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!
![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...
![fetch API]()
One of the worst kept secrets about AJAX on the web is that the underlying API for it, XMLHttpRequest, wasn't really made for what we've been using it for. We've done well to create elegant APIs around XHR but we know we can do better. Our effort to...
![Implementing Basic and Fancy Show/Hide in MooTools 1.2]()
One of the great parts of MooTools is that the library itself allows for maximum flexibility within its provided classes. You can see evidence of this in the "Class" class' implement method. Using the implement method, you can add your own methods to...
![Create Tiny URLs with TinyURL, MooTools, and PHP]()
Since we've already figured out how to create TinyURL URLs remotely using PHP, we may as well create a small AJAX-enabled tiny URL creator. Using MooTools to do so is almost too easy.
The XHTML (Form)
We need an input box where the user will enter...
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.