@jargon/actions-on-google

Jargon SDK for Google Assistant Actions (nodejs)

The Jargon SDK makes it easy for skill developers to manage their runtime content, and to support multiple languages from within their skill.

Need help localizing your skills to new languages and locales? Contact Jargon at [e-mail].

Requirements

This version of the SDK works with Google Assistant actions that are built using the Actions on Gooogle support library.

The Jargon SDK makes use of Javascript features supported by Node version 8 and later. When deploying on Google / Firebase cloud functions make sure you're selecting the appropriate engine in your package.json:

  "engines": {
    "node": "8"
  }

Like the Actions on Goolge support library, the Jargon SDK is built using TypeScript, and includes typing information in the distribution package.

Core concepts

Content resources and resource files

Content resources define the text that your skill outputs to users, via Alexa's voice, card content, or screen content. It's important that these resources live outside of your skill's source code to make it possible to localize them into other languages.

The Jargon SDK expects resource files to live in the "resources" subdirectory within your lambda code (i.e., skill_root/lambda/custom/resources). Each locale has a single resouce file, named for that locale (e.g., "en-US.json").

Resource files are JSON, with a single top-level object (similar to package.json). The keys within that object are the identifiers you'll use to refer to specific resources within your source code. Nested objects are supported to help you organize your resources.

{
  "key1":"Text for key 1",
  "key2":"Text for key 2",
  "nestedObjects":{
    "are":{
      "supported":"Use the key 'nestedObjects.are.supported' to refer to this resource"
    }
  }
}

Resource value format

Resource values are in ICU MessageFormat. This format supports constructing text at runtime based on parameters passed in from your code, and selecting alternative forms to handle things like pluralization and gender.

Named parameters

{
  "sayHello":"Hello {name}"
}

Plural forms

{
  "itemCount":"{count, plural, =0 {You have zero items} =1 {You have one item} other {You have # items}}"
}

Gendered forms

{
  "pronounSelection":"{gender, select, female {She did it!} male {He did it!} other {It did it!}"
}

Variations

It's important for Alexa skills to vary the words they use in response to users, lest they sound robotic. The Jargon SDK makes ths simple with built-in variation support. Variations are defined using nested objects:

{
  "resourceWithVariations":{
    "v1":"First variation",
    "v2":"Second variation",
    "v3":"Third variation"
  }
}

When rendering the key resourceWithVariations the Jargon SDK will choose a variation at random (with other more complex methods coming in future versions). If you render the same resource multiple times within a single request (e.g., for spoken content and for card or screen content) the SDK will by default consistently choose the same variation.

Note that you can always select a specific variation using its fully-qualified key (e.g., resourceWithVariations.v1)

You can determine which variation the SDK chose via the ResourceManager's selectedVariation(s) routines.

Runtime interface

RenderItem

A RenderItem specifies a resource key, optional parameters, and options to control details of the rendering (which are themselves optional).

interface RenderItem {
  /** The resource key to render */
  key: string
  /** Params to use during rendering (optional) */
  params?: RenderParams
  /** Render options (optional) */
  options?: RenderOptions
}

RenderParams are a map from parameter name to a string, number, or RenderItem instance.

interface RenderParams {
  [param: string]: string | number | RenderItem
}

The use of a RenderItem instance as a parameter value makes it easy to compose multiple resource together at runtime. This is useful when a parameter value varies across locales, or when you want the SDK to select across multiple variations for a parameter value, and reduces the need to chain together multiple calls into the ResourceManager.

