Question

我编写了一个外部函数，该函数接受一个参数并计算某些事件的出现，这些事件以整数形式存储在变量totalNumToAck中。然后，我尝试返回该计算出的整数作为已兑现的承诺，并在以后使用它。我调用该函数并将参数成功传递给它。它做了它需要做的事情，但是我很难返回结果。在我尝试使用的代码中，它始终为0。能否请您指出我做错了什么？

编辑：实际上看起来第二种方法可行，而我的实际问题是由于异步执行而导致的外部函数本身。代码到达这一行：deferred.fulfill（totalNumToAck）; 在for循环之前完成，因此总是返回0。因此，新问题是如何使我的返回等待“ for循环”完成？

我的简化代码如下：

//The function I want to call, which is in a different file:


MyExternalFunction(numOfLines)  {

    var totalNumToAck =0;
    var deferred = protractor.promise.defer();


    for (var i = 0; i < numOfLines; ++i) {  
            //code to analyze the page      
            if (somecondition) {
                totalNumToAck++;
                }

    }
    console.log('found' + totalNumToAck + 'elements');
    deferred.fulfill(totalNumToAck);
    return deferred.promise;

};

//The code where I try to use the function - Edit: this actually works! but the problem is in ext function

myextstuff.MyExternalFunction(5).then(function (totalNumToAck ) {
    console.log ("number returned from ext function: " + totalNumToAck );
    //other code that needs to use integer value that external function returns
});

//Also tried - Edit: this actually works too! but the problem is in ext function
response = myextstuff.MyExternalFunction(5);
response.then(function(cellValue){   
    console.log ("number returned from ext function: " + cellValue);
    totalNumToAck =  cellValue;
    //other code that needs to use integer value that external function returns
        });

Answer 1

您可以尝试以下尝试

# Java 1.8
RUN apt-get install -y software-properties-common && \
    add-apt-repository ppa:webupd8team/java -y && \
    apt-get update && \
    echo oracle-java8-installer shared/accepted-oracle-license-v1-1 select true | /usr/bin/debconf-set-selections && \
    apt-get install -y oracle-java8-installer && \
    apt-get clean

Answer 2

我能够使用for循环解决我的问题。我的外部函数现在看起来像：

MyExternalFunction(numOfLines)  {
    var totalNumToAck =0;
    var deferred = protractor.promise.defer();

    browser.wait(function () {
       return SomeElementThatIKnowIsPresent.isPresent();
    }, 50000).then(function () {
    for (var i = 0; i < numOfLines; ++i) {  
            //code to analyze the page      
            if (somecondition) {
                totalNumToAck++;
                }

    }
    }).then(function () {
        console.log('found' + totalNumToAck + 'elements');
        deferred.fulfill(totalNumToAck);
    });

    return deferred.promise;
};

这确保for循环将结束，然后才推迟。fulfill（totalNumToAck）;将会发生。谢谢您的帮助。

如何从量角器的外部函数返回整数作为承诺？

2 个答案: