Question

一旦我解决了承诺，我无法将值传递到范围之外。请在这里查看我的代码。

var FullName;
async.series([
  function(callback) {
    var name = element(by.css('.xyz')).getText().then(function(text) {
      console.log("print name" + text);
      FullName = text;
      console.log("Able to print successfully" + FullName);
    });
    console.log("Unable to print the name outside" + FullName);
    callback();
  },
  function(callback) {
    //I want to retrieve the FullName value to this function. 
    //but unable to bring the value to this function
    console.log("Unable to print the name on the second function too" + FullName)
    callback();
  }

], function(err) {
  done();
})

Answer 1

我已在代码的第一部分添加了注解来解释问题

var FullName;
async.series([
  function(callback) {
    var name = element(by.css('.xyz')).getText().then(function(text) {
      console.log("print name" + text);
      FullName = text;
      console.log("Able to print successfully" + FullName);
    });
    // here, the .then callback hasn't been invoked yet, so FullName is not yet changed
    console.log("Unable to print the name outside" + FullName);
    // and, you're calling callback() before the .then callback is invoked, so, in the next code, FullName is not changed either
    callback();
  },

您可以将其重写为

var FullName;
async.series([
  function(callback) {
    var name = element(by.css('.xyz')).getText().then(function(text) {
      console.log("print name" + text);
      FullName = text;
      console.log("Able to print successfully" + FullName);
      callback(); // callback once all asynchronous ops are done
    });
  },
  function(callback) {
    console.log("Now able to print the name on the second function " + FullName)
    callback();
  }

], function(err) {
  done();
})

或者，简单地说，没有async.js，因为Promises + async.js从来都不是一个好的组合，你的代码相当于

element(by.css('.xyz')).getText()
.then(function(FullName) {
    // do wahtever you need to with FullName in here, note it's NOT global
});

如何访问范围之外的promise所解决的值

1 个答案: