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FirebaseFirestore Framework Reference

DocumentReference

class DocumentReference : NSObject, @unchecked Sendable

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

  • The ID of the document referred to.

    Declaration

    Swift

    var documentID: String { get }

  • A reference to the collection to which this DocumentReference belongs.

    Declaration

    Swift

    var parent: FIRCollectionReference { get }

  • The Firestore for the Firestore database (useful for performing transactions, etc.).

    Declaration

    Swift

    var firestore: FIRFirestore { get }

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

    Declaration

    Swift

    var path: String { get }

  • Gets a CollectionReference referring to the collection at the specified path, relative to this document.

    Declaration

    Swift

    func collection(_ collectionPath: String) -> FIRCollectionReference

    Parameters

    collectionPath

    The slash-separated relative path of the collection for which to get a CollectionReference.

    Return Value

    The CollectionReference at the specified collectionPath.

Writing Data

  • Writes to the document referred to by DocumentReference. If the document doesn’t yet exist, this method creates it and then sets the data. If the document exists, this method overwrites the document data with the new values.

    Declaration

    Swift

    func setData(_ documentData: [String : Any])

    Parameters

    documentData

    A Dictionary that contains the fields and data to write to the document.

  • Writes to the document referred to by this DocumentReference. If the document does not yet exist, it will be created. If you pass merge:true, the provided data will be merged into any existing document.

    Declaration

    Swift

    func setData(_ documentData: [String : Any], merge: Bool)

    Parameters

    documentData

    A Dictionary that contains the fields and data to write to the document.
    merge

    Whether to merge the provided data into any existing document. If enabled, all omitted fields remain untouched. If your input sets any field to an empty dictionary, any nested field is overwritten.

  • Writes to the document referred to by document and only replace the fields specified under mergeFields. Any field that is not specified in mergeFields is ignored and remains untouched. If the document doesn’t yet exist, this method creates it and then sets the data.

    It is an error to include a field in mergeFields that does not have a corresponding value in the data dictionary.

    Declaration

    Swift

    func setData(_ documentData: [String : Any], mergeFields: [Any])

    Parameters

    documentData

    A Dictionary containing the fields that make up the document to be written.
    mergeFields

    An Array that contains a list of String or FieldPath elements specifying which fields to merge. Fields can contain dots to reference nested fields within the document. If your input sets any field to an empty dictionary, any nested field is overwritten.

  • Overwrites the document referred to by this DocumentReference. If no document exists, it is created. If a document already exists, it is overwritten.

    Declaration

    Swift

    func setData(_ documentData: [String : Any]) async throws

    Parameters

    documentData

    A Dictionary containing the fields that make up the document to be written.
    completion

    A block to execute once the document has been successfully written to the server. This block will not be called while the client is offline, though local changes will be visible immediately.

  • Writes to the document referred to by this DocumentReference. If the document does not yet exist, it will be created. If you pass merge:true, the provided data will be merged into any existing document.

    Declaration

    Swift

    func setData(_ documentData: [String : Any], merge: Bool) async throws

    Parameters

    documentData

    A Dictionary containing the fields that make up the document to be written.
    merge

    Whether to merge the provided data into any existing document. If your input sets any field to an empty dictionary, any nested field is overwritten.
    completion

    A block to execute once the document has been successfully written to the server. This block will not be called while the client is offline, though local changes will be visible immediately.

  • Writes to the document referred to by document and only replace the fields specified under mergeFields. Any field that is not specified in mergeFields is ignored and remains untouched. If the document doesn’t yet exist, this method creates it and then sets the data.

    It is an error to include a field in mergeFields that does not have a corresponding value in the data dictionary.

    Declaration

    Swift

    func setData(_ documentData: [String : Any], mergeFields: [Any]) async throws

    Parameters

    documentData

    A Dictionary containing the fields that make up the document to be written.
    mergeFields

    An Array that contains a list of String or FieldPath elements specifying which fields to merge. Fields can contain dots to reference nested fields within the document. If your input sets any field to an empty dictionary, any nested field is overwritten.
    completion

    A block to execute once the document has been successfully written to the server. This block will not be called while the client is offline, though local changes will be visible immediately.

  • Updates fields in the document referred to by this DocumentReference. If the document does not exist, the update fails (specify a completion block to be notified).

