递归遍历 SimpleXML 对象结构未知

Question

我在网上找到的每个 xml 迭代示例（包括 PHP 文档、W3School 和堆栈溢出搜索）都假定我们知道结构提前。我想创建一个循环，在每个分支中尽可能深入地迭代，并简单地 returns 它找到的节点名称和值。例如：

<za-lord>
    <orderid>dresden1234</orderid>
    <customer>toot-toot</customer>
    <pizza>
        <sauce>marinara</sauce>
        <crust>thin</crust>
        <toppings>
            <cheese>extra</cheese>
            <veg>
                <onions>yes</onions>
                <peppers>extra</peppers>
                <olives>no</olives>
            </veg>
            <meat>
                <groundbeef>yes</groundbeef>
                <ham>no</ham>
                <sausage>no</sausage>
            </meat>
        </toppings>
    </pizza>
</za-lord>

那么我要找的是：

orderid = dresden1234
customer = toot-toot
sauce = marinara
crust = thin
cheese = extra
onions = yes
peppers = extra
olives = no
groundbeef = yes
ham = no
sausage = no

我现在已经花了几个小时编写代码示例，测试 foreach 的不同变体，简而言之，没有任何东西可以满足我的需求。事先不知道结构，是否可以使用 SimpleXML 递归迭代上面的 xml 和 return 节点名称和值，如果可以，如何？

Answer 1

您可以使用 SimpleXMLIterator 对象并对其进行递归以获取所有节点值：

function list_nodes($sxi) {
    for($sxi->rewind(); $sxi->valid(); $sxi->next() ) {
        if ($sxi->hasChildren()) {
            list_nodes($sxi->current());
        }
        else {
            echo $sxi->key() . " = " . $sxi->current() . "\n";
        }
    }
}
$sxi = new SimpleXMLIterator($xmlstr);
list_nodes($sxi);

输出：

orderid = dresden1234 
customer = toot-toot 
sauce = marinara 
crust = thin 
cheese = extra 
onions = yes 
peppers = extra 
olives = no 
groundbeef = yes 
ham = no 
sausage = no

Demo on 3v4l.org

更新

如果您的 xml 可以有命名空间，您必须采取更复杂的方法，检查文档中每个命名空间中每个节点的子节点：

function list_children($node, $names) {
    $children = false;
    foreach ($names as $name) {
        if (count($node->children($name))) {
            $children = true;
            foreach ($node->children($name) as $child) {
                list_children($child, $names);
            }
        }
    }
    if (!$children) {
        echo $node->getName() . " = $node\n";
    }
}

$xml = new SimpleXMLElement($xmlstr);
list_children($xml, array_merge(array(''), $xml->getNamespaces(true)));

输出（对于演示 xml，与问题相同但添加了名称空间）：

orderid = dresden1234 
customer = toot-toot 
sauce = marinara 
crust = thin 
cheese = extra 
onions = yes 
peppers = extra 
olives = no 
ham = no 
sausage = no
groundbeef = yes

Demo on 3v4l.org

递归遍历 SimpleXML 对象结构未知

Recursively iterating through a SimpleXML object where the structure is not known

php

xml

simplexml

递归遍历 SimpleXML 对象*结构未知*

Recursively iterating through a SimpleXML object *where the structure is not known*

php

xml

simplexml

递归遍历 SimpleXML 对象结构未知

Recursively iterating through a SimpleXML object where the structure is not known