I have a backbone app where I want to open an overlay which is just a page with its own URL. You can also navigate in this overlay with different pages/URLs. So when the overlay is closed I want to set back the hash to the state before the overlay was opened. As the overlay is opened by a link I can't get the hash from the state before.

So is there a way to get the previous hash when a hash changed?

I have a backbone app where I want to open an overlay which is just a page with its own URL. You can also navigate in this overlay with different pages/URLs. So when the overlay is closed I want to set back the hash to the state before the overlay was opened. As the overlay is opened by a link I can't get the hash from the state before.

So is there a way to get the previous hash when a hash changed?

• javascript
• backbone.js
• browser-history

Share Improve this question Follow edited Jul 4, 2024 at 20:08 Jason Aller 3,6522828 gold badges4141 silver badges3939 bronze badges asked Jul 18, 2012 at 13:26 Andreas KöberleAndreas Köberle 111k5858 gold badges280280 silver badges307307 bronze badges

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3 Answers 3

Sorted by: Reset to default 3

The hashchange event has a "oldURL" field.... store all the "oldURL" (or only the last one) and, when you need it, change the actual url with the last url.

Source: https://developer.mozilla/en/DOM/window.onhashchange

I came up with this little hack. When the the overlay is opened I store the window.history.length. When the overlay is closed I call window.history.go with the difference between the stored length and the actual and subtract 1.

var appStateActions = {
  overlayPre: function(){
    this.historyPosition = window.history.length;
  },
  overlayExit: function(){
    window.history.go(this.historyPosition - window.history.length -1);
  }
}

Unfortunately this doesn't work cause of the limit of the history. So you get a wrong result after you reach the the limit of history length.

var historyurl =[];

$(window).on('hashchange', function(e){
    historyurl.push(location.hash); 
   if(historyurl.length > 2){ 
       historyurl.splice(0,historyurl.length-2)
     }; 
});

console.log("Last Hah Url ="+historyurl[0])