Inline script tag filtering
Also see: remove-node-text
Back to Static filter syntax.
Script tag filters do not work in all browsers, due to browser API limitations:
- Not supported in Chromium-based browser.
- Starring the related Chromium issue may help motivate Chromium devs to implement support.
- Falling back on wholesale blocking of all inline script tags may work.[1]
- Not supported in Firefox's WebExtensions version of uBO when...
- Firefox 56 and less is used;
- uBO version 1.14.23b2 and less used.
[1] Through the use of the inline-script static filter option (||example.com^$inline-script), or through the use of a dynamic filtering block rule for inline scripts.
There are many ways to block script tags from executing in uBlock Origin:
- Block external script resources: these are taken care by network filtering.
- Block all inline script tags embedded in a page at once.[1]
Inline script tags are those blocks of JavaScript code which are embedded in the main page: they can not be blocked from downloading unless the whole page itself is blocked, which is not very useful. Here is a example of a web page's HTML code with two inline script tags:
<html>
<head>
<meta name="referrer" content="origin">
<link rel="stylesheet" href="main.css" />
<script type="text/javascript">
function usefulCode() {
...
}
...
</script>
<title>lorem ipsum</title>
</head>
<body>
<h1>lorem ipsum</h1>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.</p>
<script type="text/javascript">
function nuisanceCode() {
...
}
...
</script>
</body>In this example, blocking inline script tags wholesale would not be a good solution because both script tags would be blocked and we would lose the usefulCode function as well.
uBlock Origin 1.15.0 introduces HTML filtering, which can be used to remove specific inline script tags from a web page before the browser parses the HTML response from the server:
example.com##^script:has-text(...)
Where the value inside the parenthesis in has-text(...) can be a plain string or a literal JavaScript regular expression (/.../).
So we can use HTML filtering for our above example to specifically remove one of the script tags (assuming the page's URL is https://foo.example/bar.html):
foo.example##^script:has-text(nuisanceCode)
This filter means: for any web pages from the foo.example web site, remove all inline script tags which contains the string nuisanceCode.
In the cat and mouse game between web sites and blockers, the new script tag filter is a welcomed new tool on the user side, to foil attempt by site to work around blockers.
The big advantage of this new filter is that it can fix at the source many of the anti-blocker workarounds used by some web sites.
For example, the web site at http://focus.de/ will resort to deface itself with ridiculous ads when the site detects that the user is using a blocker, and using EasyList + EasyList Germany does not work, as the images pulled by the page are randomly named, defeating pattern-based network filters and cosmetic filters as well.
Wholesale blocking of inline script tags does prevent the self-defacing, but possibly at the cost of disabling other possible useful functionalities on the page. However, a script tag filter to block the specific inline script tag which contains the self-defacement JavaScript code allows a more targeted approach: prevent the undesirable inline JavaScript code from executing while keeping the desirable inline JavaScript code intact. At time of writing, this script tag filter worked for the site:
www.focus.de##^script:has-text(uabInject)
A concrete example of a site which resorts to self-defacement when it detects that a blocker is in use -- the front page of rp-online.de:
Without inline script tag filtering:
With an appropriate inline script tag filter:
The uBlock filters list, which is selected by default, already contains a couple of inline script tag filters to take care of some of these annoyances.