class

QuerySnapshot

Source: reference.js:565

Properties

docs
empty
query
readTime
size

Methods

docChanges()
forEach(callback[, thisArg])
isEqual(other)

new QuerySnapshot()

A QuerySnapshot contains zero or more QueryDocumentSnapshot objects representing the results of a query. The documents can be accessed as an array via the documents property or enumerated using the forEach method. The number of documents can be determined via the empty and size properties.

Properties

read-only

docs  Array of QueryDocumentSnapshot

An array of all the documents in this QuerySnapshot.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.get().then(querySnapshot => {
  let docs = querySnapshot.docs;
  for (let doc of docs) {
    console.log(`Document found at path: ${doc.ref.path}`);
  }
});
read-only

empty  boolean

True if there are no documents in the QuerySnapshot.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.get().then(querySnapshot => {
  if (querySnapshot.empty) {
    console.log('No documents found.');
  }
});
read-only

query  Query

The query on which you called get() or onSnapshot() in order to get this QuerySnapshot.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.limit(10).get().then(querySnapshot => {
  console.log(`Returned first batch of results`);
  let query = querySnapshot.query;
  return query.offset(10).get();
}).then(() => {
  console.log(`Returned second batch of results`);
});

readTime  Timestamp

The time this query snapshot was obtained.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.get().then((querySnapshot) => {
  let readTime = querySnapshot.readTime;
  console.log(`Query results returned at '${readTime.toDate()}'`);
});
read-only

size  number

The number of documents in the QuerySnapshot.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.get().then(querySnapshot => {
  console.log(`Found ${querySnapshot.size} documents.`);
});

Methods

docChanges() → Array of DocumentChange

Returns an array of the documents changes since the last snapshot. If this is the first snapshot, all documents will be in the list as added changes.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.onSnapshot(querySnapshot => {
  let changes = querySnapshot.docChanges();
  for (let change of changes) {
    console.log(`A document was ${change.type}.`);
  }
});
Returns

Array of DocumentChange 

forEach(callback[, thisArg])

Enumerates all of the documents in the QuerySnapshot. This is a convenience method for running the same callback on each QueryDocumentSnapshot that is returned.

Example 

let query = firestore.collection('col').where('foo', '==', 'bar');

query.get().then(querySnapshot => {
  querySnapshot.forEach(documentSnapshot => {
    console.log(`Document found at path: ${documentSnapshot.ref.path}`);
  });
});

Parameters

Name Type Optional Description

callback

function()

 

A callback to be called with a QueryDocumentSnapshot for each document in the snapshot.

thisArg

any type

Yes

The this binding for the callback..

isEqual(other) → boolean

Returns true if the document data in this QuerySnapshot is equal to the provided value.

Parameter

Name Type Optional Description

other

any type

 

The value to compare against.
Returns

boolean 

true if this QuerySnapshot is equal to the provided value.