d3.js - D3 在将 .data() 设置为附加元素时抛出 "Cannot read property ' ownerDocument' of null"

Question

我收到此错误:

Uncaught TypeError: Cannot read property 'ownerDocument' of null

这是来自设置 .data() 的一行到最近由 d3 添加的元素:

const someSet = someSelection.filter('.some:(filter)')

someSet.each((d, i, nodes) => {
  const someElement = d3.select(nodes[i])
  const someChild = someElement.append('g')

  someChild.data(this.data) // <-- This line throws the error
   .enter()
   .append('circle')
   .classed('some-class', true)
})

环顾四周，我能找到的只有 a source saying they had this error when the element in question hadn't yet been added to the page ，但我已确认在抛出此错误时我的元素已添加到页面中。

Answer 1

结果我忘记在将 .data() 添加到嵌套元素之前添加一个新的空选择:

const someSet = someSelection.filter('.some:(filter)')

someSet.each((d, i, nodes) => {
  const someElement = d3.select(nodes[i])
  const someChild = someElement.append('g')

  someChild.selectAll('circle.some-class') // added empty selection here
   .data(this.data)
   .enter()
   .append('circle')
   .classed('some-class', true)
})

如果我执行诸如创建组、存储对组的引用、附加数据并追加，然后尝试将新数据附加到对组的引用 ( <g> ) 而不是选择组的内容)。例如，这将导致此错误:

const someObj = {} // or some class etc
const someSet = someSelection.filter('.some:(filter)')

someSet.each((d, i, nodes) => {
  const someElement = d3.select(nodes[i])
  const someChild = someElement.append('g')
  someObj.someChild = someChild

  someChild.selectAll('circle.some-class') // added empty selection here
   .data(this.data)
   .enter()
   .append('circle')
   .classed('some-class', true)
})

// ...do stuff
someObj.someChild.data(newData)
// Error because someObj.someChild is a D3 element, not a D3 selection

所以，最后应该是:

someObj.someChild.selectAll('circle.some-class').data(newData)

...或者存储的引用应该是数据添加到的选择。