The ri helper function simplifies constructing a RenderItem:

function ri (key: string, params?: RenderParams, options?: RenderOptions): RenderItem

handlerInput.jrb.speak(ri('sayHello', { 'name': 'World' }))

RenderOptions allows fine-grained control of rendering behavior for a specific call, overriding the configuration set at the ResourceManager level.

interface RenderOptions {
  /** When true, forces the use of a new random value for selecting variations,
   * overriding consistentRandom
   */
  readonly forceNewRandom?: boolean
}

JargonDialogflowApp and JargonActionsSdkApp

• Use the version that corresponds with the API your action is written against
• Installs middleware to create the Jargon per-request objects
• That middleware adds the following to the conversation object passed to your intent handlers

// Jargon extensions to the base Actions on Google Conversation
export interface Conversation<TUserStorage> {
  jargonResourceManager: ResourceManager
  jrm: ResourceManager

  jargonResponseFactory: ResponseFactory
  jrf: ResponseFactory
}

Intializing the Jargon SDK is simple:

const { JargonDialogflowApp } = require('@jargon/actions-on-google')

// Standard dialogflow app instantiation
const app = dialogflow()

// Install the Jargon SDK onto the application
new JargonDialogflowApp().installOnto(app)

ResponseFactory

• Simplifies the creation of response objects
• Each response type (simple, basic card, etc.) has a corresponding method that takes a Jargon variant of the options
  • The main difference with the Jargon variants is replacing user-visisble string fields with RenderItems

export interface JBasicCardOptions {
  title?: RenderItem
  subtitle?: RenderItem
  text?: RenderItem
  image?: GoogleActionsV2UiElementsImage
  buttons?: GoogleActionsV2UiElementsButton | GoogleActionsV2UiElementsButton[]
  display?: GoogleActionsV2UiElementsBasicCardImageDisplayOptions
}

export interface JSimpleResponseOptions {
  speech: RenderItem
  text?: RenderItem
}

export interface ResponseFactory {
  basicCard (options: JBasicCardOptions): Promise<BasicCard>
  simple (options: JSimpleResponseOptions | RenderItem): Promise<SimpleResponse>
}

ResourceManager

Internally ResponseFactory uses a ResourceManager to render strings and objects. You can directly access the resource manager if desired, for use cases such as:

• obtaining locale-specific values that are used as parameters for later rendering operations
• incrementally or conditionally constructing complex content
• response directives that internally have locale-specific content (such as an upsell directive)
• batch rendering of multiple resources
• determining which variation the ResourceManager chose

export interface ResourceManager {
  /** Renders a string in the current locale
   * @param {RenderItem} item The item to render
   * @returns {Promise<string>} A promise to the rendered string
   */
  render (item: RenderItem): Promise<string>

  /** Renders multiple item
   * @param {RenderItem[]} items The items to render
   * @returns {Promise<string[]} A promise to the rendered strings
   */
  renderBatch (items: RenderItem[]): Promise<string[]>

  /** Renders an object in the current locale. This also supports returning
   * strings, numbers, or booleans
   * @param {RenderItem} item The item to render
   * @returns {Promise<T>} A promise to the rendered object
   */
  renderObject<T> (item: RenderItem): Promise<T>

  /** Retrieves information about the selected variant for a rendered item. This
   * will only return a result when rendering the item required a variation
   * selection. If item has been used for multiple calls to a render routine
   * the result of the first operation will be returned; use selectedVariations
   * to see all results.
   * @param {RenderItem} item The item to retrieve the selected variant for
   * @return {Promise<SelectedVariation>} A promise to the selected variation
   */
  selectedVariation (item: RenderItem): Promise<SelectedVariation>

  /** Retrieves information about all selected variations for rendered item. This
   * will only return a result for items that required a variation selection
   * during rendering. Results are ordered by the ordering of the calls to render
   * routines.
   * @return {Promise<SelectedVariation[]>} A promise to the selected variations
   */
  selectedVariations (): Promise<SelectedVariation[]>

  /** The locale the resource manager uses */
  readonly locale: string
}

Note that the render routines return Promises to the rendered content, not the content directly.

ResourceManager is part of the package @jargon/sdk-core, and can be used directly from code that isn't based on the Actions on Google support library.

Adding to an existing action

Installation

Externalize resources