Passing PHP variables to XML in a .php file

Question

<?php

include "../music/php/logic/core.php";
include "../music/php/logic/settings.php";
include "../music/php/logic/music.php";
$top = "At world's end";


// create doctype
$dom = new DOMDocument("1.0");

header("Content-Type: text/xml");

?>

<music>
<?php $_xml = "<title>".$top."</title>";
echo $_xml; ?>
</music>

I'm using this code to generate a dynamic XML document. The file is saved as PHP. My problem is that I can't echo php variables into the xml. However I can echo "literal" type text. I can't see anything wrong with my approach, it just doesn't work!

I'm pretty new to XML so I've probably missed something glaringly simple.

I've also tried lines like:

<title><?php echo $top; ?></title>

Answer 1

I think it's echo($_xml);

Answer 2

You don't use DOM this way. You use the DOM API to create the entire document:

$doc   = new DOMDocument();
$books = $doc->createElement( "books" );
$doc->appendChild( $books );
// ...

See:

• http://www.ibm.com/developerworks/library/os-xmldomphp/
• http://www.tonymarston.net/php-mysql/dom.html
• http://articles.techrepublic.com.com/5100-10878_11-6141415.html

---

A more verbose example (generating XHTML with DOM)

// Create head element
$head = $document->createElement('head');
$metahttp = $document->createElement('meta');
$metahttp->setAttribute('http-equiv', 'Content-Type');
$metahttp->setAttribute('content', 'text/html; charset=utf-8');
$head->appendChild($metahttp);

See this tutorial on how to use DOM for XHTML. For reuse of code, you can write your own classes extending DOM classes to get configurable components.

---

If you don't want to use DOM or want to use plain text for generating the XML, just approach it like any other template, e.g.

<root>
    <albums>
        <album id="<?php echo $albumId; ?>">
            <title><?php echo $title; ?></title>
            ... other elements ...
        </album>
    </albums>
</root>