Class DocumentReference (3.8.2)

public class DocumentReference

A DocumentReference refers to a document location in a Firestore database and can be used to write, read, or listen to the location. There may or may not exist a document at the referenced location. A DocumentReference can also be used to create a CollectionReference to a subcollection.

Subclassing Note: Firestore classes are not meant to be subclassed except for use in test mocks. Subclassing is not supported in production code and new SDK releases may break code that does so.

Inheritance

Object > DocumentReference

Inherited Members

Object.clone()

Object.equals(Object)

Object.finalize()

Object.getClass()

Object.hashCode()

Object.notify()

Object.notifyAll()

Object.toString()

Object.wait()

Object.wait(long)

Object.wait(long,int)

Methods

addSnapshotListener(EventListener<DocumentSnapshot> listener)

public ListenerRegistration addSnapshotListener(EventListener<DocumentSnapshot> listener)

Starts listening to the document referenced by this DocumentReference.

Parameter

Name	Description
`listener`	`EventListener<DocumentSnapshot>` The event listener that will be called with the snapshots.

Returns

Type	Description
`ListenerRegistration`	A registration object that can be used to remove the listener.

addSnapshotListener(Executor executor, EventListener<DocumentSnapshot> listener)

public ListenerRegistration addSnapshotListener(Executor executor, EventListener<DocumentSnapshot> listener)

Starts listening to the document referenced by this DocumentReference.

Parameters

Name	Description
`executor`	`Executor` The executor to use to call the listener.
`listener`	`EventListener<DocumentSnapshot>` The event listener that will be called with the snapshots.

Returns

Type	Description
`ListenerRegistration`	A registration object that can be used to remove the listener.

collection(String collectionPath)

public CollectionReference collection(String collectionPath)

Gets a CollectionReference instance that refers to the collection that is a child of this document.

Parameter

Name	Description
`collectionPath`	`String` A relative and slash-separated path to a collection.

Returns

Type	Description
`CollectionReference`	The CollectionReference instance.

create(Object pojo)

public ApiFuture<WriteResult> create(Object pojo)

Creates a new Document at the DocumentReference location. It fails the write if the document exists.

Parameter

Name	Description
`pojo`	`Object` The POJO that will be used to populate the document contents.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

create(Map<String,Object> fields)

public ApiFuture<WriteResult> create(Map<String,Object> fields)

Creates a new Document at the DocumentReference's Location. It fails the write if the document exists.

Parameter

Name	Description
`fields`	`Map<String,Object>` A map of the fields and values for the document.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

delete()

public ApiFuture<WriteResult> delete()

Deletes the document referred to by this DocumentReference.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the delete completes.

delete(Precondition options)

public ApiFuture<WriteResult> delete(Precondition options)

Deletes the document referred to by this DocumentReference.

Parameter

Name	Description
`options`	`Precondition` Preconditions to enforce for this delete.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the delete completes.

equals(Object obj)

public boolean equals(Object obj)

Returns true if this DocumentReference is equal to the provided object.

Parameter

Name	Description
`obj`	`Object` The object to compare against.

Returns

Type	Description
`boolean`	Whether this DocumentReference is equal to the provided object.

Overrides

Object.equals(Object)

get()

public ApiFuture<DocumentSnapshot> get()

Reads the document referenced by this DocumentReference. If the document doesn't exist, the get() will return an an empty DocumentSnapshot.

Returns

Type	Description
`ApiFuture<DocumentSnapshot>`	An ApiFuture that will be resolved with the contents of the Document at this DocumentReference, or a failure if the document does not exist.

get(FieldMask fieldMask)

public ApiFuture<DocumentSnapshot> get(FieldMask fieldMask)

Reads the document referenced by this DocumentReference. If the document doesn't exist, the get(FieldMask fieldMask) will return an empty DocumentSnapshot.

Parameter

Name	Description
`fieldMask`	`FieldMask` A FieldMask object to retrieve the field value

Returns

Type	Description
`ApiFuture<DocumentSnapshot>`	An ApiFuture that will be resolved with the contents of the Document at this DocumentReference, or a failure if the document does not exist

getFirestore()

public Firestore getFirestore()

Returns

Type	Description
`Firestore`

getId()

public String getId()

The id of a document refers to the last component of path pointing to a document, e.g. "document-id" in "projects/project-id/databases/database-id/document-id".

Returns

Type	Description
`String`	The ID of the document.

getParent()

public CollectionReference getParent()

A reference to the Collection to which this DocumentReference belongs to.

Returns

Type	Description
`CollectionReference`	The parent Collection.

getPath()

public String getPath()

A string representing the path of the referenced document (relative to the root of the database).

