Is simpleXML installed?

It should be there by default with php, but it seems to be omitted in some installs (e.g. V7 PHP on ubuntu)

    //Make sure simplexml is installed (it should be there by default with php, but it seems to be omitted in some installs.
    if (!function_exists('simplexml_load_file'))
      die('Server config issue - simpleXML functions are not available.');    //You can install this on ubuntu using: sudo apt-get install php-xml

Read values

For example, this XML file:

<RootElement>
  <MyXmlChildName>1234</MyXmlChildName>
</RootElement>

Reading a value:

  $xml = simplexml_load_file($_SERVER['DOCUMENT_ROOT'] .  "/my_folder/my_file_name.xml");
  if ($xml !== False)   //Was file loaded OK?
  {
    if (isset($xml->MyXmlChildName))        //Check child exisrts
      echo $xml->MyXmlChildName . "<br>";   //Get its value
  }

Read XML to array example

    //OPEN OUR XML FILE AND GET THE EXCHANGE RATES
    $output = array();
    $xml = simplexml_load_file('exchangeRates.xml');
    if ($xml !== False)   //Was file loaded OK?
    {
        foreach ($xml as $key => $value) {
            //echo $key . "-" . $value . "<br>";
            $output[$key] = (string)$value;
        }
    }

Write XML File

    $currentTimestamp = date('Y-m-d H:i:s');


    //Create XML file
    $xml = new SimpleXMLElement('<?xml version="1.0" encoding="utf-8"?><root></root>');
    $xml->addChild('ratesLastUpdated', $currentTimestamp);
    //$xml->asXml('exchangeRates.xml');    //<<This won't format the XML doc nicely with line breaks
    // Save the merged XML to the output file with formatting:
    $dom = new DOMDocument("1.0");
    $dom->preserveWhiteSpace = false;
    $dom->formatOutput = true;
    $dom->loadXML($xml->asXML());
    $dom->save('exchangeRates.xml');