How to ignore popstate initial load, working with pjax

Question

I have been trying to get the forward an back browser buttons to work on a small site using pjax and have come up with the following code to handle class changes and fading in and out the various overlays.

However I have found that Chrome and Safari treats the initial page load as a popstate and so it is causing me grief. Is there anyway to stop this?

$(window).on("popstate", function() {
  if ($('body').hasClass('info')) {
    $('body').removeClass("info").addClass("work");
    $('.info_overlay').fadeOut(duration);
    alert('popstate');

  } else if ($('body').hasClass('work')) {
    $('body').removeClass("work").addClass("info");
    $('.info_overlay').fadeIn(duration);    

  } else {
    $('body').removeClass("project").addClass("work");
    $('.project_overlay').fadeOut(duration);
  }
});

Answer 1

Tag the state when you call pushState(), then ignore all popstate events that don't have your tag. e.g.

history.pushState({ myTag: true }, ...)

$(window).on("popstate", function(e) {
  if (!e.originalEvent.state.myTag) return; // not my problem
  // rest of your popstate handler goes here
}

Don't forget to call replaceState at page load so that you can handle the popstate when you get back to the initial page load.

$(function() { history.replaceState({ myTag: true }); });