Introduction:

XML (Extensible Markup Language) is a widely used format for structuring data in a hierarchical manner. It is commonly used for data exchange between systems, configuration files, and many other purposes. In PHP, there are various situations where you may need to convert an array into an XML document, especially when working with APIs, web services, or handling configuration data. In this blog, we will explore two methods to achieve this conversion:

1. Using the SimpleXMLElement class.
2. Using a custom PHP function.

Method 1: Using the SimpleXMLElement Class

The SimpleXMLElement class in PHP is a powerful tool for creating and manipulating XML documents. It provides a straightforward way to create XML elements and attributes from PHP data structures like arrays. Here's a step-by-step guide on how to use this method:

// Sample array
$data = [
    'person' => [
        'name' => 'John Doe',
        'age' => 30,
        'email' => '[email protected]',
    ],
];

// Create a new SimpleXMLElement
$xml = new SimpleXMLElement('<root></root>');

// Function to convert an array to XML
function arrayToXML($data, &$xml) {
    foreach ($data as $key => $value) {
        if (is_array($value)) {
            $subnode = $xml->addChild($key);
            arrayToXML($value, $subnode);
        } else {
            $xml->addChild($key, htmlspecialchars($value));
        }
    }
}

// Call the function to convert the array
arrayToXML($data, $xml);

// Output the XML
echo $xml->asXML();

Output:

<?xml version="1.0"?>
<root>
    <person>
        <name>John Doe</name>
        <age>30</age>
        <email>john@example.com</email>
    </person>
</root>

In this method, we first create a SimpleXMLElement object with an empty root element. Then, we define a recursive function arrayToXML that traverses the array and adds elements and values to the XML structure. If the value is an array, it creates a new child element and recursively processes it. If the value is not an array, it adds it as a text node to the XML element. Finally, we call asXML() to obtain the XML representation as a string and output it.

Method 2: Using a Custom PHP Function

While the SimpleXMLElement class is a robust solution, you can also create a custom PHP function to convert arrays to XML. This method gives you more control over the XML structure and allows for custom formatting. Here's how you can do it:

// Sample array
$data = [
    'person' => [
        'name' => 'John Doe',
        'age' => 30,
        'email' => '[email protected]',
    ],
];

// Function to convert an array to XML
function arrayToXML($data, $xml = null) {
    if ($xml === null) {
        $xml = new SimpleXMLElement('<root></root>');
    }
    
    foreach ($data as $key => $value) {
        if (is_array($value)) {
            arrayToXML($value, $xml->addChild($key));
        } else {
            $xml->addChild($key, htmlspecialchars($value));
        }
    }
    
    return $xml->asXML();
}

// Convert the array to XML
$xmlString = arrayToXML($data);

// Output the XML
echo $xmlString;

Output:

<?xml version="1.0"?>
<root>
    <person>
        <name>John Doe</name>
        <age>30</age>
        <email>john@example.com</email>
    </person>
</root>

In this method, we define a custom arrayToXML function that takes the array and an optional XML object as arguments. If no XML object is provided, it creates a new SimpleXMLElement object with an empty root element. The function then processes the array similarly to the previous method but returns the XML object. This allows you to further manipulate or save the XML document as needed.

Conclusion:

In this blog, we have explored two methods for converting arrays to XML documents in PHP. The first method, using the SimpleXMLElement class, provides a straightforward way to create XML structures from arrays. It is especially useful for simple XML transformations and quick conversions. The second method, using a custom PHP function, gives you more control over the XML structure and allows for custom formatting.