It is known that browsers are built to show a progress or waiting for the response of a URL when a URL is submitted to a server. Thus, if you take IE for example, we can see a rounded image moving which represents that it waits for a response. We do not have to code for that as browsers are built like that.

Desktop applications sometimes will include a browser container in their form. If we control the desktop application, it is easy to intercept the in and out events to act accordingly to achieve the same purpose. However, if you do not control the desktop application, thus the client is giving a URL to call one of your page on your server, and the client wishes to have the same representation, what kind of approach would you do?

Some will try to initiate a javascript code locally to start such representation before calling the URL. This is getting somewhat complicated when you have to support GET & POST for example. Also, you need to intercept that on the incoming. I have done that before but this was only for GET and for only one or two pages. My perception is that should be at the container level, thus in the client application. But, they do not want to negotiate thus from a link in such a page we return, we need to do all this job from the server end.