The foreign-key field itself, carrying RelatedEntityFilter / RelatedEntityOrderBy.
Fields the dropdown will read from each row: primary key, name, extra columns, icon.
The related entity's name field name.
From the field's [FKLookupOptions] input, plus ExtraFilter and OrderBy contributed by
[FKExtraFilter] / [FKOrderBy]. Opaque to the field; each strategy documents its own keys.
The related entity's primary key field name.
What the user has typed. Empty when the dropdown was opened by focus.
The record being edited — the host of the foreign key, not the record being looked up.
The field the user is searching — the name field unless they chose another column on the dropdown's scope pill. A typed query is matched against this column.
Everything a strategy needs to answer one lookup. Rebuilt per keystroke.