Browser back/Forward button with saved warning message about page.js HOT 2 OPEN

IS there any update ?

from page.js.

What you are trying to do is not as simple as it seems. The browser's back button is a browser-level control, and, to the best of my knowledge, no major browser allows you to cancel or intercept the effects of the back button.
I have a similar requirement (although with a slightly wider scope) for a SPA that I'm working on, and it takes quite a bit of programming gymnastics to get it right — almost to the point of spaghetti code — since you're wrestling against the aforementioned limitations of the browser.
If you're only concerned about the back button, you could probably try replacing the current history state, then pushing a new one. That way, when the user moves backwards in the history, you'd be in a position to test for the first state. Something like this:

// --snip--
// the user changed the form
let state = history.state;
state.marked = true;
history.replaceState(state);

// --snip--
// define newState
history.pushState(newState, null);

// --snip--
// user presses the back button

// --snip--
// we are now in the middleware/route handler
if (history.state.marked) {
    let r = confirm("You pressed a Back button! Are you sure?!");
    if (r) {
        let state = history.state;
        delete state.marked;
        history.replaceState(state);
        history.back();
    } else {
        history.forward();
    }
}

Now, of course, the code above is just a very rough estimation of the algorithm. You'd have to do your own research and figure out how best to adapt this approach to your project. But, all in all, I don't think the issue that you've described is inherently related to page.js.

from page.js.