Handling Offline Message Responses in SUSI Web Chat

Previously, the SUSI Web Chat stopped working when there was no Internet connectivity. The application’s overall state was disturbed as one would see the loading message gif and the users were left to wonder on how to proceed. To handle this situation, we required notifying the User in the offline mode, with a message, that there is no Internet Connectivity.

This following image demonstrates the previous state where the application hung.

This image shows how this state was handled currently. One can test this out on http://chat.susi.ai by disconnecting and sending a message to SUSI and then connecting back to the Internet.

To achieve this, one needed to handle the offline and online events of the browser. The following steps can be followed to achieve this.

  1. We make use of the following eventListener functions to know whether the user is connected to the Internet.
// handles the Offlines event
window.addEventListener('offline', handleOffline.bind(this));  

// handles the Online event
window.addEventListener('online', handleOnline.bind(this));
  1. We then set a global offline message which is modified on the connections switching from online to an offline state. They are handled by the following functions.
let offlineMessage = null;

function handleOffline() {
  offlineMessage = 'Sorry, cannot answer that now. I have no net connectivity';
}
function handleOnline() {
  offlineMessage = null;
}
  1. We then handle the action createSUSIMessage() in API.actions.js and send the  AJAX request which we are making according to the offline/online state. This enables us to send the correct message response to the User even in the offline state and not letting the Application state crash.
// So if the offlineMessage variable is not null we call the AJAX 
if(!offlineMessage){
        // handle AJAX
}
else {
    // we create a message saying there is no Internet connectivity.
}
     
  1. The messages on refreshing back restore back to the original state as these are not being stored in the server. Hence the User is able to see the correct History, i.e., only those messages which were sent to the server and successfully responded to by SUSI.

Resources

Showing Offline and Online Status in SUSI Web Chat

A lot of times while chatting on SUSI Web Chat, one does not receive responses, this could either be due to no Internet connection or a down server.

For a better user experience, the user needs to be notified whether he is connected to the SUSI Chat. If one ever loses out on the Internet connection, SUSI Web Chat will notify you what’s the status through a snack bar.

Here are the steps to achieve the above:-

  1. The first step is to initialize the state of the Snackbar and the message.
this.state = {
snackopen: false,
snackMessage: 'It seems you are offline!'
}
  1. Next, we add eventListeners in the component which will bind to our browser’s window object. While this event can be added to any component in the App but we need it in the MessageSection particularly to show the snack bar.

The window object listens to any online offline activity of the browser.

  1. In the file MessageSection.react.js, inside the function componentDidMount()
  1. We initialize window listeners in our constructor section and bind them to the function handleOnline and handleOffline to set states to the opening of the SnackBar.
// handles the Offlines event
window.addEventListener('offline', this.handleOffline.bind(this));  

// handles the Online event
window.addEventListener('online', this.handleOnline.bind(this));
  1. We then create the handleOnline and handleOffline functions which sets our state to make the Snackbar open and close respectively.
// handles the Offlines event
window.addEventListener('offline', this.handleOffline.bind(this));  

// handles the Online event
window.addEventListener('online', this.handleOnline.bind(this));
  1. Next, we create a Snackbar component using the material-ui snackbar component.

The Snackbar is visible as soon as the the snackopen state is set to true with the message which is passed whether offline or online.

<Snackbar
       autoHideDuration={4000}
       open={this.state.snackopen}
       message={this.state.snackMessage}
 />

To get access to the full code, go to the repository https://github.com/fossasia/chat.susi.ai

Resources