Preview Without a Trace

Preview Without a Trace

Every accountant's favorite button is Preview Posting: show me exactly the ledger entries this journal would create — without creating them. The naive implementation posts for real and cleans up after itself, and it always leaves fingerprints: a burned entry number, a fresh SystemId, a commit that quietly made something permanent. The pattern behind Business Central's own posting preview rehearses the real posting and then makes the whole rehearsal vanish. You build that pattern on a custom ledger.

The starter ships four finished data objects. Do not rename them or their fields — the grading tests bind to every name below character for character.

The objects you get

• Table "Reward Journal Line" — primary key "Line No." (Integer); fields "Customer No." (Code[20]), Points (Integer), Description (Text[50]).
• Table "Reward Ledger Entry" — primary key "Entry No." (Integer); fields "Customer No." (Code[20]), Points (Integer), Description (Text[50]), "Register No." (Integer).
• Table "Reward Register" — primary key "No." (Integer); fields "From Entry No." (Integer), "To Entry No." (Integer).
• Table "Reward Setup" — primary key "Primary Key" (Code[10]); fields "Last Entry No." (Integer), "Last Register No." (Integer). The single row with a blank "Primary Key" always exists when your code is called — the tests seed it.

Requirements

Implement both procedures in the codeunit "Reward Posting":

procedure Post()
procedure Preview(var TempRewardLedgerEntry: Record "Reward Ledger Entry" temporary; var TempRewardRegister: Record "Reward Register" temporary)