在Safari上创建具有声明属性的类不起作用

Question

我有一段代码吼叫，我似乎无法使它在Safari上工作。

class handlePdf {
    url             = null;
    wrapper_element = null;
    pdfDoc          = null;
    pageNum         = 1;
    pageRendering   = false;
    pageNumPending  = null;
    scale           = 0.55;
    canvas          = null;
    ctx             = null;
    pdfjsLib        = null;
    parent          = this;

    constructor(options) {
      this.url = options.url;
      this.wrapper_element = options.wrapper_element;

      this.canvas = document.getElementById(this.wrapper_element),
      this.ctx = this.canvas.getContext('2d');
    }
...

Safari在第一个“=”时给出错误我已经阅读了所有文档并且它似乎是正确的。我被卡住了，任何人都可以指向某个方向吗？

Answer 1

由于类字段声明不是标准，您可以使用babel来转换代码 或者不要使用它们并将你的类重构为：

class handlePdf {
    constructor(options) {
      this.init()
      this.url = options.url;
      this.wrapper_element = options.wrapper_element;

      this.canvas = document.getElementById(this.wrapper_element),
      this.ctx = this.canvas.getContext('2d');
    }

    init() {
      this.url             = null;
      this.wrapper_element = null;
      this.pdfDoc          = null;
      this.pageNum         = 1;
      this.pageRendering   = false;
      this.pageNumPending  = null;
      this.scale           = 0.55;
      this.canvas          = null;
      this.ctx             = null;
      this.pdfjsLib        = null;
      this.parent          = this;
    }
...