mirror of
https://github.com/google/promises
synced 2026-11-10 22:36:00 +05:45
61 lines
2.0 KiB
Swift
61 lines
2.0 KiB
Swift
// Copyright 2018 Google Inc. All rights reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at:
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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import Foundation
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public extension Promise {
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public typealias AsyncProgress = (
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@escaping (Value) -> Void,
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@escaping (Error) -> Void,
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Progress
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) throws -> Void
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public typealias Async = (@escaping (Value) -> Void, @escaping (Error) -> Void) throws -> Void
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/// Creates a pending promise and executes `work` block asynchronously on the given `queue`.
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/// - parameters:
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/// - queue: A queue to invoke the `work` block on.
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/// - work: A block to perform any operations needed to resolve the promise.
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public convenience init(
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on queue: DispatchQueue = .promises,
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progressUnits: Int64 = 1,
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_ work: @escaping AsyncProgress
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) {
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let objCPromise = ObjCPromise<AnyObject>.__onQueue(
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queue,
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progressUnits: progressUnits
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) { fulfill, reject, progress in
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do {
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try work({ value in
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if let error = value as? NSError {
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reject(error)
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} else {
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fulfill(Promise<Value>.asAnyObject(value))
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}
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}, reject, progress)
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} catch let error {
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reject(error as NSError)
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}
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}
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self.init(objCPromise)
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// Keep Swift wrapper alive for chained promise until `ObjCPromise` counterpart is resolved.
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objCPromise.__pendingObjects?.add(self)
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}
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public convenience init(on queue: DispatchQueue = .promises, _ work: @escaping Async) {
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self.init(on: queue) { fulfill, reject, _ in
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try work(fulfill, reject)
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}
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}
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}
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