如何将 Swift Promise 桥接到 React Native

Question

我正在将 iOS 原生 SDK 集成到 React-Native。我想从 RN 中使用一个名为 SDK.getCardData 的函数。我的第一次尝试是在闭包内调用resolve 和reject：

import Foundation
import SDK

@objc(SwiftComponentManager)
class SwiftComponentManager: NSObject {
  
  @objc
  func getCardData(_ resolve: RCTPromiseResolveBlock, rejecter reject: RCTPromiseRejectBlock) -> Void {
    let cardId: String = "test"
    let secret: String = "test"

    SDK.getCardData(cardId, secret: secret) { (cardData, error) in
      if (error != nil) {
        reject(String(format: "Card data request failed: %@", error!.localizedDescription))
      } else {
        let pan = cardData!.pan
        let cvv = cardData!.cvv

        resolve(String(format: "Card data fetched successfully, pan: %@, cvv: %@", pan, cvv))
      }
    }
  }

  @objc func testMethod() -> Void {
    print("This Does appear")
  }
}

不幸的是，这会引发以下错误：escaping closure captures non-escaping parameter 'resolve'。

第二次尝试：

import Foundation
import SDK
import Promises

@objc(SwiftComponentManager)
class SwiftComponentManager: NSObject {
  
  @objc
  func getCardData(_ resolve: RCTPromiseResolveBlock, rejecter reject: RCTPromiseRejectBlock) -> Promise<CardData?> {
    let cardId: String = "test"
    let secret: String = "test"
    let promise = Promise<CardData?>()

    SDK.getCardData(cardId, secret: secret) { (cardData, error) in
      if (error != nil) {
        promise.reject(error)
      } else {
        let pan = cardData!.pan
        let cvv = cardData!.cvv

        promise.resolve(cardData)
      }
    }
    
    return promise
  }

  @objc func testMethod() -> Void {
    print("This Does appear")
  }
}

如何正确调用resolve & reject？函数返回Void、more here很重要。

Answer 1

找到answer，只需在参数中添加@escaping：

@objc func fling(_ options: NSDictionary, resolver resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) -> Void {
...