嵌套 xml - 检索满足条件的所有 itemNos答案

【问题标题】：Nested xml - retrieve all itemNos that satisfies condition嵌套 xml - 检索满足条件的所有 itemNos
【发布时间】：2022-11-29 20:17:22
【问题描述】：

我要返回所有满足条件的itemNos No。但是我的代码只返回第一个 itemNo（其 Detail Id="3"）而不返回其余的。

下面仅返回“0001”。我如何让它同时返回“0001”和“0002”，因为两者的 ID = 3。

XML 结构：

<!-- language: lang-xml -->

<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="3">
          <Colors>
            <Color colorName="purple" />
            <Color colorName="pink" />
          </Colors>
        </Detail>
        <Detail Id="6">
          <Colors>
            <Color colorName="grey" />
            <Color colorName="orange" />
          </Colors>
        </Detail>
      </Details>
    </Item>

    <Item No="0003">
      <Details>
        <Detail Id="8">
          <Colors>
            <Color colorName="red" />
          </Colors>
        </Detail>
      </Details>
    </Item>

  </Items>
</xml>

const search_id = "3"

const foundNo = []

let ans= xmlDoc.evaluate(`//Item[Details/Detail/@Id="${search_id}"]/@No`, xmlDoc.documentElement);
        const foundNode = ans.iterateNext();
        foundNo = foundNode.textContent // this returns Item No "0001"

我如何让它同时返回“0001”和“0002”。当前仅返回“0001”。谢谢你。

【问题讨论】：

标签： javascript xml xpath

【解决方案1】：

使用基于浏览器的 XPath API，您需要迭代并收集结果：

const xml = `<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="3">
          <Colors>
            <Color colorName="purple" />
            <Color colorName="pink" />
          </Colors>
        </Detail>
        <Detail Id="6">
          <Colors>
            <Color colorName="grey" />
            <Color colorName="orange" />
          </Colors>
        </Detail>
      </Details>
    </Item>

    <Item No="0003">
      <Details>
        <Detail Id="8">
          <Colors>
            <Color colorName="red" />
          </Colors>
        </Detail>
      </Details>
    </Item>

  </Items>
</xml>`;

const xmlDoc = new DOMParser().parseFromString(xml, 'application/xml');

const search_id = "3";

const foundNos = [];

const ans = xmlDoc.evaluate(`//Item[Details/Detail/@Id="${search_id}"]/@No`, xmlDoc);

var foundNode;
while ((foundNode = ans.iterateNext()) != null)
  foundNos.push(foundNode.textContent);
  
console.log(foundNos);

我建议切换到基于 SaxonJS 的 XPath 3.1，这样可以更容易地使用一个 XPath 表达式收集数据并将其作为一个 JS 数组返回：

const xml = `<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="3">
          <Colors>
            <Color colorName="purple" />
            <Color colorName="pink" />
          </Colors>
        </Detail>
        <Detail Id="6">
          <Colors>
            <Color colorName="grey" />
            <Color colorName="orange" />
          </Colors>
        </Detail>
      </Details>
    </Item>

    <Item No="0003">
      <Details>
        <Detail Id="8">
          <Colors>
            <Color colorName="red" />
          </Colors>
        </Detail>
      </Details>
    </Item>

  </Items>
</xml>`;

const xmlDoc = new DOMParser().parseFromString(xml, 'application/xml');

const search_id = 3;

const foundNos = SaxonJS.XPath.evaluate(`//Item[Details/Detail/@Id = $search_id]/@No/string()`, xmlDoc, { params : { search_id : search_id } });

console.log(foundNos);

&lt;script src="https://martin-honnen.github.io/Saxon-JS-2.5/SaxonJS2.js"&gt;&lt;/script&gt;

SaxonJS 是 Saxonica 的产品，您可以下载它 here 并阅读它的文档 here。

【讨论】：