Ajax error after a committed create: retry duplicates in DataTables Editor

Answer first

No, DataTables Editor does not provide a built-in idempotency key or automatic rollback for a create that commits on the server but fails on the Ajax response path. An idempotency token must be added by application code, and the client-side reconciliation after a post-commit failure is a manual re-fetch/redraw, not an Editor state rollback.

Confirmed facts

• Editor does not generate idempotency keys. The submit payload is built from the form data and any custom data you supply.
• In Editor 1.10+ the submit flow is Promise based. In 1.9 it is callback based with a different error object shape. The two generations are not interchangeable for error handling.
• Editor has no built-in retry or duplicate suppression. If the Ajax layer reports a timeout, non-200, or malformed JSON after the server has already inserted the row, the client cannot know whether the row exists.

Likely explanation

"Never reached the server" and "response lost after commit" are indistinguishable from the browser. An automatic retry will therefore risk a duplicate insert, while no retry leaves the UI stale. The safe ownership model is server-side deduplication keyed by a client-generated token, with client-side reconciliation by re-reading server state.

Steps for this case

1. Confirm the Editor generation in use. The API for attaching data and handling errors differs between 1.9 and 1.10+. This changes the recommendation.
2. Generate a client token once per logical create, before submit. Keep it stable for any retry of that same user action.
3. Inject the token into the submit payload via application code. The common injection points are the submit option's message property or an onSubmit callback that merges custom data into the request before it is sent. Editor will then forward it with the normal Editor request.
4. On the server, treat the token as an idempotency key: return the existing row on a repeat submit instead of creating a new one.
5. On Ajax error, do not auto-retry silently. Either prompt for manual retry with the same token, or reconcile immediately by reloading server state: table.ajax.reload(null, false). Editor does not offer state rollback.

Practical verification

• Log the outgoing payload in onSubmit to verify the token is present.
• Use the Network tab to confirm a retry resends the same token and the server response is idempotent.
• After a simulated post-commit failure, run a reload and verify the table reflects server state without manual duplicate removal.

Assumption: you control both client and server. Uncertainty remains around the exact Editor version installed, which determines the correct hook name and error object shape. Providing the version will remove the remaining ambiguity about the precise submit hook to use.