QueryResult

public class QueryResult<T>

Represent the result of an asynchronous query executed by FaunaDB.

Note

All methods available to handle QueryResult success or failure will optionally receive a DispatchQueue. Remember, the only DispatchQueue allowed to update the UI is DispatchQueue.main.

  • Maps the result returned by the server using the function provided.

    Declaration

    Swift

    public func map<A>(at queue: DispatchQueue? = nil, _ transform: @escaping (T) throws -> A) -> QueryResult<A>

    Parameters

    queue

    The dispatch queue in which the transformation will be performed.
    transform

    The transformation to be applied on the result value.

    Return Value

    A QueryResult containing the transformed value.

  • Flat maps the result returned by the server using the function provided.

    Declaration

    Swift

    public func flatMap<A>(at queue: DispatchQueue? = nil, _ transform: @escaping (T) throws -> QueryResult<A>) -> QueryResult<A>

    Parameters

    queue

    The dispatch queue in which the transformation will be performed.
    transform

    The transformation to be applied on the result value.

    Return Value

    A QueryResult containing the transformed value.

  • Apply a transformation if an error has occurred during the query execution.

    If mapErr returns a value, the resulting QueryResult will be transformed into a success result. If you wish to handle an error but still return a failing QueryResult, you must rethrow an exception.

    For example:

    // Revover from an error
client.query(/* some query

    Declaration

    Swift

    public func mapErr(at queue: DispatchQueue? = nil, _ transform: @escaping (Error) throws -> T) -> QueryResult

    Parameters

    queue
    transform

  • Apply a transformation if an error has occurred during the query execution.

    If flatMapErr returns a value, the resulting QueryResult will be transformed into a success result. If you wish to handle an error but still return a failing QueryResult, you must rethrow an exception.

    For example:

    // Revover from an error
client.query(/* some query

    Declaration

    Swift

    public func flatMapErr(at queue: DispatchQueue? = nil, _ transform: @escaping (Error) throws -> QueryResult) -> QueryResult

    Parameters

    queue
    transform

  • Execute the provided callback when the resulting QueryResult is successful.

    Declaration

    Swift

    public func onSuccess(at queue: DispatchQueue? = nil, _ callback: @escaping (T) throws -> Void) -> QueryResult

    Parameters

    queue

    The dispatch queue in which the callback will be executed.
    callback

    The callback to be called when the resulting value is available.

  • Execute the provided callback when an error occurs during the query execution.

    Declaration

    Swift

    public func onFailure(at queue: DispatchQueue? = nil, _ callback: @escaping (Error) throws -> Void) -> QueryResult

    Parameters

    queue

    The dispatch queue in which the callback will be executed.
    callback

    The callback to be called when an error occurs.

  • Blocks the current thread, waiting for the query to be executed.

    Note

    This method is discouraged due to its blocking nature. Prefer map, onSuccess, and their variations to prevent your code from blocking your application.

    Throws

    Any exception that might have happened during the query execution.

    Declaration

    Swift

    public func await(timeout: DispatchTime) throws -> T

    Parameters

    timeout

    How long it should wait for the result to come back.

    Return Value

    The resulting query value.