检索此JSON数据时我出了什么问题？

Question

我觉得这里有示波器问题，但我很茫然。我无法理解如何将数据从json文件传递到javascript对象。

Data.GetJSON = function() {};

Data.GetJSON.prototype = {

  constructor : Data.GetJSON,

  request     : new XMLHttpRequest(),

  // this doesn't seem to be doing what I want
  copy        : function(source, destination) {

    destination = Object.assign({}, source);

    window.alert("Copying " + Object.getOwnPropertyNames(source) + " to " + Object.getOwnPropertyNames(destination));
    window.alert("Copying " + source.toString() + " to " + destination.toString());

                  },

  call        : function(file) {

    "use strict";

    var adventure = this.adventure;
    var copy = this.copy;

    this.request.open('GET', file);

    this.request.responseType = 'json';

    this.request.send();

    // I have a scope problem somewhere in here.
    this.request.onload = function() {

      this.buffer = Object.assign({}, this.response);

      Object.keys(this.buffer).forEach(e => console.log(`key=${e} value=${this.buffer[e]}`));

      copy(this.buffer, adventure);

    };

  }

};

这是使我能够在文本冒险中为玩家更新动作结果的功能。例如，在这种情况下，adventure.id应该返回“ 00”。