Return URL with JavaScript that Prevents Loading of Cached Pages

If you want to force a page to reload from the server rather than getting a cached copy, one way to do it is to append a query string to the URL.

If you want your web application to generate URLs that have this functionality, the code below can be implemented using JavaScript. Inside a file called BrowserUtility.js, insert this code.

function BrowserUtility()
{
	this.addNoCacheTimestamp =
		function(sUrl)
		{
			var ts = 'noCacheTS=' + (new Date()).getTime();
			sUrl = sUrl.trim();
			var nQIndex = sUrl.indexOf('?');
			sUrl+=(nQIndex==-1)?'?':(nQIndex===sUrl.length-1)?'':'&';
			return sUrl+=ts;
		};
};

var browserUtility = new BrowserUtility();

Once this is loaded, the function can be called like this, where the variable sUrl stores a URL:

sUrl = browserUtility.addNoCacheTimestamp(sUrl);

If the variable sUrl initially contained “http://example.com”, the returned string would be something like “http://example.com?noCacheTS=201808081203”.

Another option, if you did not want to use the current time as the query string value, would be to use a random number function instead.

(This is a snippet of code that I didn’t write – it was authored by my friend and colleague Jeff Konicky.)