PHP XML: How To Get The NodeValue by Its Siblings? - php

Question

Example of the xml:
<books>
<book>
<title>Hip Hop Hippo</title>
<released>31-12-9999</released>
</book>
<book>
<title>Bee In A Jar</title>
<released>01-01-0001</released>
</book>
</books>
I want to make a function that return the released date of a book title.
Ex: I want to get released date of the 'Hip Hop Hippo' book.
I know I can use simplexml and write ->book[0]->released. But that's only works when I have a static XML and I know where the ->book[$i]->title that match 'Hip Hop Hippo'. But not in dynamic case. I can't predict every changes, since it came from an API provider. It can be book[1], book[2], and so on.
What should I write in my function?

Answer 1

Check out the xpath functions http://php.net/manual/en/simplexmlelement.xpath.php
You will then be able to write a query like: /books/book[title="Hip Hop Hippo"]
$string = <<<XML
<books>
<book>
<title>Hip Hop Hippo</title>
<released>31-12-9999</released>
</book>
<book>
<title>Hip Hop Hippo</title>
<released>31-12-2000</released>
</book>
<book>
<title>Bee In A Jar</title>
<released>01-01-0001</released>
</book>
</books>
XML;
$xml = new SimpleXMLElement($string);
$result = $xml->xpath('/books/book[title="Hip Hop Hippo"]');
foreach($result as $key=>$node)
{
echo '<li>';
echo $node->title . ' / ' . $node->released;
echo '</li>';
}