访问嵌套的 XML - 向上

Question

如果给出了Detail ID = "5"，我如何找到Item No = "0002" ？

const Detail_id= "5";

let xRes = xmlDoc.evaluate(`//Item/Details/Detail[@Id="${Detail_id}"]`, 
xmlDoc.documentElement);

我现在如何向上查找Item No = "0002"

<xml>
  <Items>
    <Item No="0001">
      <Details>
        <Detail Id="3">
          <Colors>
            <Color colorName="green" />
            <Color colorName="yellow" />
          </Colors>
        </Detail>
      </Details>
    </Item>
    <Item No="0002">
      <Details>
        <Detail Id="5">
          <Colors>
            <Color colorName="purple" />
            <Color colorName="pink" />
          </Colors>
        </Detail>
        <Detail Id="6">
          <Colors>
            <Color colorName="grey" />
            <Color colorName="orange" />
          </Colors>
        </Detail>
      </Details>
    </Item>
  </Items>
</xml>

下面的代码工作正常。为了向下。下面给出了<Item No="0002"> 的所有详细信息。像 Detail Ids 和 colorNames

const SEARCH_NO = "0002";

let xRes = xmlDoc.evaluate(`//Item[@No="${SEARCH_NO}"]`, xmlDoc.documentElement);
const foundNode = xRes.iterateNext();
if (foundNode) {
  xRes = xmlDoc.evaluate('Details/Detail', foundNode);
  let detailNode;
  while ( !!( detailNode = xRes.iterateNext() ) ) {
    const li = showDetail(detailNode.getAttribute("Id"));
    const colXres = xmlDoc.evaluate('Colors/Color/@colorName', detailNode);
    let colorTextNode;
    while ( !!( colorTextNode = colXres.iterateNext() ) ) {
      showColor(li, colorTextNode.textContent);
    }
  }
}

Answer 1

选择目标Detail 后，不要“向上”，而是通过向其添加谓词来调整您的XPath 以直接选择目标Item。

改变

//Item/Details/Detail[@Id="${Detail_id}"]

至

//Item[@No="${SEARCH_NO}" and Details/Detail/@Id="${Detail_id}"]

或者，如果您不知道SEARCH_NO 并且只想找到目标Detail 的Item 祖先，

//Item[Details/Detail/@Id="${Detail_id}"]

---

来自 cmets：

是的，我需要找到 search_no。

然后

//Item[Details/Detail/@Id="${Detail_id}"]/@No

也可以看看

• Use a predicate rather than the parent:: or ancestor:: axis