TreeObjectNode TypeAlias

A TreeNode which models a JavaScript object.

Signature

export type TreeObjectNode<T extends RestrictiveStringRecord<ImplicitFieldSchema>, TypeName extends string = string> = TreeNode & ObjectFromSchemaRecord<T> & WithType<TypeName, NodeKind.Object, T>;

Type Parameters

Parameter	Constraint	Default	Description
T	RestrictiveStringRecord<ImplicitFieldSchema>
TypeName	string	string

Remarks

Object nodes consist of a type which specifies which TreeNodeSchema they use (see schema(node) and object(name, fields)), and a collections of fields, each with a distinct key and its own FieldSchema defining what can be placed under that key.

All fields on an object node are exposed as own properties with string keys. Non-empty fields are enumerable and empty optional fields are non-enumerable own properties with the value undefined. No other own own or enumerable properties are included on object nodes unless the user of the node manually adds custom session only state. This allows a majority of general purpose JavaScript object processing operations (like for...in, Reflect.ownKeys() and Object.entries()) to enumerate all the children.

Field Assignment and Deletion Assigning to a field updates the tree value as long as it is still valid based on the schema. - For required fields, assigning undefined is invalid, and will throw. - For optional fields, assigning undefined removes the field's contents, and marks it as empty (non-enumerable and value set to undefined).

Example:

const Foo = schemaFactory.object("Foo", {bar: schemaFactory.optional(schemaFactory.number)});
const node = new Foo({bar: 1})

// This clears the field, is non-enumerable, and value is undefined.
delete node.bar;

// This is equivalent to the delete example.
node.bar = undefined

The API for fields is defined by ObjectFromSchemaRecord.