PHP writing to XML File

Question

I have a problem with writing a specific string to a XML file.

The XML structure is this:

<ePrekrsaji>
<time>
<shift hours="48"/>
</time>
</ePrekrsaji>

The code I use doesnt seem to work:

$my_file = "hours.xml";

$hours = 5

$xml = new DOMDocument();
$xml->load($my_file);
$xml_hours = $xml->createElement($hours);
$nodes = $xml->getElementsByTagName('shift ') ;
if ($nodes->length > 0) {
   $xml->appendChild( $xml_hours );
}
$xml->save($my_file);

ERROR I GET Fatal error: Uncaught exception 'DOMException' with message 'Invalid Character Error' in /var/www/WebDiP/2013_projekti/WebDiP2013_031/skripte/vrijeme.php:17 Stack trace: #0 /var/www/WebDiP/2013_projekti/WebDiP2013_031/skripte/vrijeme.php(17): DOMDocument->createElement('') #1 {main} thrown in /var/www/WebDiP/2013_projekti/WebDiP2013_031/skripte/vrijeme.php on line 17

How to write to this specfic node?

I want the end result to be:

<ePrekrsaji>
    <time>
    <shift hours="5"/>
    </time>
</ePrekrsaji>

Answer 1

You tried to create an element <5 /> , are you sure it's the correct element name?

I think you wanted to make st. like this:

$xml_hours = $xml->createElement('hours', $hours);

Answer 2

I post you a solution with SimpleXML class, so we getting the data from file using file_get_contents then we edit the attribute hours of shift element, then we save the contents with file_put_contents .

$file = "hours.xml";
$xml_data = file_get_contents($file);
$xml = new SimpleXMLElement($xml_data);
$xml->time->shift->attributes()->hours = 5;
file_put_contents($file, $xml->asXML());

Answer 3

Here's a corrected version of your code. You just need to get the first shift element and then set it's attribute.

$file = "hours.xml"; 
$hours = 6;

$xml = new DOMDocument();
$xml->load($file);

// get list of all shift elements
$nodes = $xml->getElementsByTagName('shift');
// get first shift element
$xmlShift = $nodes->item(0);
// set attribute "hours"
$xmlShift->setAttribute("hours", $hours);

$xml->save($file);