new FieldValue
()
Sentinel values that can be used when writing documents with set(), create()
or update().
Methods
isEqual
(other)
→ {boolean}
Returns true if this
FieldValue
is equal to the provided value.
Parameters:
| Name
|
Type
|
Description
|
other
|
*
|
The value to compare against.
|
Returns:
| Type
|
Description
|
|
boolean
|
true if this
FieldValue
is equal to the provided value.
|
Example
```
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.`);
```
(static)
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.
Parameters:
| Name
|
Type
|
Attributes
|
Description
|
elements
|
*
|
<repeatable>
|
The elements to remove from the array.
|
Returns:
| Type
|
Description
|
|
FieldValue
|
The FieldValue sentinel for use in a call to set(),
create() or update().
|
Example
```
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'
});
```
(static)
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.
Parameters:
| Name
|
Type
|
Attributes
|
Description
|
elements
|
*
|
<repeatable>
|
The elements to union into the array.
|
Returns:
| Type
|
Description
|
|
FieldValue
|
The FieldValue sentinel for use in a call to set(),
create() or update().
|
Example
```
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'
});
```
(static)
delete
()
→ {
FieldValue
}
Returns a sentinel for use with update() or set() with {merge:true} to mark
a field for deletion.
Returns:
| Type
|
Description
|
|
FieldValue
|
The sentinel value to use in your objects.
|
Example
```
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' }
});
```
(static)
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.
Parameters:
| Name
|
Type
|
Description
|
n
|
number
|
The value to increment by.
|
Returns:
| Type
|
Description
|
|
FieldValue
|
The FieldValue sentinel for use in a call to set(),
create() or update().
|
Example
```
let documentRef = firestore.doc('col/doc');
documentRef.update(
'counter', Firestore.FieldValue.increment(1)
).then(() => {
return documentRef.get();
}).then(doc => {
// doc.get('counter') was incremented
});
```
(static)
serverTimestamp
()
→ {
FieldValue
}
Returns a sentinel used with set(), create() or update() to include a
server-generated timestamp in the written data.
Returns:
| Type
|
Description
|
|
FieldValue
|
The FieldValue sentinel for use in a call to set(),
create() or update().
|
Example
```
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')}`);
});
```
(static)
vector
(values)
Creates a new
VectorValue
constructed with a copy of the given array of numbers.
Parameters:
| Name
|
Type
|
Description
|
values
|
|
Create a
VectorValue
instance with a copy of this array of numbers.
|
Returns:
| Type
|
Description
|
|
|
A new
VectorValue
constructed with a copy of the given array of numbers.
|
