在d3.js中添加新圆后，无法在圆之间创建链接(Can't create links between circles after appending new circles in d3.js)

 首先需要说的是，我对d3.js完全不熟悉（我使用的是版本4）。 现在我有嵌套的节点对象，并尝试在单击父元素后绘制子元素。 部分工作原理：我可以绘制子节点，但不能绘制从父圆圈到子圆圈的链接。 我有这个错误： 
 
 
 
 错误：遗失：哺乳动物 
 
 
 和 
 
 
 
 TypeError：无法在字符串'mammal'上创建属性'vx' 
 
 
 看起来source创建成功，但第一个链接和其他链接的target中断： 
 
  
 
 我不确定问题出在哪里，所以我创建了一个我现在所有代码的小提琴： https ： //jsfiddle.net/L6c6pxrv/4/ 
 
 @KEKUATAN建议我为links分配新数组，不要推送每个项目。 结果是： https ： //jsfiddle.net/L6c6pxrv/3/ 。 没有错误，但看起来链接仍然不知道源和目标的坐标。 
 
 这是我在圆圈点击之后想要实现的（这里我使用固体数组节点和链接从一开始就定义）： https ： //jsfiddle.net/L6c6pxrv/2/ 
 
 谢谢你的帮助！ 

First need to say, that I'm totally new to d3.js (I'm using version 4). For now I have nested object of nodes and trying to draw child elements after clicking parent. And it works partly: I can draw child nodes, but not links from parent circle to child circles. I've got this errors:
 
 
 
Error: missing: mammal
 
 
and
 
 
 
TypeError: Cannot create property 'vx' on string 'mammal'
 
 
Looks like source created successfully, but target breaks at the first link and others:
 
 
I'm not sure where the issue is, so I have created a fiddle with all code that I have for now: https://jsfiddle.net/L6c6pxrv/4/
 
@KEKUATAN suggested me to assign new array to links, don't push each item. The result is: https://jsfiddle.net/L6c6pxrv/3/. There is no errors anymore, but looks like links still doesn't know coordinates of source and target.
 
Here is what I'm trying to achieve after circle click (here I'm using solid array of nodes and links are defined from the very beginning): https://jsfiddle.net/L6c6pxrv/2/
 
Thanks for any help!

原文：https://stackoverflow.com/questions/46263992