在 XML 中创建子元素

Question

我正在努力完成以下工作：

<?xml version="1.0"?>
<books>
<book>
<name>Harry potter</name>
<category>Adventure | Family | Fantasy</category>
<pages>850</pages>
<author>
<author_name>Jhon Doe</author_name>
<author_wiki>http://wikipedia....</author_wiki>
</author>
<description>lorem ipsum blabla</description>
</book>
</books>

我无法开始工作的部分是介于两者之间的作者元素。 但是我不能再进一步了，我尝试了很多东西，但似乎只给了我空白页。 我现在拥有的：

<?xml version="1.0"?>
<books>
<book>
<name>Harry potter</name>
<category>Adventure | Family | Fantasy</category>
<pages>850</pages>
<description>lorem ipsum blabla</description>
</book>
</books>

<?php header('Content-Type: text/xml;'); 
// Start XML file, create parent node
$doc = new DOMDocument('1.0');
$root = $doc->createElement('books');
$root = $doc->appendChild($root);
// we want a nice output
$doc->formatOutput = true;
$user = $doc->createElement('book');
$user = $doc->appendChild($user);
$title = $doc->createElement('name');
$title = $user->appendChild($title);
$text = $doc->createTextNode('Harry potter');
$text = $title->appendChild($text);
$title = $doc->createElement('category');
$title = $user->appendChild($title);
$text = $doc->createTextNode('Adventure | Family | Fantasy');
$text = $title->appendChild($text);
$title = $doc->createElement('pages');
$title = $user->appendChild($title);
$text = $doc->createTextNode('850');
$text = $title->appendChild($text);
$title = $doc->createElement('description');
$title = $user->appendChild($title);
$text = $doc->createTextNode('lorem ipsum blabla');
$text = $title->appendChild($text);
$user = $root->appendChild($user);
echo $doc->saveXML();
?>

Answer 1

向 DOM 添加节点需要 3 个步骤

1. 使用像createElement()或createTextNode()这样的Document方法创建节点
2. 配置节点并追加子节点
3. 将节点追加到其父节点节点

第 2 步和第 3 步是可互换的。您可以在添加节点之后或之前配置节点。 appendChild() 返回追加节点。

我根据结果 xml 中的级别缩进了调用：

$doc = new DOMDocument('1.0');
$doc->formatOutput = true;

$books = $doc->appendChild($doc->createElement('books'));
  $book = $books->appendChild($doc->createElement('book'));
    $name = $book->appendChild($doc->createElement('name'));
      $name->appendChild($doc->createTextNode('Harry potter'));
    $category = $book->appendChild($doc->createElement('category'));
      $category->appendChild($doc->createTextNode('Adventure | Family | Fantasy'));
    $pages = $book->appendChild($doc->createElement('pages'));
      $pages->appendChild($doc->createTextNode('850'));

    $author = $book->appendChild($doc->createElement('author'));
      $authorName = $author->appendChild($doc->createElement('author_name'));
        $authorName->appendChild($doc->createTextNode('John Doe'));
      $authorWiki = $author->appendChild($doc->createElement('author_wiki'));
        $authorWiki->appendChild($doc->createTextNode('http://wikipedia....'));

    $description = $book->appendChild($doc->createElement('description'));
      $description->appendChild($doc->createTextNode('lorem ipsum blabla'));

echo $doc->saveXML();

Answer 2

您需要在这里做的是将作者详细信息附加到作者元素而不是根元素。所以这样的事情会起作用：

header('Content-Type: text/xml;'); 
$doc = new DOMDocument('1.0');
$doc->formatOutput = true;

$book = $doc->createElement("book");
$doc->appendChild($book);

$author = $doc->createElement("author");
$book->appendChild($author); // add author as child of book

// you can add content at the same time as creating the element
$author_name = $doc->createElement("author_name", "John Doe");
// append author name to author element
$author->appendChild($author_name); 

echo $doc->saveXML();

还请注意，您可以通过在 createElement 中添加文本来节省一些空间来创建文本节点，尽管在某些情况下这可能还不够，因为值没有被转义（参考：php.net - 我只是在这里使用它是为了快速） .

样本输出：

<book>
  <author>
    <author_name>John Doe</author_name>
  </author>
</book>