Pressing Apply starts a change that runs in the background and lands on its own page, Changes to N rows. You can leave and come back; a banner on the grid says a change is running, with View progress.
While it runs
"Reading your store" with a bar, then the count of rows done, with three tallies, refreshed every two seconds. "Waiting for Shopify" shows while Shopify asks the app to slow down. It passes on its own.
Only what you changed is sent
A row is written in one go, with only the cells you changed. A cell you did not touch is never sent, so nothing else on the row can change.
Every value is read back
After a row is written, each value is read back from your store. A cell is Updated only when the value read back is the value you sent.
When it ends
The banner says how it went: "All 40 variants were updated", or that some could not be, or "Applying these changes stopped partway". Under it, every cell is listed with Before, Applied and its outcome:
- Updated, with the value read back.
- Unchanged: your store already held that value.
- Failed, with Shopify's reason, for example a price that cannot be blank or a value too long for its field.
- Not updated: the row was not reached. See A change that stopped partway.
A large result gets chips, Failed, Updated, Unchanged, All, and pages.
Afterwards
The page offers Revert these changes when at least one value was written. See Reverting a change. Home's Last applied links the latest result.