Register Yourself

Register Yourself

Your document export engine ships in a core app, and the formats it can export ship in add-on apps — apps your core has never been compiled against and must never reference. This is the Discovery Event pattern from the BC design catalog: instead of the core keeping a list of providers, it asks "who is out there?" by publishing an event, and every provider that is listening writes itself into the answer. Your job is to build the core engine, the registration buffer it hands around, and one sample provider that plugs in from the outside.

Requirements

1. The registration buffer

Create a table named "Export Format Registration" with TableType = Temporary — registrations are collected in memory per discovery run and must never leave a row in the database.

• Field Code, type Code[20], and field Description, type Text[100]. Discovery results iterate sorted ascending by Code, regardless of the order providers registered in.
• A table procedure providers call to add themselves: procedure RegisterFormat(FormatCode: Code[20]; FormatDescription: Text[100]).
• Duplicate-code rejection: if the code is already registered, the call does nothing — the first registration wins, and a duplicate must never raise an error (one clumsy provider must not be able to kill everyone's discovery run).

2. The core engine

Complete the codeunit named "Export Format Engine". The starter already declares the two integration events it publishes — the grading tests subscribe to them, so keep their names, parameter names, types, order and var-ness exactly as declared; nothing raises them yet, and raising each one at the right moment is your job:

OnDiscoverFormats(var ExportFormatRegistration: Record "Export Format Registration")
OnExport(FormatCode: Code[20]; Payload: Text; var Output: Text)