As of v2020.1.1 once connect to a cloud file source (Google Drive/Sheets, Box, Dropbox, or OneDrive) Tableau Prep will not refresh the file until the application is entirely closed and re-opened and then the flow re-opened (and we typically have to re-authenticate as well). If the flow just has connections to cloud file sources the Refresh button is completely greyed out. If the flow has a mix of cloud file sources and others (like local files) the Refresh button will appear but it doesn't actually trigger a refresh for the cloud file sources.
As far as I can tell what's happening is the following:
- When Prep connects to the cloud file it downloads the cloud file into a temp folder. I'm on macOS and for a Box file Prep is placing it into /private/tmp/prep-5054UzcTcmWeFuw3/tableau-temp/11hw38w0n684mk11yf5ur0tb1yk7/Prep + updated Box Excel file.xlsx. Everything up through the /tableau-temp/ is for the application instance, everything after that is for the particular Prep flow & connection.
- For as long as Prep is open all the cloud files files have local copies in the temp folder for that application instance and those persist so long as the application is running.
- Therefore if I close a flow while leaving Prep running (which is how macOS apps commonly behave) and then re-open the flow then it's still using that same temp folder, finds the local copy of the cloud file, and uses that. So we don't see any updates to the cloud file.
- If I completely exit Tableau Prep then the ..../tableau-temp/ folder is deleted.
- Then the next time I launch Tableau Prep it creates a new temp folder. When I open a flow with a cloud file I'm prompted to reconnect to the cloud file, and after I do so a fresh copy is downloaded into the temp folder.
So if I'm completely closing and opening Tableau Prep it'll refresh the data, but if I'm in a long session of flow editing then I can't refresh the cloud file source data. I'd thought something was a little odd, thanks to Nathan DeVries for pointing it out. This behavior is:
a) Not user-friendly. This is not how Tableau Prep works for local files or databases, and loses the advantage of cloud file sources for things like collaborative editing. Also on macOS if I'm editing multiple flows then I have to close *all* instances of Tableau Prep to get a refresh of just one connection in one flow.
b) Undocumented (as of 8 Feb 2020).
c) Also different from Tableau Desktop, which does enable refresh of cloud file sources just like other types of data sources.
Please enable refresh for cloud file sources.