemBasedRecommendation.new('computer-6', 5, {'targetUserId' => 'user-42', 'filter' => "'num-cores'>=3"})
+  )
+puts "Recommended items with at least 3 processor cores: #{recommended}"
+
+# Get 5 recommendations for user-42, but recommend only items that
+# are more expensive then currently viewed item (up-sell)
+recommended = client.send(
+  ItemBasedRecommendation.new('computer-6', 5,
+    {'targetUserId' => 'user-42', 'filter' => "'price' > context_item[\"price\"]"})
+  )
+puts "Recommended up-sell items: #{recommended}"
+```
+
+### Exception handling
+
+For the sake of brevity, the above examples omit exception handling. However, various exceptions can occur while processing request, for example because of adding an already existing item, submitting interaction of nonexistent user or because of timeout.
+
+We are doing our best to provide the fastest and most reliable service, but production-level applications must implement a fallback solution since errors can always happen. The fallback might be, for example, showing the most popular items from the current category, or not displaying recommendations at all.
+
+Example:
+```ruby
+
+begin
+  recommended = client.send(
+  ItemBasedRecommendation.new('computer-6', 5,
+    {'targetUserId' => 'user-42', 'filter' => "'price' > context_item[\"price\"]"})
+  )
+rescue ResponseError => e
+  #Handle errorneous request => use fallback
+rescue ApiTimeout => e
+  #Handle timeout => use fallback
+rescue APIError => e
+  #APIError is parent of both ResponseError and ApiTimeout
+end
+```

Rakefile

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+require 'bundler/gem_tasks'
+require 'rspec/core/rake_task'
+
+RSpec::Core::RakeTask.new(:spec)
+
+task default: :spec

lib/recombee_api_client.rb

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+require 'recombee_api_client/version'
+require 'securerandom'
+require 'digest/hmac'
+require 'httparty'
+require 'json'
+require 'open-uri'
+require 'net/https'
+require 'timeout'
+
+require 'recombee_api_client/errors'
+Gem.find_files('recombee_api_client/api/*.rb').each { |path| require path }
+
+module RecombeeApiClient
+  class RecombeeClient
+    include HTTParty
+
+    def initialize(account, token, options = {})
+      @account = account
+      @token = token
+      @base_uri = options[:base_uri] ||= 'https://rapi.recombee.com'
+    end
+
+    def send(request)
+      @request = request
+      uri = request.path
+      uri.slice! ('/{databaseId}/')
+      uri = URI.escape uri
+      timeout = request.timeout / 1000
+      # puts uri
+      begin
+        case request.method
+        when :put
+          hmac_put(uri, timeout)
+        when :get
+          hmac_get(uri, timeout)
+        when :post
+          hmac_post(uri, timeout, request.body_parameters.to_json)
+        when :delete
+          hmac_delete(uri, timeout)
+        end
+      rescue Timeout::Error
+        fail ApiTimeout.new(@request)
+      end
+    end
+
+    private
+
+    def hmac_put(uri, timeout, options = {})
+      r = self.class.put(sign_url(uri), query: options, timeout: timeout)
+      check_errors r
+      r.body
+    end
+
+    def hmac_get(uri, timeout, options = {})
+      r = self.class.get(sign_url(uri), query: options, timeout: timeout)
+      check_errors r
+      JSON.parse(r.body)
+    end
+
+    def hmac_post(uri, timeout, options = {})
+      url = sign_url(uri)
+      # pass arguments in body
+      r = self.class.post(url, body: options, 
+                        headers: { 'Content-Type' => 'application/json' },
+                        timeout: timeout)
+      check_errors r
+      begin
+        return JSON.parse(r.body)
+      rescue JSON::ParserError
+        return r.body
+      end
+    end
+
+    def hmac_delete(uri, timeout, options = {})
+      r = self.class.delete(sign_url(uri), query: options, timeout: timeout)
+      check_errors r
+      r.body
+    end
+
+    def check_errors(response)
+      status_code = response.code
+      return if status_code == 200 || status_code == 201
+      fail ResponseError.new(@request, status_code, response.body)
+    end
+
+    # Sign request with HMAC, request URI must be exacly the same
+    # We have 30s to complete request with this token
+    def sign_url(req)
+      uri = "/#{@account}/#{req}"
+      time = hmac_time(uri)
+      sign = hmac_sign(uri, time)
+      @base_uri + uri + time + "&hmac_sign=#{sign}"
+    end
+
+    def hmac_time(uri)
+      res = (uri.include? '?') ? '&' : '?'
+      res << "hmac_timestamp=#{Time.now.utc.to_i}"
+    end
+
+    def hmac_sign(uri, time)
+      url = uri + time
+      Digest::HMAC.hexdigest(url, @token, Digest::SHA1)
+    end
+  end
+end

lib/recombee_api_client/api/add_bookmark.rb

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+#
+# This file is auto-generated, do not edit
+#
+
+module RecombeeApiClient
+  require_relative 'request'
+  require_relative '../errors'
+  
+  ##
+  #Adds a bookmark of a given item made by a given user.
+  #
+  class AddBookmark < ApiRequest
+    attr_reader :user_id, :item_id, :timestamp, :cascade_create
+    attr_accessor :timeout
+  
+  ##
+  # * *Required arguments*
+  #   - +user_id+ -> User who bookmarked the item
+  #   - +item_id+ -> Bookmarked item
+  #   - +timestamp+ -> Unix timestamp of the bookmark. If you don't have the timestamp value available, you may use some artificial value, such as 0. It is preferable, however, to provide the timestamp whenever possible as the user's preferences may evolve over time.
+  #
+  # * *Optional arguments (given as hash optional)*
+  #   - +cascadeCreate+ -> Sets whether the given user/item should be created if not present in the database.
+  #
+    def initialize(user_id, item_id, timestamp, optional = {})
+      @user_id = user_id
+      @item_id = item_id
+      @timestamp = timestamp
+      @cascade_create = optional['cascadeCreate']
+      @optional = optional
+      @timeout = 1000
+      @optional.each do |par, _|
+        fail UnknownOptionalParameter.new(par) unless ["cascadeCreate"].include? par
+      end
+    end
+  
+    # HTTP method
+    def method
+      :post
+    end
+  
+    # Values of body parameters as a Hash
+    def body_parameters
+      p = Hash.new
+      p['userId'] = @user_id
+      p['itemId'] = @item_id
+      p['timestamp'] = @timestamp
+      p['cascadeCreate'] = @optional['cascadeCreate'] if @optional['cascadeCreate']
+      p
+    end
+  
+    # Values of query path parameters as a Hash.
+    # name of parameter => value of the parameter
+    def query_parameters
+      params = {}
+      params
+    end
+  
+    # Relative path to the endpoint
+    def basic_path
+      "/{databaseId}/bookmarks/"
+    end
+  
+    # Relative path to the endpoint including query parameters
+    def path
+      p = "/{databaseId}/bookmarks/"
+      p
+    end
+  end
+end