google.script.run.withSuccessHandler(function) 不返回数据

Question

我正在使用 G-suite 并使用“google.script.run”功能。我无法从将数据从服务器获取到客户端的函数中获取或设置数据...我可以将数据设置为#myId 的 DOM 并检查，但我想在后台进行...任何想法为什么这不起作用？

function Class(){
  this.data = false;

  this.getData = function(){
    google.script.run.withSuccessHandler(helper).getData();
      function helper(data){
        $('#myId').html('data'); // => works...
        this.data = data; // => does not work...
        return data; // => does not work...
      }
  }

  this.submitData = function(){
    if(this.data === false){
      alert('no data');
    }
    else{
      ...code...
    }
  }

  this.run = function(){
    this.getData();
    this.submitData(); // => always get false;
  }
}

我需要能够使用常规数据设置 this.data...或者至少从 this.getData() 中返回它们

更新

我有

this.getData = function(){
  var testOuput = 'give me test';
    google.script.run.withSuccessHandler(helper).getData();
      function helper(data){
        testOuput = 'give me something else';
      }
  return testOutput;   
}

this.run {
  alert(this.getData());
}

this.run() // => runs on button click

我的输出总是“给我测试”看起来辅助函数无法访问 GLOBAL SCOPE 变量...

Answer 1

问题：

google.script.run 的时差或异步性质：当时，submitData 执行，this.data 是false，因为getData() 尚未完成执行。

                                                 ➚ Server executes `getData()` => Calls `helper(datafromServer)` after execution 
                                               ➚  
`this.run` => `this.getData()` => Server called with `google.script.run` and  returns void immediately 
                                                (Client will not wait for server/async) 
                                               ➘ `this.submitData()` called => `helper()` hasn't finished executing. `this.data` is still false

解决方案：

在调用helper 之后调用this.submitData()。

片段：

  function helper(data){
    $('#myId').html('data'); // => works...
    this.data = data; 
    this.submitData();// => works
  }

参考资料：

• What is a callback function?

• How do I return the response from an asynchronous call?