Alejandro Duarte:
I’m not sure I understand what you mean, but if what you want is to update a Grid from a loop that takes time, you can use a background Thread and Push. See this video: https://www.youtube.com/watch?v=EG6iizVH1rY and [this part]
(https://vaadin.com/docs/v8/framework/advanced/advanced-push.html) of the documentation.
This works when you scroll the items than it will visible to the browser.
In my case i need to display latest created row in first position so i always need to place newly created item in first position. so in that case it doesn’t reflect to the browser instantly.