FieldValue

arrayRemove(...elements) → FieldValue

Returns a special value that can be used with set(), create() or update() that tells the server to remove the given elements from any array value that already exists on the server. All instances of each element specified will be removed from the array. If the field being modified is not already an array it will be overwritten with an empty array.

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

documentRef.update(
  'array', Firestore.FieldValue.arrayRemove('foo')
).then(() => {
  return documentRef.get();
}).then(doc => {
  // doc.get('array') no longer contains field 'foo'
});

Returns

FieldValue 

The FieldValue sentinel for use in a call to set(), create() or update().

arrayUnion(...elements) → FieldValue

Returns a special value that can be used with set(), create() or update() that tells the server to union the given elements with any array value that already exists on the server. Each specified element that doesn't already exist in the array will be added to the end. If the field being modified is not already an array it will be overwritten with an array containing exactly the specified elements.

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

documentRef.update(
  'array', Firestore.FieldValue.arrayUnion('foo')
).then(() => {
  return documentRef.get();
}).then(doc => {
  // doc.get('array') contains field 'foo'
});

Returns

FieldValue 

The FieldValue sentinel for use in a call to set(), create() or update().

delete() → FieldValue

Returns a sentinel for use with update() or set() with {merge:true} to mark a field for deletion.

let documentRef = firestore.doc('col/doc');
let data = { a: 'b', c: 'd' };

documentRef.set(data).then(() => {
  return documentRef.update({a: Firestore.FieldValue.delete()});
}).then(() => {
  // Document now only contains { c: 'd' }
});

Returns

FieldValue 

The sentinel value to use in your objects.

increment(n) → FieldValue

Returns a special value that can be used with set(), create() or update() that tells the server to increment the the field's current value by the given value.

If either current field value or the operand uses floating point precision, both values will be interpreted as floating point numbers and all arithmetic will follow IEEE 754 semantics. Otherwise, integer precision is kept and the result is capped between -2^63 and 2^63-1.

If the current field value is not of type 'number', or if the field does not yet exist, the transformation will set the field to the given value.

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

documentRef.update(
  'counter', Firestore.FieldValue.increment(1)
).then(() => {
  return documentRef.get();
}).then(doc => {
  // doc.get('counter') was incremented
});

Returns

FieldValue 

The FieldValue sentinel for use in a call to set(), create() or update().

serverTimestamp() → FieldValue

Returns a sentinel used with set(), create() or update() to include a server-generated timestamp in the written data.

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

documentRef.set({
  time: Firestore.FieldValue.serverTimestamp()
}).then(() => {
  return documentRef.get();
}).then(doc => {
  console.log(`Server time set to ${doc.get('time')}`);
});

Returns

FieldValue 

The FieldValue sentinel for use in a call to set(), create() or update().

isEqual(other) → boolean

Returns true if this FieldValue is equal to the provided value.

let fieldValues = [
  Firestore.FieldValue.increment(-1.0),
  Firestore.FieldValue.increment(-1),
  Firestore.FieldValue.increment(-0.0),
  Firestore.FieldValue.increment(-0),
  Firestore.FieldValue.increment(0),
  Firestore.FieldValue.increment(0.0),
  Firestore.FieldValue.increment(1),
  Firestore.FieldValue.increment(1.0)
];

let equal = 0;
for (let i = 0; i < fieldValues.length; ++i) {
  for (let j = i + 1; j < fieldValues.length; ++j) {
    if (fieldValues[i].isEqual(fieldValues[j])) {
      ++equal;
    }
  }
}
console.log(`Found ${equal} equalities.`);

Returns

boolean 

true if this FieldValue is equal to the provided value.