URLs using CiviCRM tokens in base templates are being rewritten by mosaico library code

[johntwyman]

We have some custom base templates that include the CiviCRM {action.unsubscribeUrl} and {action.optOutUrl} tokens:

<a href="{action.unsubscribeUrl}" target="_blank" style="text-decoration:none;color:#ffffff;"><span style="color:#ffffff;">Unsubscribe from this list</span></a>

When creating a new mailing from these base templates, we find that the URLs are being rewritten to:

<a href="http://cividev.localhost:7979/sites/default/files/civicrm/ext/customtmosaicotemplates/basetemplate/{action.unsubscrubeUrl}" ...

After some investigation, the cause of the problem lies in this function in the mosaico library. It's invoked by way of the code starting at this comment.

Because {action.unsubscribeUrl} does not meet any of the regex patterns, the URL is rewritten to include the base path of the extension.

I can't think of any reason why we could not include a regex along the lines of /^\{/?

[johntwyman]

Pinging @seamuslee001 as we've been discussing this already.