ruby - 如何根据特定定义的兄弟内容获取 sibling 的 child

Question

我需要找到从以下 XML 数据中收集作者和艺术家信息的最佳方法。 comic节点出现多次并包含一本漫画书的数据。

我无法根据他们的工作职能，作家，艺术家等来抓到合适的人。有时每本漫画书都有多个作家和艺术家。我的计划是将每个添加/附加到一个列表。

因此，对于这本漫画书，我需要获取所有作家和艺术家的显示名称，但工作职能(例如作家)是人名的兄弟。

这是我有的，但不起作用:

writer = []
penciler = []
doc.xpath('//comic').each do |main_element|
 main_element.xpath("mainsection/credits/credit/role[@id='dfWriter']").each do |n|
    writer << n.xpath('person/displayname').text
  end
  main_element.xpath("mainsection/credits/credit/role[@id='dfPenciler']").each do |n|
    penciler << n.xpath('person/displayname').text
  end
end

p "Writer(s): ",writer
p "Penciler(s): ",penciler

这是 XML 文件/数据:

<comic>
  <id>3398</id>
  <index>195</index>
  <mainsection>
    <title>Mind Games</title>
    <myrating>0</myrating>
    <myrating>
      <displayname>0</displayname>
      <sortname>0</sortname>
    </myrating>
    <pagecount>32</pagecount>
    <credits>
      <credit>
        <role id="dfWriter">Writer</role>
        <roleid>dfWriter</roleid>
        <person>
          <displayname>Will Pfeifer</displayname>
          <sortname>Pfeifer, Will</sortname>
          <lastname>Pfeifer</lastname>
          <firstname>Will</firstname>
        </person>
      </credit>
      <credit>
        <role id="dfWriter">Writer</role>
        <roleid>dfWriter</roleid>
        <person>
          <displayname>John Byrne</displayname>
          <sortname>Byrne, John</sortname>
          <lastname>Byrne</lastname>
          <firstname>John</firstname>
        </person>
      </credit>
      <credit>
        <role id="dfPenciler">Penciller</role>
        <roleid>dfPenciler</roleid>
        <person>
          <displayname>John Byrne</displayname>
          <sortname>Byrne, John</sortname>
          <lastname>Byrne</lastname>
          <firstname>John</firstname>
        </person>
      </credit>
    </credits>
  </mainsection>
</comic>

我的代码没有给我想要的结果。我找到了“Getting the siblings of a node with Nokogiri”，但我需要迭代并捕获每个 sibling 。

我可以通过 <roleid>dfWriter</roleid> 搜索或 <role id="dfWriter">Writer</role>因为它们是一样的。

我的预期输出是:

Writer(s): Will Pfeifer, John Byrne 
Penciler(s): John Byrne

Answer 1

您可以使用 XPath following-sibling为此目的轴假设目标元素总是位于之后 role :

doc.xpath('//comic').each do |main_element|
 main_element.xpath("mainsection/credits/credit/role[@id='dfWriter']").each do |n|
    writer << n.xpath('following-sibling::person/displayname').text
  end
  main_element.xpath("mainsection/credits/credit/role[@id='dfPenciler']").each do |n|
    penciler << n.xpath('following-sibling::person/displayname').text
  end
end

或者您可以首先遍历 credit 而不是 role :

doc.xpath('//comic').each do |main_element|
 main_element.xpath("mainsection/credits/credit[role/@id='dfWriter']").each do |n|
    writer << n.xpath('person/displayname').text
  end
  main_element.xpath("mainsection/credits/credit[role/@id='dfPenciler']").each do |n|
    penciler << n.xpath('person/displayname').text
  end
end