Here’s what i found about a year ago, when i started writing a document on using Airtable with Google Drive and Dropbox (a document I never completed, as it turns out):
Airtable allows one to prepend ‘file://’ to strings within a URL field. What is more, Airtable clearly understands this to be a file URL, as ‘file://C:[etc]’, ‘file://localhost/C:[etc]’, and ‘file:///C:[etc]’ are all normalized to link to ‘file:///C:[etc]’.
I then went on to say:
Now that one has converted the file path into a properly formatted file URL, selecting the link should open the file with a local app, right? Wrong. The security model underlying most modern browsers prohibit them from opening a file URL as a hyperlink from a non-local web page. That is to say, any ‘file://’ links defined on a page accessed as an ‘http://’ or ‘https://’ URL typically cannot be opened by selecting the link.
The solution? There are — or, at least, were — browser extensions that purposefully break the security model to allow one to load a ‘file://’ URL from a remote page. At the time, I provided links to Local Explorer for Chrome and Local Filesystem Links and LocalLink for Firefox. Are these still valid? I dunno. Keep in mind the security model exists for a reason, so you potentially open yourself up to evil. As I recall,
Local Filesystem Links incorporated a whitelist of sites where the add-on would be active; otherwise, the default security model held.
Again, it’s been a year since I played around with this, so your mileage may vary. Every piece to the puzzle is a moving part, and Airtable, browsers, and possibly the plugins are likely to have been modified multiple times since I wrote those words.
On the other hand, even if they don’t work correctly today, at least you know the general direction you need to look for answers…