ImageScout Frame

文件结构:

ImageCount 图片观察对象
ScoutOperation  图片操作队列
ImageParser  图片解析
SessionDelegate  图片下载代理

具体执行过程:

 1、let scout = ImageScout()
2、 scout.scoutImage(atURL: imagePath) { (error, size, type) -> () in

设置返回时的回调
3、 operation.completionBlock = { [weak self] in
      completion(operation.error, operation.size, operation.type)
      self?.operations[urlString] = nil
    }

请求数据时 拼接获得到的数据
4、extension ImageScout {
  func didReceive(data: Data, task: URLSessionDataTask) {
    guard let requestURL = task.currentRequest?.url?.absoluteString else { return }
    guard let operation = operations[requestURL] else { return }

    operation.append(data)
    }

//完成时数据开始解析
  func didComplete(with error: NSError?, task: URLSessionDataTask) {
    guard let requestURL = task.currentRequest?.url?.absoluteString,
      let operation = operations[requestURL]
      else { return }

    let completionError = error ?? ImageScout.error(withMessage: unableToParseErrorMessage, code: 101)
    operation.terminate(with: completionError)
  }
}

ImageScout Frame