PHP RSS XML 再次解析、过滤和展示

Question

我正在使用DOMDocument. 那很好用。我需要解析我的 XML，找到特定的值，然后只再次显示某些节点。

XML 看起来像这样......

<rss version="2.0">

  <channel>

  <title>Title</title>

  <link></link>

  <item>

    <title>Title #1</title>

    <description>Here I want to filter</description>

  </item>

  <item>

    <title>Title #2</title>

    <description>Should not be displayed</description>

  </item>

</channel>

我想在描述标签内搜索，如果找到关键字我想显示item. 如果找不到，我想删除 parent item。

到目前为止，这就是我尝试过的...

<?php

header('Content-Type: text/xml');

// Load our XML document

$rss = new DOMDocument();

$rss->load('https://myurl');

$description = $rss->getElementsByTagName('description');

foreach ($description as $node) {

    $s = $node->nodeValue;

    if (strpos($s, 'filter') !== false)

    {

      //found the keyword, nothing to delete

    }

    else

    {

      //didnt find it, now delete item

      $node->parentNode->parentNode->removeChild($node->parentNode);

    }

}

echo $description->saveXml();

我正在尝试获取所有描述节点，检查它们是否包含字符串，如果不包含，则删除父节点。搜索字符串有效，但删除节点无效。如果我回显我的 XML，则没有任何改变。

Answer 1

getElementsByTagName()将返回“实时”结果。如果您修改文档，它将发生变化。您可以用来iterator_to_array()制作稳定的副本。另一种选择是使用 Xpath 表达式来获取特定节点。$document = new DOMDocument();$document->loadXML($xmlString);$xpath = new DOMXpath($document);// fetch items that contain "filter" in their description$items = $xpath->evaluate('/rss/channel/item[contains(description, "filter")]');foreach ($items as $item) {&nbsp; &nbsp; // dump the title child element text content&nbsp; &nbsp; var_dump($xpath->evaluate('string(title)', $item));}&nbsp;// fetch items that do not contain "filter" in their description$items = $xpath->evaluate('/rss/channel/item[not(contains(description, "filter"))]');foreach ($items as $item) {&nbsp; &nbsp; // remove item element&nbsp; &nbsp; $item->parentNode->removeChild($item);}&nbsp;echo $document->saveXML();输出：string(8) "Title #1"<?xml version="1.0"?><rss version="2.0">&nbsp; <channel>&nbsp; <title>Title</title>&nbsp; <link/>&nbsp; <item>&nbsp; &nbsp; <title>Title #1</title>&nbsp; &nbsp; <description>Here I want to filter</description>&nbsp; </item></channel></rss>