Instance Property インスタンスプロパティ

document

The current document model.

Declaration 宣言 

var document: Document { get nonmutating set }

Discussion 議論

Setting a new value marks the document as having changes for later saving and registers an undo action to restore the model to its previous value.

If isEditable is false, setting a new value won’t have an effect and the document is in viewing mode.