Communicate from your screen app

Communication from your screen app is the most important factor to get a dynamic app that integrates with connected IoT apps. Because without communication you're left with a fancy website on dedicated hardware.

Send messages to another app

First, let's have a look at sending messages from a screen app to the device it is running on. These messages can be received in other apps on the same device.

To send a message, you need to use the usePublish hook from the @ombori/ga-messaging package. An example.

import { usePublish } from ‘@ombori/ga-messaging’;

const App = () => {
    const publish = usePublish();
    publish("event.name", {data: "data here"});
}

The entire payload will be sent.

Receiving Messages from a different app

When you want to receive messages sent by other apps (mainly IoT) on the same device, you need to use the useSubscribe hook from the @ombori/ga-messaging package. An example.

import { useSubscribe } from ‘@ombori/ga-messaging’;
const App = () => {
   useSubscribe('event.name', (data) => {
     // data contains payload
   }, [])
}

The data sent will be present in the data variable.

The hook useSubscribe is an extension to the built-in useEffect in React. To read more about the extendability and configuration of useEffect check the React Documentation

The Iot App's side

To learn how to send and receive messages from the IotT's end, check the Communicate with your IoT App documentation