使用XMLReader和PHP获取XML属性

Question

I don't understand why I can't reference the XML Attribute 'headendId'. I've referenced several posts on this and my syntax seems to be fine? Can someone explain what I am doing wrong? Thanks in advance.

<?php
$reader = new XMLReader();
$reader->open('file.xml');

while($reader->read())
{
    if($reader->nodeType == XMLREADER::ELEMENT && $reader->localName == 'headend')
{   
//$reader->read();
$headend = (string)$reader->getAttribute('headendId');
echo $headend;
}
} 

(xml is)

<lineup>
 <headend headendId="something">
  <name>some name</name>
  <ids>ids</ids>
  <codes>codes</codes>
 </headend>
</lineup>

Answer 1

Don't advance to the next node with ->read() once you found it (an attribute is not a node):

while ($reader->read())
{
        if ($reader->nodeType === XMLREADER::ELEMENT 
            && $reader->localName === 'headend')
        {
                echo $reader->getAttribute('headendId');
        }
}

Answer 2

It works similar as outlined last time :

require('xmlreader-iterators.php'); // https://gist.github.com/hakre/5147685

$elements = new XMLElementIterator($reader, 'headend');
foreach ($elements as $element) {
    echo $element->getAttribute('headendId'), "\n";
}

The XMLElementIterator allows to iterate over specific elements only, here you want the headend elements.

Then on each element you can call the getAttribute() method to fetch the string value of the headend headendId attribute.