Long running process, show progress in UI

Question

I want to trigger a long running background process (coded as a service) from the ui. But I also want to show some progress of that task to the user.

How can I achieve this? (I want to not infringe on decoupling). Is there a best practice to solve it (combining design-patterns, eg. observer and command)?

Answer 1

Here is an example on how to use just the observer pattern to show progress in the UI. With JAVA sample code provided:

Using Observer Pattern to track progress while loading a page