InteractiveCanvas (Dialogflow)

AI-generated Key Takeaways

• The interactiveCanvas object in your web app interfaces with your conversational action and is attached to the window object.

• The ready method must be called as soon as your web app loads to register callbacks and prevent the Action from closing.

• The sendTextQuery method allows you to send a text query to the conversational action with a maximum length of 640 characters.

• The getHeaderHeightPx method determines the height of the header at the top of the display in pixels.

• InteractiveCanvasCallbacks like onUpdate and onTtsMark allow your web app to respond to information or requests from the conversational action.

The interactiveCanvas object is the interface to your conversational action that is made available within your web app.

Note: The interactiveCanvas object is attached to the window object. If you are using a front-end framework to develop your web app, you need to ensure that you have access to window to set up the API.

Methods

ready

ready(callbacks) returns undefined

Called by the Interactive Canvas web app once it has loaded to register callbacks.

Parameters
callbacks	InteractiveCanvasCallbacks An object that contains method callbacks.

Note: You must invoke the ready API in the web app as soon as the page is loaded. Otherwise, the Action will close.

sendTextQuery

sendTextQuery(textQuery) returns Promise<state>

Sends a text query to the conversational action.

Parameters
textQuery	string The query to send to the conversational action.
state	string One of the following: READY: Requests can be accepted by the platform. BLOCKED: There is a query in flight and the new query will be dropped. UNKNOWN: The current query state couldn't be determined.

Caution: textQuery must be 640 characters or less.

getHeaderHeightPx

getHeaderHeightPx() returns Promise<height>

Determines the height of the header at the top of a display.

Parameters
height	number The height in pixels.

InteractiveCanvasCallbacks

These callbacks provide a way for you to respond to information or requests from your conversational action while the methods provide a way to send information or requests to your conversational action.

onUpdate

onUpdate(data) returns undefined

Called when an HtmlResponse is sent from the conversational action. After the end of the function call, the TTS will start immediately.

Parameters
data	Object Updated data sent by the webhook.

onTtsMark

onTtsMark(markName) returns undefined

Callback that is invoked during TTS playback.

Special marks that always are triggered:

• START indicates the start of the TTS.
• END indicates the end of the TTS.
• ERROR indicates an error playing the TTS.

You can also define custom marks by using SSML and the <mark> tag, like <mark name="custom"/>.

Note: SSML marks are not invoked when the following occurs:

• Before TTS begins, the user taps the microphone, or the Interactive Canvas client invokes sendTextQuery. The TTS is cancelled and any SSML marks in the TTS are ignored.
• During TTS, the user taps the microphone, or the Interactive Canvas client invokes sendTextQuery. The TTS is interrupted and any remaining SSML marks in the TTS are ignored.

Parameters
markName	string Mark name invoked during TTS playback.