Add option to footer component allowing ‘The following links open in a new tab’ guidance to be followed

[wimdavies]

Related component

Footer

Context

My team has received a request to have one of our services's footer links open in new tabs. We want to follow the guidance for this scenario:

If you’re displaying lots of links together and want to save space and avoid repetition, consider doing both of the following:

• adding a line of text before the links saying ‘The following links open in a new tab’
• including (opens in new tab) as part of the link text, so that part of the link text is visually hidden but still accessible to screen readers

However, there's no approved html example of implementing the ‘The following links open in a new tab’ text above the links. Moreover, there's no option providing this in the nunjucks macro, which is what our team relies on.

Issue #1782 noticed this absence back in 2020, but unfortunately nothing came of it; see also its sibling issue on govuk-design-system.

I also note that the ONS Design System has an implementation in place for this accessibility principle in their footer macro, an option they call "newTabWarning". Perhaps this could be a model for bringing this feature into GDS?

Alternatives

In the short term we will likely have to follow whatever html implementation the team that's asking us to make this change has made at their end. However for consistency across our services, it's desirable for us to be able to use the macro in all of them, due to how they share parent templates.