removing a div with greasemonkey

Recently the news site nu.nl decided to give users with adblockers in place a slight slap on the wrist by adding a banner on top of each page with a message urging them to turn off the adblocker for their site. Because I really don't like ads, but also don't like big banners on top of each page, I decided to block the banner.

Greasemonkey looked like the right tool for the job. It is an add-on for Firefox that allows a user to add custom behaviour to pages by creating scripts that run on page load and can modify the html, css or javascript on a page. For Chrome Tampermonkey will do the same. To get Greasemonkey running, get it here and restart your browser. You will now see a little monkey head in the top right corner of your browser. You can install the script by opening this link to the script in your browser. Alternatively you can click on the arrow next to the monkey and choose "New user script...". Fill out the required fields and then paste the script below in the edit window (by default pasting is disabled in the editor so you may have to enable this first).
// ==UserScript==
// @name        nu-div-remover
// @namespace   janjongerden.nl
// @description Removes the div that complains about adblockers
// @include     http://www.nu.nl/*
// @version     1
// @grant       none
// @noframes
// ==/UserScript==

document.getElementsByClassName('adblocker')[0].remove()
The script is run on page load, for all urls starting with www.nu.nl and will remove the offending div from the DOM. In this case the div cannot be targeted by id, so instead the first div with class matching 'adblocker' is removed. Of the Greasemonkey annotations in the header the most interesting part is the @include, which states on which pages the script should run. The @noframes annotation prevents the script from running on each iframe within the page, making sure the script only runs once per url.

the mobile story

The story for mobile is a bit trickier: the Greasemonkey add-on is not yet available for Firefox on Android as far as I can tell. However, there is an alternative add-on, the Unified Script Injector. Even though the add-on claims to have only limited support for Greasemonkey scripts, it did the job for this simple script. Once you have installed the add-on, you can add new user scripts by opening a url to such a script when the url ends with "user.js". To install the div-remover script you can click here and the script will be installed. For me this does the job, although the removing of the div is a bit slower than in the desktop version, meaning I still see the banner for a second or so.