注意：使用本例中的代码首先应该导入头文件，代码如下：

import RxSwift

Debugging Operators

该类操作帮助调试 Rx 代码。

debug

打印出所有订阅,事件和处理。

example("debug") {
    let disposeBag = DisposeBag()
    var count = 1

    let sequenceThatErrors = Observable<String>.create { observer in
        observer.onNext("")
        observer.onNext("")
        observer.onNext("")

        if count < 5 {
            observer.onError(Error.Test)
            print("Error encountered")
            count += 1
        }

        observer.onNext("")
        observer.onNext("")
        observer.onNext("")
        observer.onCompleted()

        return NopDisposable.instance
    }

    sequenceThatErrors
        .retry(3)
        .debug()
        .subscribeNext { print($0) }
        .addDisposableTo(disposeBag)
}

Debug Area 输出：
--- debug example ---
2016-06-28 17:40:52.902: playground19.swift:42 (__lldb_expr_19) -> subscribed
2016-06-28 17:40:52.904: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍎)
🍎
2016-06-28 17:40:52.904: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍐)
🍐
2016-06-28 17:40:52.905: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍊)
🍊
Error encountered
2016-06-28 17:40:52.908: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍎)
🍎
2016-06-28 17:40:52.908: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍐)
🍐
2016-06-28 17:40:52.909: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍊)
🍊
Error encountered
2016-06-28 17:40:52.911: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍎)
🍎
2016-06-28 17:40:52.912: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍐)
🍐
2016-06-28 17:40:52.912: playground19.swift:42 (__lldb_expr_19) -> Event Next(🍊)
🍊
Error encountered
2016-06-28 17:40:52.915: playground19.swift:42 (__lldb_expr_19) -> Event Error(Test)
2016-06-28 17:40:52.915: playground19.swift:42 (__lldb_expr_19) -> disposed

RxSwift.resourceCount

提供了所有Rx资源分配的计算量,它在开发过程中对于检测泄漏是非常有用的。

example("RxSwift.resourceCount") {
    print(RxSwift.resourceCount)
    
    let disposeBag = DisposeBag()
    
    print(RxSwift.resourceCount)
    
    let variable = Variable("🍎")
    
    let subscription1 = variable.asObservable().subscribeNext { print($0) }
    
    print(RxSwift.resourceCount)
    
    let subscription2 = variable.asObservable().subscribeNext { print($0) }
    
    print(RxSwift.resourceCount)
    
    subscription1.dispose()
    
    print(RxSwift.resourceCount)
    
    subscription2.dispose()
    
    print(RxSwift.resourceCount)
}
    
print(RxSwift.resourceCount)

Debug Area 输出：
--- RxSwift.resourceCount example ---
0
1
🍎
3
🍎
4
3
2
0

RxSwift.resourceCount在默认情况下不启用,通常不会启用发布构建。下面是展示如何启用它：

Follow these instructions to enable RxSwift.resourceCount in your project:

CocoaPods

1. Add a post_install hook to your Podfile, e.g.:

target 'AppTarget' do
pod 'RxSwift'
end

post_install do |installer|
    installer.pods_project.targets.each do |target|
        if target.name == 'RxSwift'
            target.build_configurations.each do |config|
                if config.name == 'Debug'
                    config.build_settings['OTHER_SWIFT_FLAGS'] ||= ['-D', 'TRACE_RESOURCES']
                end
            end
        end
    end
end

2. Run pod update.
3. Build project (Product → Build).

Carthage

1. Run carthage build --configuration Debug.
2. Build project (Product → Build).