ReactJS window.addEventListener("hashchange") not working

Question

I have a React component called Home. Within Home, I have a function "urlListener" in which I have added an event listener to alert whenever the URL is being changed.

var Home = React.createClass({
	getInitialState: function () {
		return {
			openedFile: this.props.location.query.file || '',
			apps: [],
			showNav: this.props.location.query.file ? false : true,
			layout: 'row',
			cloneAppName: 'New Application',
			appName: 'Application Name',
			showSave: false
		}
	},
	urlListener: function(){
		window.addEventListener("hashchange", function(){
                       saveUnsaved();
		});
	},
        saveUnsaved: function(){
        }

The listener works fine and is being called whenever there is a change in the URL. However, the console says that the function I'm trying to call is not a function. I am new to React and any help on this would be appreciated.

Answer 1

Someone had commented the answer which seemed to work for me, but the comment was removed before I could accept the answer. The correct way of doing it is

{() => this.saveUnsaved();}

The arrow function apparently switches the context from "window" to "this"(the current component) internally. Without the arrow function, "this" would be referring to the "window" component.