Respect HTTP Cache-Control header when caching an Excel Add-in's JSON Metadata file
Currently, Excel will permanently cache an Add-in's custom functions JSON metadata file. This happens when the Add-in is first added to Excel.
The JSON metadata file may be updated from time to time for various reasons. It could be as trivial as correcting a typo in a custom function's description. It could be as serious as adding a new custom function altogether. Regardless, Excel currently doesn't fetch the new JSON file.
The only ways to get Excel to fetch the new JSON file appear to be:
(1) Submit a new XML manifest to AppSource with a new version number, even though the rest of the manifest are unchanged. This also contradicts the https://docs.microsoft.com/en-us/office/dev/store/appsource-submission-faq which says we don't have to resubmit if we make changes only to the web service.
(2) Ask users to manually reinsert the Add-in from Office Store.
(3) Ask users to manually clear the Office Cache.
All of the above seems unnecessarily complicated, when Excel could simply respect the HTTP Cache-Control headers returned by the server.
Incidentally, Excel already respects the HTTP Cache Control headers for other files, such as the custom functions HTML and JavaScript files. So I suggest we extend that same treatment to the custom functions JSON metadata file.
1 Comment
Definitely, a huge experience breaker for our clients too, and decreases confidence in the product, having to clear the office cache or force-push an essentially unchanged manifest.
