Question

我无法从null更改DOMDocument parentNode。我尝试过同时使用appendChild和replaceChild，但没有运气。

我在哪里错了？

   error_reporting(E_ALL);

   function xml_encode($mixed, $DOMDocument=null) {
      if (is_null($DOMDocument)) {
          $DOMDocument =new DOMDocument;
          $DOMDocument->formatOutput = true;
          xml_encode($mixed, $DOMDocument);
          echo $DOMDocument->saveXML();
      } else {
          if (is_array($mixed)) {
              $node = $DOMDocument->createElement('urlset', 'hello');
              $DOMDocument->parentNode->appendChild($node);
          }
      }
  }

  $data = array();

  for ($x = 0; $x <= 10; $x++) {
      $data['urlset'][] = array(
         'loc' => 'http://www.example.com/user',
         'lastmod' => 'YYYY-MM-DD',
         'changefreq' => 'monthly',
         'priority' => 0.5
      );
  }

  header('Content-Type: application/xml');
  echo xml_encode($data);

?>

http://runnable.com/VWhQksAhdIJYEPLj/xml-encode-for-php

Answer 1

由于文档没有父节点，您需要将根节点直接附加到文档，如下所示：

$DOMDocument->appendChild($node);

自DOMDocument扩展DOMNode以来，这是有效的。

Working example：

error_reporting(E_ALL);

function xml_encode($mixed, &$DOMDocument=null) {
    if (is_null($DOMDocument)) {
        $DOMDocument =new DOMDocument;
        $DOMDocument->formatOutput = true;
        xml_encode($mixed, $DOMDocument);
        return $DOMDocument->saveXML();
    } else {
        if (is_array($mixed)) {
            $node = $DOMDocument->createElement('urlset', 'hello');
            $DOMDocument->appendChild($node);
        }
    }   
}

$data = array();
for ($x = 0; $x <= 10; $x++) {
    $data['urlset'][] = array(
       'loc' => 'http://www.example.com/user',
       'lastmod' => 'YYYY-MM-DD',
       'changefreq' => 'monthly',
       'priority' => 0.5 
    );  
}

header('Content-Type: application/xml');
echo xml_encode($data);

顺便说一句，如果您只想序列化一个XML文件，DOM会有点开销。我会使用模板引擎，这意味着将其作为纯文本处理。

Answer 2

这应该有效，当你创建一个新的DOMDocument时，你还没有root元素，所以你可以创建它并将它添加到文档中

//You could add this to the top of xml_encode
if($DOMDocument->parentNode === null) {
   $root = $DOMDocument->createElement('root');
   $root = $DOMDocument->appendChild($root);
}

//Your script working: 
<?php
error_reporting(E_ALL);

function xml_encode($mixed, $DOMDocument=null) {
    if (is_null($DOMDocument)) {
        $DOMDocument =new DOMDocument();
        $DOMDocument->formatOutput = true;

        //add here, but note that in the "else" it isn't sure if the DOMDocument has a root element 
        $root = $DOMDocument->createElement('root');
        $root = $DOMDocument->appendChild($root);
        xml_encode($mixed, $root);

        echo $DOMDocument->saveXML();
    } else {
        if (is_array($mixed)) {
            $node = $DOMDocument->createElement('urlset', 'hello');
            $DOMDocument->parentNode->appendChild($node);
        }
    }
}

我不确定你为什么需要parentNode？你可以做$DOMDocument->appendChild();

DOMDocument无法更改parentNode

2 个答案: