Question

是否有Javascript指令可以避免异步回调地狱？类似于＆＃34;如果那么其他＆＃34;我想象一下＆＃34;然后＆＃34;。例如，假设asyncFunc1（cb，errCb）是一个异步函数，在成功时调用cb（），在失败时调用errCb（）。对于asyncFunc2，asyncFunc3等也一样。使用正确的异步指令，我想做类似的事情：

do (asyncFunc1) {

    // error code for failure of asyncFunc1 goes here

} then (asyncFunc2) {

    // error code for failure of asyncFunc2 goes here

} then (asyncFunc3) {

    // error code for failure of asyncFunc3 goes here

} // etc...

var a=Math.abs(-1); // first synchronous code. This, and all the
// following code, is executed at the  same time of
// the "do (asyncFunc1) { } then ... {}" block

当＆＃34; do（asyncFunc1）＆＃34;时，会调用asyncFunc1。执行时，执行括号内的代码时会执行错误执行＆＃34; asyncFunc2＆＃34;被执行。然后，在出现错误时，括号内的代码执行成功＆＃34; asyncFunc3＆＃34;被执行。所有这些都是在＆＃34; var a = Math.abs（-1）;＆＃34;的同时执行的。以及所有连续的代码。

Promise已经接近了，但是，这将更清晰：无需定义新功能，也不需要金字塔形状。

注1：以上示例与：

相同

asyncFunc1(
    function() {

        asyncFunc2(
            function() {

                asyncFunc3(

                    // etc...

                        function() {

                            var a=Math.abs(-1); // first call of a synchronous function here

                        },
                        function() {
                            // error code for failure of asyncFunc3 goes here
                        }
                )

            }, 
            function() {

                // error code for failure of asyncFunc2 goes here
            }
       )

    },
    function() {

        // error code for failure of asyncFunc1 goes here
    }
)

注2：如果asyncFunc1有参数arg1，arg2，......就可以这样做：

do(asyncFunc1, arg1, arg2, ...) { }

Answer 1

那你已经可以用js做什么了：

  Traceback (most recent call last):
      File "t.py", line 5, in <module>
        d = webdriver.Chrome(chrome_options=chop)
      File "/home/t/env/lib/python3.5/site-packages/selenium/webdriver/chrome/webdriver.py", line 68, in __init__
        keep_alive=True)
      File "/home/t/env/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 89, in __init__
        self.start_session(desired_capabilities, browser_profile)
      File "/home/t/env/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 138, in start_session
        'desiredCapabilities': desired_capabilities,
      File "/home/t/env/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py", line 195, in execute
        self.error_handler.check_response(response)
      File "/home/t/env/lib/python3.5/site-packages/selenium/webdriver/remote/errorhandler.py", line 170, in check_response
        raise exception_class(message, screen, stacktrace)
    selenium.common.exceptions.WebDriverException: Message: unknown error: Chrome failed to start: exited abnormally
      (Driver info: chromedriver=2.30.477691 (6ee44a7247c639c0703f291d320bdf05c1531b57),platform=Linux 4.4.0-21-generic x86_64)

请注意，asyncFunc [2,3]必须是 async ...

有没有Javascript指令可以避免异步回调地狱？

1 个答案: