how to get feedback from server in the mid of server call

how to get feedback from server in the mid of server call

  

i have image orc app, 

it allows user to upload a image,

 the app send the image to server, 

server send it to google vision API, 

google API send back the result, 

server process the result, 

send the final output to phone.

This whole process takes a long time 20-30 seconds, while it process, the user have to wait, is it possible to send the result for each step back to the phone, show progress, user will feel more engaged, feel less slow? 

understand that it's not a good practice to call server multiple times, any other way around this? thanks.

Hi Linguo,

have you thought about using Firebase to implement push notifications?

You already have a component in OutSystems' Forge: http://www.outsystems.com/forge/1406/