Push or replace history state for ncm.com

gistfile1.txt

// Function to "update" state by pushing or replacing depending on current state.
function updateState(queryParams) {
  //Build other options.
  var title = document.title;
  var newUrl = window.location.protocol + '//' + window.location.host + window.location.pathname + '?' + queryParams;
  // Do we already have a query state that we've pushed? Let's look at window.location.search to find out.
  if (window.location.search.length > 1) {
    // If so, let's replace it.
    window.history.replaceState({}, title, newUrl);
  } else {
    // If not, we'll make the history addition.
    window.history.pushState({}, title, newUrl);
  }
}


// When someone makes a change that changes the state (moves a piece, changes settings), we give the new serialized data to the function and execute.

// Query Params to append, gathered up however you may be doing so...

var queryParams = 'fen=rnbqkbnr%2Fpppppppp%2F8%2F8%2F8%2F8%2FPPPPPPPP%2FRNBQKBNR+w+Kq+-+0+1&flipped=false';

updateState(queryParams);