class

DocumentSnapshot

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.

Properties

createTime
exists

id
readTime

ref
updateTime

Methods

data()

get(field)

isEqual(other)

Properties

read-only

createTime (Timestamp or undefined)

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

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()}'`);
  }
});

read-only

exists boolean

True if the document exists.

Example

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

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

read-only

id string

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

Example

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

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

read-only

readTime Timestamp

The time this snapshot was read.

Example

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

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

read-only

ref DocumentReference

A DocumentReference for the document stored in this snapshot.

Example

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

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

read-only

updateTime (Timestamp or undefined)

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

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() → (DocumentData or undefined)

Retrieves all fields in the document as an object. Returns '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)}`);
});

Returns

(DocumentData or undefined)

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

get(field) → any type

Retrieves the field specified by field.

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}`);
});

Parameter

Name	Type	Optional	Description
field	(string or FieldPath)		The field path (e.g. 'foo' or 'foo.bar') to a specific field.

Returns

any type

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

isEqual(other) → boolean

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

Parameter

Name	Type	Optional	Description
other	any type		The value to compare against.

Returns

boolean

true if this DocumentSnapshot is equal to the provided value.