WindowEventHandlers.onhashchange

The WindowEventHandlers.onhashchange property of the WindowEventHandlers mixin is the event handler for processing hashchange events.

The hashchange event fires when a window's hash changes (see Window.location and HTMLAnchorElement.hash).

Syntax

Using an event handler:

window.onhashchange = funcRef;

Using an HTML event handler:

<body onhashchange="funcRef();">

Using an event listener:

To add an event listener, use addEventListener():

window.addEventListener("hashchange", funcRef, false);

Parameters

funcRef

A reference to a function.

Examples

Using an event handler

This example uses an event handler (window.onhashchange) to check the new hash value whenever it changes. If it equals #cool-feature, the script logs a message to the console. 

function locationHashChanged() {
  if (location.hash === '#cool-feature') {
    console.log("You're visiting a cool feature!");
  }
}

window.onhashchange = locationHashChanged;

Using an event listener

This example uses an event listener to log a notification whenever the hash has changed. 

function hashHandler() {
  console.log('The hash has changed!');
}

window.addEventListener('hashchange', hashHandler, false);

Overriding the hash

This function sets a new hash dynamically, setting it randomly to one of two values.

function changeHash() {
  location.hash = (Math.random() > 0.5) ? 'location1' : 'location2';
}

The hashchange event

The dispatched hashchange event has the following properties:

Field Type Description
newURL DOMString The new URL to which the window is navigating.
oldURL DOMString The previous URL from which the window was navigated.

Polyfill for event.newURL and event.oldURL

// Let this snippet run before your hashchange event binding code
if (!window.HashChangeEvent)(function(){
  var lastURL = document.URL;
  window.addEventListener("hashchange", function(event){
    Object.defineProperty(event, "oldURL", {enumerable:true,configurable:true,value:lastURL});
    Object.defineProperty(event, "newURL", {enumerable:true,configurable:true,value:document.URL});
    lastURL = document.URL;
  });
}());

Specifications

Specification
HTML Standard
# handler-window-onhashchange

Browser compatibility

BCD tables only load in the browser

See also