Class DocumentSnapshot (5.0.2)

A DocumentSnapshot is an immutable representation for a document in a Firestore database. The data can be extracted with [data()] or [get(fieldPath)] 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] property to explicitly verify a document's existence.

DocumentSnapshot

Package

@google-cloud/firestore

Constructors

(constructor)(ref, _fieldsProto, readTime, createTime, updateTime)

constructor(ref: DocumentReference<T>, _fieldsProto?: ApiMapValue | undefined, readTime?: Timestamp, createTime?: Timestamp, updateTime?: Timestamp);

Constructs a new instance of the DocumentSnapshot class

Parameters

Name	Description
ref	`DocumentReference<T>` The reference to the document.
_fieldsProto	`ApiMapValue \| undefined` The fields of the Firestore `Document` Protobuf backing this document (or undefined if the document does not exist).
readTime	`Timestamp` The time when this snapshot was read (or undefined if the document exists only locally).
createTime	`Timestamp` The time when the document was created (or undefined if the document does not exist).
updateTime	`Timestamp` The time when the document was last updated (or undefined if the document does not exist).

Properties

_fieldsProto

readonly _fieldsProto?: ApiMapValue | undefined;

createTime

get createTime(): Timestamp | undefined;

The time the document was created. Undefined for documents that don't exist.

{Timestamp|undefined} DocumentSnapshot#createTime

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then(documentSnapshot => {
  if (documentSnapshot.exists) {
    let createTime = documentSnapshot.createTime;
    console.log(`Document created at '${createTime.toDate()}'`);
  }
});

exists

get exists(): boolean;

True if the document exists.

{boolean} DocumentSnapshot#exists

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then((documentSnapshot) => {
  if (documentSnapshot.exists) {
    console.log(`Data: ${JSON.stringify(documentSnapshot.data())}`);
  }
});

id

get id(): string;

The ID of the document for which this DocumentSnapshot contains data.

{string} DocumentSnapshot#id

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then((documentSnapshot) => {
  if (documentSnapshot.exists) {
    console.log(`Document found with name '${documentSnapshot.id}'`);
  }
});

readTime

get readTime(): Timestamp;

The time this snapshot was read.

{Timestamp} DocumentSnapshot#readTime

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then(documentSnapshot => {
  let readTime = documentSnapshot.readTime;
  console.log(`Document read at '${readTime.toDate()}'`);
});

ref

get ref(): DocumentReference<T>;

A [DocumentReference]DocumentReference for the document stored in this snapshot.

{DocumentReference} DocumentSnapshot#ref

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then((documentSnapshot) => {
  if (documentSnapshot.exists) {
    console.log(`Found document at '${documentSnapshot.ref.path}'`);
  }
});

updateTime

get updateTime(): Timestamp | undefined;

The time the document was last updated (at the time the snapshot was generated). Undefined for documents that don't exist.

{Timestamp|undefined} DocumentSnapshot#updateTime

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then(documentSnapshot => {
  if (documentSnapshot.exists) {
    let updateTime = documentSnapshot.updateTime;
    console.log(`Document updated at '${updateTime.toDate()}'`);
  }
});

Methods

data()

data(): T | undefined;

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

Returns

Type	Description
T \| undefined	{T\|undefined} An object containing all fields in the document or 'undefined' if the document doesn't exist.

Example


let documentRef = firestore.doc('col/doc');

documentRef.get().then(documentSnapshot => {
  let data = documentSnapshot.data();
  console.log(`Retrieved data: ${JSON.stringify(data)}`);
});

get(field)

get(field: string | FieldPath): any;

Retrieves the field specified by field.

Parameter

Name	Description
field	`string \| FieldPath` The field path (e.g. 'foo' or 'foo.bar') to a specific field.

Returns

Type	Description
any	{*} The data at the specified field location or undefined if no such field exists.

Example


let documentRef = firestore.doc('col/doc');

documentRef.set({ a: { b: 'c' }}).then(() => {
  return documentRef.get();
}).then(documentSnapshot => {
  let field = documentSnapshot.get('a.b');
  console.log(`Retrieved field value: ${field}`);
});

isEqual(other)

isEqual(other: firestore.DocumentSnapshot<T>): boolean;

Returns true if the document's data and path in this DocumentSnapshot is equal to the provided value.

Parameter

Name	Description
other	`FirebaseFirestore.DocumentSnapshot<T>` The value to compare against. {boolean} true if this `DocumentSnapshot` is equal to the provided value.

Returns

Type	Description
boolean