ExternalEditorConfig

ExternalEditorConfig interface

assume_formula	optional	boolean boolean	assume that we're editing a formula. does not require leading `=`. defaults to `true` for historical reasons.
dependencies		DependencyList DependencyList	list of dependencies to highlight. we support undefined entries in this list so you can use the result of `EmbeddedSpreadsheet.Resolve`, which may return undefined.
nodes		HTMLElement[] HTMLElement[]	a list of nodes that will serve as editors. when you attach, we will do an initial pass of context highlighting. we highlight on text changes and insert references if you make a selection in the spreadsheet while an editor is focused.
update		ExternalEditorCallback ExternalEditorCallback	this callback will be called when the selection changes in the spreadsheet and this external editor is active. return an updated list of dependencies to highlight. NOTE: this is currently synchronous, but don't rely on that. it might switch to async in the future depending on how it works in practice.