Project: /docs/reference/js/_project.yaml Book: /docs/reference/_book.yaml page_type: reference

{% comment %} DO NOT EDIT THIS FILE! This is generated by the JS SDK team, and any local changes will be overwritten. Changes should be made in the source code at https://github.com/firebase/firebase-js-sdk {% endcomment %}

DocumentSnapshot class

A DocumentSnapshot contains data read from a document in your Firestore database. The data can be extracted with .data() or .get(<field>) to get a specific field.

For a DocumentSnapshot that points to a non-existing document, any data access will return 'undefined'. You can use the exists() method to explicitly verify a document's existence.

Signature:

typescript

export declare class DocumentSnapshot<AppModelType = DocumentData, DbModelType extends DocumentData = DocumentData>

Constructors

Constructor	Modifiers	Description
(constructor)()		Constructs a new instance of the <code>DocumentSnapshot</code> class

Properties

Property	Type	Description
id	string	Property of the <code>DocumentSnapshot</code> that provides the document's ID.
metadata	SnapshotMetadata	Metadata about the <code>DocumentSnapshot</code>, including information about its source and local modifications.
ref	DocumentReference<!-- --><AppModelType, DbModelType>	The <code>DocumentReference</code> for the document included in the <code>DocumentSnapshot</code>.

Methods

Method	Modifiers	Description
data(options)		Retrieves all fields in the document as an <code>Object</code>. Returns <code>undefined</code> if the document doesn't exist.<!-- -->By default, <code>serverTimestamp()</code> values that have not yet been set to their final value will be returned as <code>null</code>. You can override this by passing an options object.
exists()		Returns whether or not the data exists. True if the document exists.
get(fieldPath, options)		Retrieves the field specified by <code>fieldPath</code>. Returns <code>undefined</code> if the document or field doesn't exist.<!-- -->By default, a <code>serverTimestamp()</code> that has not yet been set to its final value will be returned as <code>null</code>. You can override this by passing an options object.
toJSON()		Returns a JSON-serializable representation of this <code>DocumentSnapshot</code> instance.

DocumentSnapshot.(constructor)

Constructs a new instance of the DocumentSnapshot class

Signature:

typescript

protected constructor();

DocumentSnapshot.id

Property of the DocumentSnapshot that provides the document's ID.

Signature:

typescript

get id(): string;

DocumentSnapshot.metadata

Metadata about the DocumentSnapshot, including information about its source and local modifications.

Signature:

typescript

readonly metadata: SnapshotMetadata;

DocumentSnapshot.ref

The DocumentReference for the document included in the DocumentSnapshot.

Signature:

typescript

get ref(): DocumentReference<AppModelType, DbModelType>;

DocumentSnapshot.data()

Retrieves all fields in the document as an Object. Returns undefined if the document doesn't exist.

By default, serverTimestamp() values that have not yet been set to their final value will be returned as null. You can override this by passing an options object.

Signature:

typescript

data(options?: SnapshotOptions): AppModelType | undefined;

Parameters

Parameter	Type	Description
options	SnapshotOptions	An options object to configure how data is retrieved from the snapshot (for example the desired behavior for server timestamps that have not yet been set to their final value).

Returns:

AppModelType | undefined

An Object containing all fields in the document or undefined if the document doesn't exist.

DocumentSnapshot.exists()

Returns whether or not the data exists. True if the document exists.

Signature:

typescript

exists(): this is QueryDocumentSnapshot<AppModelType, DbModelType>;

Returns:

this is QueryDocumentSnapshot<AppModelType, DbModelType>

DocumentSnapshot.get()

Retrieves the field specified by fieldPath. Returns undefined if the document or field doesn't exist.

By default, a serverTimestamp() that has not yet been set to its final value will be returned as null. You can override this by passing an options object.

Signature:

typescript

get(fieldPath: string | FieldPath, options?: SnapshotOptions): any;

Parameters

Parameter	Type	Description
fieldPath	string \| FieldPath	The path (for example 'foo' or 'foo.bar') to a specific field.
options	SnapshotOptions	An options object to configure how the field is retrieved from the snapshot (for example the desired behavior for server timestamps that have not yet been set to their final value).

Returns:

any

The data at the specified field location or undefined if no such field exists in the document.

DocumentSnapshot.toJSON()

Returns a JSON-serializable representation of this DocumentSnapshot instance.

Signature:

typescript

toJSON(): object;

Returns:

object

a JSON representation of this object. Throws a FirestoreError if this DocumentSnapshot has pending writes.