PromiseLite

public class PromiseLite<Value>

An object that represents the eventual completion or failure of an asynchronous operation, and its resulting value.

  • Creates a promise and executes the given executor.

    Declaration

    Swift

    public convenience init(_ executor: (_ resolve: @escaping (Value) -> Void, _ reject: @escaping (Error) -> Void) throws -> Void)

    Parameters

    executor

    The function to be executed by the constructor, during the process of constructing the promise.

  • Creates a promise and executes the given executor.

    Declaration

    Swift

    public convenience init(_ description: String, executor: (_ resolve: @escaping (Value) -> Void, _ reject: @escaping (Error) -> Void) throws -> Void)

    Parameters

    description

    An optional custom description for the promise, eg. fetchUserProfile. Default description for a promise is "PromiseLite<\(Value.self)>", eg. "PromiseLite<Bool>".
    executor

    The function to be executed by the constructor, during the process of constructing the promise.

  • Returns a promise.

    Declaration

    Swift

    @discardableResult
public func flatMap<NewValue>(_ completion: @escaping (Value) throws -> PromiseLite<NewValue>) -> PromiseLite<NewValue>

    Parameters

    completion

    A completion block that is called if the promise fulfilled.

  • Returns a Promise and deals with rejected cases only.

    The Promise returned by catch() is rejected if the rejection block throws an error or returns a Promise which is itself rejected; otherwise, it is resolved.

    Declaration

    Swift

    @discardableResult
public func flatCatch(_ rejection: @escaping (Error) throws -> PromiseLite) -> PromiseLite

    Parameters

    rejection

    A completion block that is called when the Promise is rejected.

  • Returns a Promise and deals with rejected cases only.

    The Promise returned by catch() is rejected if the rejection block throws an error or returns a Promise which is itself rejected; otherwise, it is resolved.

    Declaration

    Swift

    @discardableResult
public func `catch`(_ rejection: @escaping (Error) throws -> Value) -> PromiseLite

    Parameters

    rejection

    A completion block that is called when the Promise is rejected.

  • Returns a promise. This provides a way for code to be run whether the promise was fulfilled successfully or rejected once the Promise has been dealt with.

    A finally callback will not receive any argument, since there’s no reliable means of determining if the promise was fulfilled or rejected. This use case is for precisely when you do not care about the rejection reason, or the fulfillment value, and so there’s no need to provide it.

    Declaration

    Swift

    @discardableResult
public func flatFinally<NewValue>(_ completion: @escaping () throws -> PromiseLite<NewValue>) -> PromiseLite<NewValue>

    Parameters

    completion

    A completion block that is called if the promise is settled, whether fulfilled or rejected.

  • Returns a promise. This provides a way for code to be run whether the promise was fulfilled successfully or rejected once the Promise has been dealt with.

    A finally callback will not receive any argument, since there’s no reliable means of determining if the promise was fulfilled or rejected. This use case is for precisely when you do not care about the rejection reason, or the fulfillment value, and so there’s no need to provide it.

    Declaration

    Swift

    @discardableResult
public func finally<NewValue>(_ completion: @escaping () throws -> NewValue) -> PromiseLite<NewValue>

    Parameters

    completion

    A completion block that is called if the promise is settled, whether fulfilled or rejected.

  • Returns a promise.

    Declaration

    Swift

    @discardableResult
public func map<NewValue>(_ completion: @escaping (Value) throws -> NewValue) -> PromiseLite<NewValue>

    Parameters

    completion

    A completion block that is called if the promise fulfilled.

  • Returns a Promise that is resolved with a given value.

    Declaration

    Swift

    public static func resolve(_ value: Value) -> PromiseLite<Value>

    Parameters

    value

    The argument to be resolved by this Promise.

  • Returns a Promise that is resolved with a given value.

    Declaration

    Swift

    public static func resolve(description: String, _ value: Value) -> PromiseLite<Value>

    Parameters

    description

    An optional custom description for the promise, eg. fetchUserProfile.
    value

    The argument to be resolved by this Promise.

  • Returns a Promise that is rejected with a given reason.

    Declaration

    Swift

    public static func reject(_ error: Error) -> PromiseLite<Value>

    Parameters

    error

    The reason why this Promise rejected.

  • Returns a Promise that is rejected with a given reason.

    Declaration

    Swift

    public static func reject(description: String, _ error: Error) -> PromiseLite<Value>

    Parameters

    description

    An optional custom description for the promise, eg. fetchUserProfile.
    error

    The reason why this Promise rejected.