Here is php 5.2 code which will convert array of any depth to xml document:

Array
(
    ['total_stud']=> 500
    [0] => Array
        (
            [student] => Array
                (
                    [id] => 1
                    [name] => abc
                    [address] => Array
                        (
                            [city]=>Pune
                            [zip]=>411006
                        )                       
                )
        )
    [1] => Array
        (
            [student] => Array
                (
                    [id] => 2
                    [name] => xyz
                    [address] => Array
                        (
                            [city]=>Mumbai
                            [zip]=>400906
                        )   
                )

        )
)

generated XML would be as:

<?xml version="1.0"?>
<student_info>
    <total_stud>500</total_stud>
    <student>
        <id>1</id>
        <name>abc</name>
        <address>
            <city>Pune</city>
            <zip>411006</zip>
        </address>
    </student>
    <student>
        <id>1</id>
        <name>abc</name>
        <address>
            <city>Mumbai</city>
            <zip>400906</zip>
        </address>
    </student>
</student_info>

PHP snippet

<?php
// function defination to convert array to xml
function array_to_xml( $data, &$xml_data ) {
    foreach( $data as value ) {
        if( is_array($value) ) {
            if( is_numeric($key) ){
                $key = 'item'.$key; //dealing with <0/>..<n/> issues
            }
            $subnode = $xml_data->addChild($key);
            array_to_xml($value, $subnode);
        } else {
            $xml_data->addChild("$key",htmlspecialchars("$value"));
        }
     }
}

// initializing or creating array
$data = array('total_stud' => 500);

// creating object of SimpleXMLElement
$xml_data = new SimpleXMLElement('<?xml version="1.0"?><data></data>');

// function call to convert array to xml
array_to_xml($data,$xml_data);

//saving generated xml file; 
$result = $xml_data->asXML('/file/path/name.xml');

?>

Documentation on SimpleXMLElement::asXML used in this snippet

Its easy with the below package, Just install the package via composer :

https://github.com/spatie/array-to-xml

The implementation will be :

$array= 'invoice' => [
    'date' => date('Y-m-d H:i:s'),
    'due_date' => date('Y-m-d H:i:s'),
    'client' => ['name' => 'John', 'code' => ''],
    'items' => [
        'item' => [
            'name' => 'reg1',
            'description' => 'reg1 on evt',
            'unit_price' => '10',
            'quantity' => '1.0'
        ],
        'item' => [
            'name' => 'reg1',
            'description' => 'reg1 on evt',
            'unit_price' => '10',
            'quantity' => '1.0'
        ]
    ]
]

And then :

$result = ArrayToXml::convert($array);

Don't forget to include use Spatie\ArrayToXml\ArrayToXml; at the top of the class/Controller.

easy!

$xml = simplexml_load_string($xmlstring, "SimpleXMLElement", LIBXML_NOCDATA);
$json = json_encode($xml);
$array = json_decode($json,TRUE);

Assuming that the content of xml is in $xml variable, you can use one of the followings:

return response($xml, 200)->header('Content-Type', 'application/xml');

OR

return response($xml, 200, ['Content-Type' => 'application/xml']);

Almost had it! You simply had to pass the $subnode, not $xml into the recursive call of function:

// XML BUILD RECURSIVE FUNCTION
function array_to_xml($array, &$xml) {        
    foreach($array as $key => $value) {               
        if(is_array($value)) {            
            if(!is_numeric($key)){
                $subnode = $xml->addChild($key);
                array_to_xml($value, $subnode);
            } else {
                array_to_xml($value, $subnode);
            }
        } else {
            $xml->addChild($key, $value);
        }
    }        
}

// EXAMPLE ARRAY
$newArray = array(
                 "Project" =>
                  array("ExternalProjectID" => 53,
                        "ProjectName" => "Doon Creek",
                        "Location" => 
                         array ("Address" => "123 Fake Street",
                                "City" => "Toronto",
                                "Province" => "ON",
                                "Latitude" => 43.0000,
                                "Longitude" => -80.0000),
                        "Website" => 
                        "http://www.website.com/our-communities.php?newcommunity=53",
                        "ContactInformation" => 
                         array("ContactPhone" => "555-5555",
                               "ContactEmail" => "[email protected]",
                               "SalesOfficeAddress" => "123 Fake Street",
                               "SalesOfficeCity" => "Toronto",
                               "SalesOfficeProvince" => "ON")
                       )
                );

// CREATING XML OBJECT
$xml = new SimpleXMLElement('<Projects/>'); 
array_to_xml($newArray, $xml);

// TO PRETTY PRINT OUTPUT
$domxml = new DOMDocument('1.0');
$domxml->preserveWhiteSpace = false;
$domxml->formatOutput = true;
$domxml->loadXML($xml->asXML());

echo $domxml->saveXML();

Output

<?xml version="1.0"?>
<Projects>
  <Project>
    <ExternalProjectID>53</ExternalProjectID>
    <ProjectName>Doon Creek</ProjectName>
    <Location>
      <Address>123 Fake Street</Address>
      <City>Toronto</City>
      <Province>ON</Province>
      <Latitude>43</Latitude>
      <Longitude>-80</Longitude>
    </Location>
    <Website>http://www.website.com/our-communities.php?newcommunity=53</Website>
    <ContactInformation>
      <ContactPhone>555-5555</ContactPhone>
      <ContactEmail>[email protected]</ContactEmail>
      <SalesOfficeAddress>123 Fake Street</SalesOfficeAddress>
      <SalesOfficeCity>Toronto</SalesOfficeCity>
      <SalesOfficeProvince>ON</SalesOfficeProvince>
    </ContactInformation>
  </Project>
</Projects>