How to use a progressbar managed from the endpoint

In this video we will show how you can manage a progress bar from the endpoint.
If you have a processing endpoint that might take longer that 2 seconds, it is a good idea to visualize a progressbar on the frontend while this transaction is being executed.
This technology is handled via the websocket system.
You can use 2 types of progress bars. The step-by-step or the infinite. 
In both cases you have full control over the state/value and the texts that are being displayed.