PHP DOM XML 到数组的转换

Question

我有一个 xml 文档如下：

<?xml version="1.0" encoding="UTF-8" ?>

<books>

    <book>

        <name>Title One</name>

        <year>2014</year>

        <authors>

            <author>

                <name>Author One</name>

            </author>

        </authors>

    </book>

    <book serie="yes">

        <name>Title Two</name>

        <year>2015</year>

        <authors>

            <author>

                <name>Author two</name>

            </author>

            <author>

                <name>Author three</name>

            </author>

        </authors>

    </book>

    <book serie="no">

        <name>Title Three</name>

        <year>2015</year>

        <authors>

            <author>

                <name>Author four</name>

            </author>

        </authors>

    </book>

</books>

我想将它转换成下面的数组。

array(

    array('Tittle one', 2014, 'Author One'),

    array('Tittle two', 2015, 'Author two, Author three'),

    array('Tittle three', 2015, 'Author four'),

);

我下面的代码无法生成我想要的数组结构：

function arrayRepresentation(){

    $xmldoc = new DOMDocument();

    $xmldoc->load("data/data.xml");

    $parentArray =  array();

    foreach ($xmldoc->getElementsByTagName('book') as $item) {

        $parentArray[] = array_generate($item);

    }

    var_dump($parentArray);

}

function array_generate($item){

    $movieArray = array();

    $childMovieArray = array();

    for ($i = 0; $i < $item->childNodes->length; ++$i) {

        $child = $item->childNodes->item($i);

        if ($child->nodeType == XML_ELEMENT_NODE) {

            if(hasChild($child)){

                $childMovieArray = array_generate($child);

            }

        }

        $movieArray[] = trim($child->nodeValue);

    }

    

    if(!empty($childMovieArray)){

        $movieArray = array_merge($movieArray,$childMovieArray);

    }

    

    return $movieArray;

}

基本上我循环遍历节点来获取 xml 元素值。然后我检查我的节点是否有更多的子节点，如果有，我再次循环它以获取值。我无法推断出一种方法：（i）不会给我一些空数组元素（ii）检查任何子节点并将所有 xml 同级元素放入单个字符串中

Answer 1

PHP DOM 支持 Xpath 表达式来获取特定节点和值。这大大减少了您需要的循环和条件的数量。这是一个演示：// bootstrap the XML document$document = new DOMDocument();$document->loadXML($xml);$xpath = new DOMXpath($document);$data = [];// iterate the node element nodesforeach ($xpath->evaluate('/books/book') as $book) {&nbsp; &nbsp; $authors = array_map(&nbsp; &nbsp; &nbsp; &nbsp;fn ($node) => $node->textContent,&nbsp; &nbsp; &nbsp; &nbsp;// fetch author name nodes as an array&nbsp; &nbsp; &nbsp; &nbsp;iterator_to_array($xpath->evaluate('authors/author/name', $book))&nbsp; &nbsp; );&nbsp; &nbsp; $data[] = [&nbsp; &nbsp; &nbsp; &nbsp; // cast first name element child to string&nbsp; &nbsp; &nbsp; &nbsp; $xpath->evaluate('string(name)', $book),&nbsp; &nbsp; &nbsp; &nbsp; // cast first year element child to string&nbsp; &nbsp; &nbsp; &nbsp; $xpath->evaluate('string(year)', $book),&nbsp; &nbsp; &nbsp; &nbsp; implode(', ', $authors)&nbsp; &nbsp; ];}var_dump($data);