Inject attributes to an element while scrubbing

[vivekjMSFT]

is there a way that while scrubbing, the sanitizer can inject any attribute to an element. Such as while scrubbing anchor tags , I want to add target="_blank" to every anchor tag encountered by sanitizer?

[tiesont]

There isn't anything built in, but you could probably do that by subscribing to the PostProcessNode event, and adding that logic.

Since HtmlSanitizer uses the AngleSharp library for parsing HTML, you could also just use it directly on the sanitized markup.

[mganss]

Here's how you could do this using the PostProcessNode event:

sanitizer.PostProcessNode += (s, e) => (e.Node as IHtmlAnchorElement)?.SetAttribute("target", "_blank");

[richardtallent]

Perfect! This fixes my use case as well -- securing <a> tags with rel="noreferrer noopener nofollow".

[hammond13]

Nice example. I would think that adding "nofollow" to anchor tags would be a very common use case. I suggest adding that as an example in the wiki.

[mganss]

@hammond13 🆗, I've added example 5 to the wiki.

[vanillajonathan]

To anyone who stumbled across this, other rels which may be of interest include sponsored and ucg (user-generated content) according to Google.
https://developers.google.com/search/docs/advanced/guidelines/qualify-outbound-links

As well as external.
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/rel