    Declaration

    Swift

    func updateData(_ fields: [AnyHashable : Any])

    Parameters

    fields

    A Dictionary containing the fields (expressed as an String or FieldPath) and values with which to update the document.

  • Updates fields in the document referred to by this DocumentReference. If the document does not exist, the update fails and the specified completion block receives an error.

    Declaration

    Swift

    func updateData(_ fields: [AnyHashable : Any]) async throws

    Parameters

    fields

    A Dictionary containing the fields (expressed as a String or FieldPath) and values with which to update the document.
    completion

    A block to execute when the update is complete. If the update is successful the error parameter will be nil, otherwise it will give an indication of how the update failed. This block will only execute when the client is online and the commit has completed against the server. The completion handler will not be called when the device is offline, though local changes will be visible immediately.

  • Deletes the document referred to by this DocumentReference.

    Declaration

    Swift

    func delete()

  • Deletes the document referred to by this DocumentReference.

    Declaration

    Swift

    func delete() async throws

    Parameters

    completion

    A block to execute once the document has been successfully written to the server. This block will not be called while the client is offline, though local changes will be visible immediately.

Retrieving Data

  • Reads the document referenced by this DocumentReference.

    This method attempts to provide up-to-date data when possible by waiting for data from the server, but it may return cached data or fail if you are offline and the server cannot be reached. See the getDocument(source:completion:) method to change this behavior.

    Declaration

    Swift

    func getDocument() async throws -> FIRDocumentSnapshot

    Parameters

    completion

    a block to execute once the document has been successfully read.

  • Reads the document referenced by this DocumentReference.

    Declaration

    Swift

    func getDocument(source: FirestoreSource) async throws -> FIRDocumentSnapshot

    Parameters

    source

    indicates whether the results should be fetched from the cache only (Source.cache), the server only (Source.server), or to attempt the server and fall back to the cache (Source.default).
    completion

    a block to execute once the document has been successfully read.

  • Attaches a listener for DocumentSnapshot events.

    Declaration

    Swift

    func addSnapshotListener(_ listener: @escaping (FIRDocumentSnapshot?, (any Error)?) -> Void) -> any ListenerRegistration

    Parameters

    listener

    The listener to attach.

    Return Value

    A ListenerRegistration that can be used to remove this listener.

  • Attaches a listener for DocumentSnapshot events.

    Declaration

    Swift

    func addSnapshotListener(includeMetadataChanges: Bool, listener: @escaping (FIRDocumentSnapshot?, (any Error)?) -> Void) -> any ListenerRegistration

    Parameters

    includeMetadataChanges

    Whether metadata-only changes (i.e. only DocumentSnapshot.metadata changed) should trigger snapshot events.
    listener

    The listener to attach.

    Return Value

    A ListenerRegistration that can be used to remove this listener.

  • Attaches a listener for DocumentSnapshot events.

    Declaration

    Swift

    func addSnapshotListener(options: SnapshotListenOptions, listener: @escaping (FIRDocumentSnapshot?, (any Error)?) -> Void) -> any ListenerRegistration

    Parameters

    options

    Sets snapshot listener options, including whether metadata-only changes should trigger snapshot events, the source to listen to, the executor to use to call the listener, or the activity to scope the listener to.
    listener

    The listener to attach.

    Return Value

    A ListenerRegistration that can be used to remove this listener.

  • Declaration

    Swift

    public static func wrap(_ documentReference: DocumentReference) throws -> Self

  • Fetches and decodes the document referenced by this DocumentReference.

    This allows users to retrieve a Firestore document and have it decoded to an instance of caller-specified type as follows:

    ref.getDocument(as: Book.self) { result in
  do {
    let book = try result.get()
  } catch {
    // Handle error
  }
}

    This method attempts to provide up-to-date data when possible by waiting for data from the server, but it may return cached data or fail if you are offline and the server cannot be reached. If T denotes an optional type, the method returns a successful status with a value of nil for non-existing documents.

