Alexa-rails

alexa-rails is a ruby gem which is a mountable rails engine that will add abilities to your Ruby on Rails application to handle Amazon alexa requests and responses.

Intallation/Usage

Do the usual by adding the following to your Gemfile:

gem 'alexa-rails'

Migrations

The gem provides migrations that are needed to use few features of the gem. For example: Saving or reading the user's skill usage count. To generate the migrations, run the following

$ rails generate alexa:migrations
$ rake db:migrate

Configuration

Add config/initializers/alexa.rb and add the following configuration

    Alexa.configure do |config|
      # Location permissions type
      config.location_permission_type = :country_and_postal_code # or full_address

      # Default title used on the display cards for your skill
      config.default_card_title = "My Alexa skill"

      # Add ID of your skills. Used for request verification
      config.skill_ids = [
        "amzn1.ask.skill.xxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx"
      ]
    end

Mount the engine for routes handling in your routes

  # config/routes.rb

  Rails.application.routes.draw do
    ...
    mount Alexa::Engine, at: "/alexa"
  end

This will make you Rails app accept POST requests from Alexa at

https://<your-domain>/alexa/intent_handlers

This has to be provided as the HTTPS endpoint URL for the skill.

Request handling

To handle an intent, you will have to create an intent handler class. For example, if your intent is named PlaceOrder, you will have to create the following file under you app/lib/alexa/intent_handlers directory.

module Alexa
  module IntentHandlers
    class PlaceOrder < Alexa::IntentHandlers::Base
      def handle
        run_callbacks :handle do
          ...
          response # intent handlers should always return the +response+ object
        end
      end
    end
  end
end

All intent handlers should contain a #handle method that has required logic as to how to handle the intent request. For example, adding session variables, setting response to elicit slots, delegate etc.

Note: #handle method should always return the response object. response object in available in the scope of #handle.

See [Handling Amazon's Built-in Intents / Other request types] section to see how to handle Amazon's built-in intent and other requests types.

Adding session variable:

session.merge!(my_var: value)

# Accesssing session variable
session[:my_var]

Slot elicitations

Depending on your conditions, you can set the reponse to elicit a specific slot and the respecitve views are used.

response.elicit_slot!(:SlotName)

Delegate response

#handle is expected to return an instance of Alexa::Response or its subclasses. In normal cases, the response object is returned. In cases where the slots elicitation is delegated to alexa, an instance of Alexa::Responses::Delegate has to be returned.

  def handle
    run_callbacks :handle
      ...
      return Alexa::Responses::Delegate.new
    end
  end

Views

The content for SSML and display cards is not set in the intent handler classes. We follow rails convention and expect all response content for intents to be in their respective default view files.

Also, the views are context locale dependant.

Given an intent named PlaceOrder, you view files would be

• SSML: views/alexa/en_us/intent_handlers/place_order/default.ssml.erb
• Card: views/alexa/en_us/intent_handlers/place_order/default.text.erb

In case of slot elicitations, follow a similar convention but make sure you name the ssml and text files with the same name as the slot that is being elicited. For example, in the PlaceOrder intent, the elicatation for Address slot would have the following views

• SSML: views/alexa/en_us/intent_handlers/place_order/elicitations/address.ssml.erb
• Card: views/alexa/en_us/intent_handlers/place_order/elicitations/address.text.erb

Render custom template instead of default

If you wish to force the response object to take contents from a different template file instead of default.*.erb, pass the custom filename with Alexa::Response#with(template: ).

For example: Instead of default, if you wish to render the contents of no_results.ssml.erb and no_results.text.erb, return the response by forcing the template with the following:

  def handle
    ...
    return response.with(template: :no_results)
  end

and make sure you add your contents in the no_results.*.erb files in your intent handlers' views' directory.

SSML

Re-prompts

By default, there is no re-prompt SSML is added to the response. However, re-prompt SSML can be set in the ssml view of the intent response or a slot elicitation view with a content_for :repromt_ssml like this:

What is your address?

<% content_for :repromt_ssml do %>
  Where would you like the pizza to be delivered?
<% end %>

Cards

Type & Title

By default, the card type is set to Simple. To change the card type and title, use the content_for blocks in the text view file for the response as follows:

<% content_for :card_type do %>
  Simple
<% end %>
<% content_for :card_title do %>
  Get your pizza
<% end %>

Permission cards

To render a permission card. Use ask_for_permissions_consent as the card_type and provide the scope in permissions_scope content_for block. Following is an example for Device address permission card.

<% content_for :card_type do %>
  ask_for_permissions_consent
<% end %>

<% content_for :permissions_scope do %>
  read::alexa:device:all:address
<% end %>

Note: The permission card should not have any other content other than the content for card_type and permissions_scope.

Handling Amazon's Built-in Intents / Other request types

Requests for Amazon's built-in intents and other request types are also handled with intent handlers. Below is the mapping for every request type and respective intent handler classes. These intent handlers are not included in the gem as they are a but specific to the application. Refer to the table below and implement the intent handlers.

Built-in Intents:

Intent name	Handler class
AMAZON.CancelIntent	Alexa::IntentHandlers::GoodBye
AMAZON.StopIntent	Alexa::IntentHandlers::GoodBye
AMAZON.HelpIntent	Alexa::IntentHandlers::Help

Other request types:

Request type	Handler class
Launch request	Alexa::IntentHandlers::LaunchApp
Session end request	Alexa::IntentHandlers::SessionEnd

Installation

Add this line to your application's Gemfile:

gem 'alexa'

And then execute:

$ bundle

Or install it yourself as:

$ gem install alexa

Contributing

Contribution directions go here.

License

The gem is available as open source under the terms of the MIT License.