What are the key steps involved in transferring data from HTML to XML using PHP?

To transfer data from HTML to XML using PHP, you can use PHP's DOMDocument class to create an XML document and then parse the HTML data to extract the necessary information. This involves loading the HTML data into a DOMDocument object, traversing the DOM tree to extract the desired data, and then creating the corresponding XML structure to store the data.

// Load HTML data into a DOMDocument object
$html = file_get_contents('example.html');
$dom = new DOMDocument();
$dom->loadHTML($html);

// Create a new XML document
$xml = new DOMDocument();
$xml->formatOutput = true;

// Create root element for XML document
$root = $xml->createElement('data');
$xml->appendChild($root);

// Traverse the DOM tree to extract data and create corresponding XML elements
// For example, extract data from HTML table rows and create XML elements
$tableRows = $dom->getElementsByTagName('tr');
foreach ($tableRows as $row) {
    $xmlRow = $xml->createElement('row');
    $root->appendChild($xmlRow);
    
    $cells = $row->getElementsByTagName('td');
    foreach ($cells as $cell) {
        $xmlCell = $xml->createElement('cell', $cell->nodeValue);
        $xmlRow->appendChild($xmlCell);
    }
}

// Save the XML document to a file
$xml->save('output.xml');