Documentation doesn't explain how to identify links that should be decorated

[andyhd]

The Consent API client Javascript automatically decorates link URLs with the UID (if it exists). But it only decorates links which have a data-consent-share data attribute. This is not mentioned in the documentation and so implementors do not have all the information they need to integrate with the API.

[andyhd]

James King at DfE said that the content on https://find-employer-schemes.apprenticeships.education.gov.uk/ is managed by a CMS, and so adding data-attributes to the links is not straightforward.

An alternative method of identifying links to decorate would be easier in this case. Some options to consider:

• Decorate all links with absolute URLs. This would be simple, but would have some false positives and potentially cause issues
• Decorate links with URLs where the origin does not match the current document origin. This would reduce the number of false positives, but could still pass the URL parameter to sites not integrated with the Consent API. Is this an issue?
• Check whether the destination origin is known to the Consent API. This would add at least one additional HTTP request to every page view (with a cookie or URL parameter set). May require some significant changes to the API, including adding user registration/admin to provide lists of allowed origins. On the plus side, it would eliminate false positives.