Detect “Do Not Track” with JavaScript
Do Not Track is an excellent idea. The DNT website describes it best:
Do Not Track is a technology and policy proposal that enables users to opt out of tracking by websites they do not visit, including analytics services, advertising networks, and social platforms. At present few of these third parties offer a reliable tracking opt out, and tools for blocking them are neither user-friendly nor comprehensive. Much like the popular Do Not Call registry, Do Not Track provides users with a single, simple, persistent choice to opt out of third-party web tracking.
The preference is sent from the client to the server via a HTTP header but you can also get its value using JavaScript:
// "1" or "unspecified"
if(navigator.doNotTrack == 1) {
// Do (or don't do) stuff.
}
If you wanted to be extreme about honoring your user's preference, you could use that to lazyload (or not) advertising, analytics, or other utilities. Probably a bit extreme but it's there for you to use!
![Camera and Video Control with HTML5]()
Client-side APIs on mobile and desktop devices are quickly providing the same APIs. Of course our mobile devices got access to some of these APIs first, but those APIs are slowly making their way to the desktop. One of those APIs is the getUserMedia API...
![7 Essential JavaScript Functions]()
I remember the early days of JavaScript where you needed a simple function for just about everything because the browser vendors implemented features differently, and not just edge features, basic features, like addEventListener and attachEvent. Times have changed but there are still a few functions each developer should...
![Select Dropdowns, MooTools, and CSS Print]()
I know I've harped on this over and over again but it's important to enhance pages for print. You can do some things using simple CSS but today's post features MooTools and jQuery. We'll be taking the options of a SELECT element and generating...
![Introducing MooTools LinkAlert]()
One of my favorite Firefox plugins is called LinkAlert. LinkAlert shows the user an icon when they hover over a special link, like a link to a Microsoft Word DOC or a PDF file. I love that warning because I hate the surprise...
Is the resulting value always a string or an integer except when unspecified (then it is a string), and are the values you stated the same cross-browser (especially the unspecified value)?
I really like how medium handles DNT.