用php和xpath解析xml - 获取路径right

Question

我想用php SimpleXML和xpath解析XML文件，并且遇到问题，获取路径并访问属性值。任何帮助赞赏。

这里是我的xml文件： -

<message:MessageGroup xmlns="http://mynamespace.com"> 
<Book> 
<BookKey> 
<Value concept="TITLE" value="Gone Girl"/> 
<Value concept="AUTHOR" value="Gillian Flynn"/> 
</BookKey> 
<Sales> 
<Month>Jan</Month> 
<Number value="20"/> 
</Sales> 
<Sales> 
<Month>Feb</Month> 
<Number value="15"/> 
</Sales> 
<Sales> 
<Month>Mar</Month> 
<Number value="30"/> 
</Sales> 
</Book> 
<Book> 
<BookKey> 
<Value concept="TITLE" value="Inferno"/> 
<Value concept="AUTHOR" value="Dan Brown"/> 
</BookKey> 
<Sales> 
<Month>Jan</Month> 
<Number value="10"/> 
</Sales> 
<Sales> 
<Month>Feb</Month> 
<Number value="15"/> 
</Sales> 
<Sales> 
<Month>Mar</Month> 
<Number value="3"/> 
</Sales> 
</Book> 
</message:MessageGroup> 

我需要解析此得到以下的输出： -

Gone Girl,Gillian Flynn,Jan,20 
Gone Girl,Gillian Flynn,Feb,15 
Gone Girl,Gillian Flynn,Mar30 
Inferno,Dan Brown,Jan,10 
Inferno,Dan Brown,Feb,15 
Inferno,Dan Brown,Mar,3 

我写了下面的代码： -

<?php 
$xmlfile = 'Books.xml'; 
$xml = simplexml_load_file($xmlfile); 
$namespace = 'http://mynamespace.com'; 
$xml->registerXPathNamespace('ns',$namespace); 
$books = $xml->xpath('//ns:Book'); 

//loop through each book - 

foreach($books as $book) { 

$values = $xml->xpath('ns:BookKey/Value'); 
$bookkeys= array(); 

//loop through each Book's BookKey Values and push them to array - 

foreach($values as $value){ 
array_push($bookkeys, $value->attributes()->value); 
}  
$sales = $xml->xpath('ns:Sales'); 

//loop through each Book's Sales and write out Month and Number value after the book key values - 

foreach($sales as $sale){ 
foreach($bookkeys as $bk){ 
echo $bk.","; 
} 
echo $sale->Month; 
echo ","; 
echo $sale->Number->attributes()->value; 
echo "\n"; 
} 
} 
?> 

从var_dump中，$ books数组看起来没问题;尽管$ values和$ sales是空数组，但显然路径并不正确。我已经尝试删除名称空间，但仍然得到一个空数组;我想避免将文件中的所有值和销售情况拉出来，而不是仅仅针对每本特定的书。

Answer 1

您缺少前缀message的名称空间定义。

要从Value获得value，message:MessageGroup/ns:BookKey/ns:Value/@value将是要使用的XPath。