addEventListener (callback)

Syntax

import messageHandler from '@vcita/intandem-app-com';

// ...initialize the handler

messageHandler.addEventListener((message, ack) => { ... });

Parameters

1. message MessageType:
   The incoming message type.

   Available message types

   Type	Payload	Description
   ChangeView	team|staff	Send the state of the view for either team or staff

   
   

2. callback Function:

   1. result String | Object :
   2. ack (Function):
      A function to acknowledge receipt of the message. Can optionally include:
      • Success or failure status (boolean).
      • Additional data, such as status messages or payloads (Object | String).

Usage

Here’s how to add a listener and use the ack function:

Example: Basic Success Acknowledgment

messageHandler.addEventListener(message:MessageType, (message, ack) => {
  console.log('Message received', message);
  ack(); // Acknowledge success with no additional data
});

Example: Success with Additional Information

messageHandler.addEventListener(message:MessageType, (message, ack) => {
  console.log('Processing message:', message);
  ack(true, '3 records added'); // Acknowledge success with a status message
});

Example: Success with Payload

messageHandler.addEventListener(message:MessageType, (message, ack) => {
  ack(true, { Uid: 123 }); // Acknowledge success with additional payload
});

Example: Failure with Error Message

messageHandler.addEventListener(message:MessageType (message, ack) => {
  ack(false, 'Unauthorized'); // Acknowledge failure with a reason
});

Example: Failure with Detailed Error Object

messageHandler.addEventListener(message:MessageType (message, ack) => {
  ack(false, { errorCode: 404 }); // Acknowledge failure with an error object
});

ack Function

Signature:

ack(status?: boolean, data?: string | object);

Parameters:

1. status (Optional, boolean):

   • true: Indicates success.
   • false: Indicates failure.

2. data (Optional, string | object | number):
   Additional data to provide context for the acknowledgment. Could be a string message or an object containing more detailed information.

Notes

• If ack is not called, the message will not be acknowledged, which may cause retries or other behavior depending on the implementation.
• Use meaningful messages or payloads in the acknowledgment to help downstream systems handle the response effectively.