    Declaration

    Swift

    func getDocument<T: Decodable>(as type: T.Type,
                               with serverTimestampBehavior: ServerTimestampBehavior =
                                 .none,
                               decoder: Firestore.Decoder = .init(),
                               source: FirestoreSource = .default,
                               completion: @escaping (Result<T, Error>) -> Void)

    Parameters

    as

    A Decodable type to convert the document fields to.
    serverTimestampBehavior

    Configures how server timestamps that have not yet been set to their final value are returned from the snapshot.
    decoder

    The decoder to use to convert the document. Defaults to use the default decoder.
    source

    Indicates whether the results should be fetched from the cache only (Source.cache), the server only (Source.server), or to attempt the server and fall back to the cache (Source.default).
    completion

    The closure to call when the document snapshot has been fetched and decoded.

  • Fetches and decodes the document referenced by this DocumentReference.

    This allows users to retrieve a Firestore document and have it decoded to an instance of caller-specified type as follows:

    do {
  let book = try await ref.getDocument(as: Book.self)
} catch {
  // Handle error
}

    This method attempts to provide up-to-date data when possible by waiting for data from the server, but it may return cached data or fail if you are offline and the server cannot be reached. If T denotes an optional type, the method returns a successful status with a value of nil for non-existing documents.

    Declaration

    Swift

    @available(iOS 13, tvOS 13, macOS 10.15, watchOS 7, *)
func getDocument<T: Decodable>(as type: T.Type,
                               with serverTimestampBehavior: ServerTimestampBehavior =
                                 .none,
                               decoder: Firestore.Decoder = .init(),
                               source: FirestoreSource = .default) async throws -> T

    Parameters

    as

    A Decodable type to convert the document fields to.
    serverTimestampBehavior

    Configures how server timestamps that have not yet been set to their final value are returned from the snapshot.
    decoder

    The decoder to use to convert the document. Defaults to use the default decoder.
    source

    Indicates whether the results should be fetched from the cache only (Source.cache), the server only (Source.server), or to attempt the server and fall back to the cache (Source.default).

    Return Value

    This instance of the supplied Decodable type T.

  • Encodes an instance of Encodable and overwrites the encoded data to the document referred by this DocumentReference. If no document exists, it is created. If a document already exists, it is overwritten.

    See Firestore.Encoder for more details about the encoding process.

    Declaration

    Swift

    func setData<T: Encodable>(from value: T,
                           encoder: Firestore.Encoder = Firestore.Encoder(),
                           completion: ((Error?) -> Void)? = nil) throws

    Parameters

    value

    An instance of Encodable to be encoded to a document.
    encoder

    An encoder instance to use to run the encoding.
    completion

    A closure to execute once the document has been successfully written to the server. This closure will not be called while the client is offline, though local changes will be visible immediately.

  • Encodes an instance of Encodable and overwrites the encoded data to the document referred by this DocumentReference. If no document exists, it is created. If a document already exists, it is overwritten. If you pass merge:true, the provided Encodable will be merged into any existing document.

    See Firestore.Encoder for more details about the encoding process.

    Declaration

    Swift

    func setData<T: Encodable>(from value: T,
                           merge: Bool,
                           encoder: Firestore.Encoder = Firestore.Encoder(),
                           completion: ((Error?) -> Void)? = nil) throws

    Parameters

    value

    An instance of Encodable to be encoded to a document.
    merge

    Whether to merge the provided Encodable into any existing document.
    encoder

    An encoder instance to use to run the encoding.
    completion

    A closure to execute once the document has been successfully written to the server. This closure will not be called while the client is offline, though local changes will be visible immediately.

  • Encodes an instance of Encodable and writes the encoded data to the document referred by this DocumentReference by only replacing the fields specified under mergeFields. Any field that is not specified in mergeFields is ignored and remains untouched. If the document doesn’t yet exist, this method creates it and then sets the data.

    It is an error to include a field in mergeFields that does not have a corresponding field in the Encodable.

    See Firestore.Encoder for more details about the encoding process.

    Declaration

    Swift

    func setData<T: Encodable>(from value: T,
                           mergeFields: [Any],
                           encoder: Firestore.Encoder = Firestore.Encoder(),
                           completion: ((Error?) -> Void)? = nil) throws

    Parameters

    value

    An instance of Encodable to be encoded to a document.
    mergeFields

    Array of String or FieldPath elements specifying which fields to merge. Fields can contain dots to reference nested fields within the document.
    encoder

    An encoder instance to use to run the encoding.
    completion

    A closure to execute once the document has been successfully written to the server. This closure will not be called while the client is offline, though local changes will be visible immediately.