Change class

The Cloud Functions interface for events that change state, such as Realtime Database or Cloud Firestore onWrite and onUpdate events.

For more information about the format used to construct Change objects, see below.

Signature:

export declare class Change<T> 

Constructors

Constructor Modifiers Description
(constructor)(before, after) Constructs a new instance of the Change class

Properties

Property Modifiers Type Description
after T
before T

Methods

Method Modifiers Description
fromJSON(json, customizer) static Factory method for creating a Change from JSON and an optional customizer function to be applied to both the before and the after fields.
fromObjects(before, after) static Factory method for creating a Change from a before object and an after object.

Change.(constructor)

Constructs a new instance of the Change class

Signature:

constructor(before: T, after: T);

Parameters

Parameter Type Description
before T
after T

Change.after

Signature:

after: T;

Change.before

Signature:

before: T;

Change.fromJSON()

Factory method for creating a Change from JSON and an optional customizer function to be applied to both the before and the after fields.

Signature:

static fromJSON<T>(json: ChangeJson, customizer?: (x: any) => T): Change<T>;

Parameters

Parameter Type Description
json ChangeJson
customizer (x: any) => T

Returns:

Change<T>

Change.fromObjects()

Factory method for creating a Change from a before object and an after object.

Signature:

static fromObjects<T>(before: T, after: T): Change<T>;

Parameters

Parameter Type Description
before T
after T

Returns:

Change<T>