How to detect/track postback in javascript?

Question

How to detect/track/check postback in javascript(e.g in asp.net Page.isPostBack())? Any suggestion?

Answer 1

If you want to check whether the current page will be a postback if the user clicks on a submit button, you can check for the presence of ViewState:

You can use something like document.getElementById("__VIEWSTATE") or the jQuery equivalent.

However, if you want to see whether the current page was generated in response to a postback, then you need to insert that data into the page on the server side first.

For example:

function isPostBack() {
  return <%= Page.IsPostBack %>;
}