object.md

Jovo Output Object

Learn more about the Jovo $output object.

• Introduction
• Output Structure
• platform.output Middleware

Introduction

The Jovo $output is a consolidated JSON object that prepared during routing , and later turned into a response in the platform.output Middleware.

You can access the object like this:

this.$output

If you log it after calling the tell method:

this.tell('Hello World!');
console.log(this.$output);

The logs for the $output object look like this:

{ 
  tell: { 
    speech: 'Hello World!' 
  } 
}

And the generated response would be the following:

// @platform=Alexa
{
	"version": "1.0",
	"response": {
		"shouldEndSession": true,
		"outputSpeech": {
			"type": "SSML",
			"ssml": "<speak>Hello World!</speak>"
		}
	},
	"sessionAttributes": {}
}

// @platform=Google Assistant
{
	"fulfillmentText": "Hello World!",
	"outputContexts": [
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/google_assistant_welcome"
		},
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/actions_capability_screen_output"
		},
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/actions_capability_audio_output"
		},
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/google_assistant_input_type_keyboard"
		},
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/actions_capability_web_browser"
		},
		{
			"name": "projects/<project-id>/agent/sessions/<session-id>/contexts/actions_capability_media_response_audio"
		}
	],
	"payload": {
		"google": {
			"expectUserResponse": false,
			"richResponse": {
				"items": [
					{
						"simpleResponse": {
							"ssml": "<speak>Hello World!</speak>"
						}
					}
				]
			},
			"userStorage": "{\"userId\":\"<user-id>\"}"
		}
	}
}

If you are reading the logs returned from the server (e.g. AWS CloudWatch), you can use the JSON.stringify() method to turn the object into a human-readable JSON string response:

this.tell('Hello World!');
console.log(JSON.stringify(this.$output, null, 4));

// Output:
{ 
    "tell": { 
        "speech": "Hello World!"
    } 
}

Output Structure

The $output object can contain elements for tell, ask, as well visual and plaform-specific output.

For example, it looks like this after ask:

{ 
  ask: { 
    speech: 'Hello World! What\'s your name?',
    reprompt: 'Please tell me your name.' 
  } 
}

platform.output Middleware

Learn more about the Jovo Framework Architecture here.

The platform.output middleware is used to turn the $output object into a $response object, as shown in the Introduction above.

The middleware turns the cross-platform output into platform-specific JSON responses based on the platform the framework is currently interacting with. This is why the $output object is helpful for Hooks and Plugins, as they then only need to worry about the abstracted object, not any possible response JSON structure.