Returns

Type	Description
`String`	The slash-separated path relative to the root of the database.

hashCode()

public int hashCode()

Returns

Type	Description
`int`

Overrides

Object.hashCode()

listCollections()

public Iterable<CollectionReference> listCollections()

Fetches the subcollections that are direct children of this document.

Returns

Type	Description
`Iterable<CollectionReference>`	An Iterable that can be used to fetch all subcollections.

set(Object pojo)

public ApiFuture<WriteResult> set(Object pojo)

Overwrites the document referred to by this DocumentReference. If no document exists yet, it will be created. If a document already exists, it will be overwritten.

Parameter

Name	Description
`pojo`	`Object` The POJO that will be used to populate the document contents.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

set(Object pojo, SetOptions options)

public ApiFuture<WriteResult> set(Object pojo, SetOptions options)

Writes to the document referred to by this DocumentReference. If the document does not yet exist, it will be created. If you pass SetOptions, the provided data can be merged into an existing document.

Parameters

Name	Description
`pojo`	`Object` The POJO that will be used to populate the document contents.
`options`	`SetOptions` An object to configure the set behavior.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

set(Map<String,Object> fields)

public ApiFuture<WriteResult> set(Map<String,Object> fields)

Overwrites the document referred to by this DocumentReference. If no document exists yet, it will be created. If a document already exists, it will be overwritten.

Parameter

Name	Description
`fields`	`Map<String,Object>` A map of the fields and values for the document.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

set(Map<String,Object> fields, SetOptions options)

public ApiFuture<WriteResult> set(Map<String,Object> fields, SetOptions options)

Parameters

Name	Description
`fields`	`Map<String,Object>` A map of the fields and values for the document.
`options`	`SetOptions` An object to configure the set behavior.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

toString()

public String toString()

Returns

Type	Description
`String`

Overrides

Object.toString()

update(FieldPath fieldPath, Object value, Object[] moreFieldsAndValues)

public ApiFuture<WriteResult> update(FieldPath fieldPath, Object value, Object[] moreFieldsAndValues)

Updates the fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameters

Name	Description
`fieldPath`	`FieldPath` The first field to set
`value`	`Object` The first value to set
`moreFieldsAndValues`	`Object[]` String and Object pairs with more fields to be set.

Returns

Type	Description
`ApiFuture<WriteResult>`	A ApiFuture that will be resolved when the write finishes.

update(Precondition options, FieldPath fieldPath, Object value, Object[] moreFieldsAndValues)

public ApiFuture<WriteResult> update(Precondition options, FieldPath fieldPath, Object value, Object[] moreFieldsAndValues)

Updates the fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameters

Name	Description
`options`	`Precondition` Preconditions to enforce on this update.
`fieldPath`	`FieldPath` The first field to set
`value`	`Object` The first value to set
`moreFieldsAndValues`	`Object[]` String and Object pairs with more fields to be set.

Returns

Type	Description
`ApiFuture<WriteResult>`	A ApiFuture that will be resolved when the write finishes.

update(Precondition options, String field, Object value, Object[] moreFieldsAndValues)

public ApiFuture<WriteResult> update(Precondition options, String field, Object value, Object[] moreFieldsAndValues)

Updates the fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameters

Name	Description
`options`	`Precondition` Preconditions to enforce on this update.
`field`	`String` The first field to set
`value`	`Object` The first value to set
`moreFieldsAndValues`	`Object[]` String and Object pairs with more fields to be set.

Returns

Type	Description
`ApiFuture<WriteResult>`	A ApiFuture that will be resolved when the write finishes.

update(String field, Object value, Object[] moreFieldsAndValues)

public ApiFuture<WriteResult> update(String field, Object value, Object[] moreFieldsAndValues)

Updates the fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameters

Name	Description
`field`	`String` The first field to set
`value`	`Object` The first value to set
`moreFieldsAndValues`	`Object[]` String and Object pairs with more fields to be set.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

update(Map<String,Object> fields)

public ApiFuture<WriteResult> update(Map<String,Object> fields)

Updates fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameter

Name	Description
`fields`	`Map<String,Object>` A Map containing the fields and values with which to update the document.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.

update(Map<String,Object> fields, Precondition options)

public ApiFuture<WriteResult> update(Map<String,Object> fields, Precondition options)

Updates fields in the document referred to by this DocumentReference. If the document doesn't exist yet, the update will fail.

Parameters

Name	Description
`fields`	`Map<String,Object>` A map containing the fields and values with which to update the document.
`options`	`Precondition` Preconditions to enforce on this update.

Returns

Type	Description
`ApiFuture<WriteResult>`	An ApiFuture that will be resolved when the write finishes.