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FirebaseFirestore Framework Reference

WriteBatch

class WriteBatch : NSObject

A write batch is used to perform multiple writes as a single atomic unit.

A WriteBatch object can be acquired by calling Firestore.batch(). It provides methods for adding writes to the write batch. None of the writes will be committed (or visible locally) until WriteBatch.commit() is called.

Unlike transactions, write batches are persisted offline and therefore are preferable when you don’t need to condition your writes on read data.

  • Writes to the document referred to by document. 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(_ data: [String : Any], forDocument document: FIRDocumentReference) -> WriteBatch

    Parameters

    data

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

    A reference to the document whose data should be overwritten.

    Return Value

    This WriteBatch instance. Used for chaining method calls.

  • Writes to the document referred to by document. If the document doesn’t yet exist, this method creates it and then sets the data. If you pass merge:true, the provided data will be merged into any existing document.

    Declaration

    Swift

    func setData(_ data: [String : Any], forDocument document: FIRDocumentReference, merge: Bool) -> WriteBatch

    Parameters

    data

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

    A reference to the document whose data should be overwritten.
    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.

    Return Value

    This WriteBatch instance. Used for chaining method calls.

  • 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(_ data: [String : Any], forDocument document: FIRDocumentReference, mergeFields: [Any]) -> WriteBatch

    Parameters

    data

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

    A reference to the document whose data should be overwritten.
    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.

    Return Value

    This WriteBatch instance. Used for chaining method calls.

  • Updates fields in the document referred to by document. If document does not exist, the write batch will fail.

    Declaration

    Swift

    func updateData(_ fields: [AnyHashable : Any], forDocument document: FIRDocumentReference) -> WriteBatch

    Parameters

    fields

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

    A reference to the document whose data should be updated.

    Return Value

    This WriteBatch instance. Used for chaining method calls.

  • Deletes the document referred to by document.

    Declaration

    Swift

    func deleteDocument(_ document: FIRDocumentReference) -> WriteBatch

    Parameters

    document

    A reference to the document that should be deleted.

    Return Value

    This WriteBatch instance. Used for chaining method calls.

  • Commits all of the writes in this write batch as a single atomic unit.

    Declaration

    Swift

    func commit()

  • Commits all of the writes in this write batch as a single atomic unit.

    Declaration

    Swift

    func commit() async throws

    Parameters

    completion

    A block to be called once all of the writes in the batch have been successfully written to the backend as an atomic unit. 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.

  • Encodes an instance of Encodable and overwrites the encoded data to the document referred by doc. 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

    @discardableResult
func setData<T: Encodable>(from value: T,
                           forDocument doc: DocumentReference,
                           encoder: Firestore.Encoder = Firestore
                             .Encoder()) throws -> WriteBatch

    Parameters

    value

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

    The encoder instance to use to run the encoding.
    doc

    The document to create/overwrite the encoded data to.

    Return Value

    This instance of WriteBatch. Used for chaining method calls.

  • Encodes an instance of Encodable and overwrites the encoded data to the document referred by doc. 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

    @discardableResult
func setData<T: Encodable>(from value: T,
                           forDocument doc: DocumentReference,
                           merge: Bool,
                           encoder: Firestore.Encoder = Firestore
                             .Encoder()) throws -> WriteBatch

    Parameters

    value

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

    The document to create/overwrite the encoded data to.
    merge

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

    The encoder instance to use to run the encoding.

    Return Value

    This instance of WriteBatch. Used for chaining method calls.

  • Encodes an instance of Encodable and writes the encoded data to the document referred by doc 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

    @discardableResult
func setData<T: Encodable>(from value: T,
                           forDocument doc: DocumentReference,
                           mergeFields: [Any],
                           encoder: Firestore.Encoder = Firestore
                             .Encoder()) throws -> WriteBatch

    Parameters

    value

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

    The document to create/overwrite the encoded data to.
    mergeFields

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

    The encoder instance to use to run the encoding.

    Return Value

    This instance of WriteBatch. Used for chaining method calls.