Device

The Jovo $device class allows you to retrieve device-specific features and capabilities.

Many Jovo apps work across different devices. Some devices might offer only audio output, others come with a screen. Some devices may even have specific information like an address.

The Jovo $device class groups everything you need to know about a device together. You can access it like like this:

this.$device;

The most relevant features of $device are capabilities and platform-specific features.

You can access a device's capabilities like this:

this.$device.capabilities;

// Example result: [ 'SCREEN', 'AUDIO' ] or [Capability.Screen, Capability.Audio]

You can also use the supports method to check if the device supports specific capabilities. It expects the Capability enum or the string value.

import { Capability } from '@jovotech/framework';

this.$device.supports(capability: Capability)

// Example for one capability
if (this.$device.supports(Capability.Screen)) {}
// or
if (this.$device.supports('SCREEN')) {}

// Example for multiple capabilities
if (this.$device.supports(Capability.Screen) && this.$device.supports(Capability.Video)) {}
// or
if (this.$device.supports('SCREEN') && this.$device.supports('VIDEO')) {}

The following capabilities are currently available in the generic $device class:

• AUDIO or Capability.Audio: It's possible to play audio output via SSML.
• LONGFORM_AUDIO or Capability.LongformAudio: It's possible to play long-form audio output, e.g. Alexa AudioPlayer or Google Assistant Media Response.
• SCREEN or Capability.Screen: It's possible to show visual output on a screen.
• VIDEO or Capability.Video: It's possible to play a video on a screen.

Some platforms like Alexa offer specific capabilities like APL. You can access them by prepending the platform name like this:

import { AlexaCapability } from '@jovotech/platform-alexa';
import { GoogleAssistantCapability } from '@jovotech/platform-googleassistant';

this.$device.supports(AlexaCapability.Apl);
// or
this.$device.supports('ALEXA:APL');

this.$device.supports(GoogleAssistantCapability.InteractiveCanvas);
// or
this.$device.supports('GOOGLE_ASSISTANT:INTERACTIVE_CANVAS');

If a platform offers specific device features beyond capabilities, you can access its $device object as part of the platform object. Here is an example for Amazon Alexa:

this.$alexa.$device;

The JovoDevice class is abstract and has to be implemented by every platform with a few generic and a couple of specific functions. The platform fills the capabilities array on initiation by calling the getDeviceCapabilities()-method of the platform-specific request-class.