A DocumentSnapshot contains data read from a document in your Firestore database. The data can be extracted with .data() or .get(<field>) 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() method to explicitly verify a document's existence.
Signature:
export declare class DocumentSnapshot<AppModelType = DocumentData, DbModelType extends DocumentData = DocumentData>
Constructors
| Constructor | Modifiers | Description |
|---|---|---|
| (constructor)() | Constructs a new instance of the DocumentSnapshot class |
Properties
| Property | Modifiers | Type | Description |
|---|---|---|---|
| id | string | Property of the DocumentSnapshot that provides the document's ID. |
|
| ref | DocumentReference<AppModelType, DbModelType> | The DocumentReference for the document included in the DocumentSnapshot. |
Methods
| Method | Modifiers | Description |
|---|---|---|
| data() | Retrieves all fields in the document as an Object. Returns undefined if the document doesn't exist. |
|
| exists() | Signals whether or not the document at the snapshot's location exists. | |
| get(fieldPath) | Retrieves the field specified by fieldPath. Returns undefined if the document or field doesn't exist. |
DocumentSnapshot.(constructor)
Constructs a new instance of the DocumentSnapshot class
Signature:
protected constructor();
DocumentSnapshot.id
Property of the DocumentSnapshot that provides the document's ID.
Signature:
get id(): string;
DocumentSnapshot.ref
The DocumentReference for the document included in the DocumentSnapshot.
Signature:
get ref(): DocumentReference<AppModelType, DbModelType>;
DocumentSnapshot.data()
Retrieves all fields in the document as an Object. Returns undefined if the document doesn't exist.
Signature:
data(): AppModelType | undefined;
Returns:
AppModelType | undefined
An Object containing all fields in the document or undefined if the document doesn't exist.
DocumentSnapshot.exists()
Signals whether or not the document at the snapshot's location exists.
Signature:
exists(): this is QueryDocumentSnapshot<AppModelType, DbModelType>;
Returns:
this is QueryDocumentSnapshot<AppModelType, DbModelType>
true if the document exists.
DocumentSnapshot.get()
Retrieves the field specified by fieldPath. Returns undefined if the document or field doesn't exist.
Signature:
get(fieldPath: string | FieldPath): any;
Parameters
| Parameter | Type | Description |
|---|---|---|
| fieldPath | string | FieldPath | The path (for example 'foo' or 'foo.bar') to a specific field. |
Returns:
any
The data at the specified field location or undefined if no such field exists in the document.