将给定的发布者失败类型设置为“从不合并" [英] Set a given Publishers Failure type to Never in Combine

问题描述

是否可以将给定的 AnyPublisher< AnyType，SomeError> 转换为 AnyPublisher< AnyType，Never> ?

Is there a way to transform a given AnyPublisher<AnyType, SomeError> to AnyPublisher<AnyType, Never>?

推荐答案

以从不作为错误类型的发布者意味着它根本不会抛出错误.它将始终提供价值.

A publisher with Never as error type mean that it can't throw error at all. It will always deliver a value.

要获得一个永远不会抛出错误的发布者，您有两种解决方法:

To obtain a publisher that can never throw errors you have 2 solutions:

1/捕获所有可能的错误:

1/ Catch all possible errors:

let publisher: AnyPublisher<AnyType, SomeError> = //...

publisher.catch { error in
  // handle the error here. The `catch` operator requires to
  // return a "fallback value" as a publisher
  return Just(/* ... */) // as an example
}

2/如果您确定发布者不会抛出任何错误，则可以使用 .assertNoFailure()，它将转换您的发布者.请注意，通过 .assertNoFailure()传递错误时，您的应用将立即崩溃.

2/ If you are sure that there no errors can be thrown by the publisher, you can use .assertNoFailure(), that will convert your publisher. Note that is an error pass through the .assertNoFailure(), your app will crash immediately.

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