PHP: QR code generator

A simple PHP script using the library phpqrcode for the generation of QR codes

Link to the programme:

https://wiki.ostrowski.net.pl/qrcode/

To generate a QR code for the wifi network, simply edit and paste this text into the generator: 

WIFI:T:<encryption>;S:<SSID>;P:<password>;H:<hidden>;;

Explanation:

Example: 

WIFI:T:WPA;S:quest-network;P:pass1234;;

Solution code:

index.php
<?php
require_once './phpqrcode/qrlib.php'; // include the QR library
 
?>
 
<!DOCTYPE html>
<html>
<head>
    <title>Simple QR Code Generator</title>
</head>
<body>
    <h2>QR Code Generator</h2>
    <form method="post">
        Enter text or URL: <input type="text" name="text" required style="width: 400px;">
        <button type="submit">Generate QR Code</button>
    </form>
	<p>if you want wifi qrcode then edit and paste this: <tt>WIFI:T:WPA;S:quest-network;P:pass1234;;</tt></p>
 
    <?php
    if (!empty($_POST['text'])) {
        $text = $_POST['text'];
        $filename = 'qrcode.png';
 
        // Dynamically adjust the size based on the length of the input text
        $dataLength = strlen($text);
        $size = 5; // Default size
 
        if ($dataLength <= 50) {
            $size = 5; // Small amount of data
        } elseif ($dataLength <= 100) {
            $size = 6; // Medium amount of data
        } elseif ($dataLength <= 200) {
            $size = 7; // Larger data
        } elseif ($dataLength <= 300) {
            $size = 8; // Even larger data
        } else {
            $size = 9; // Very large data
        }
 
        // Create the QR code with the calculated size
        QRcode::png($text, $filename, QR_ECLEVEL_L, $size);
 
        echo "<h3>Your QR Code:</h3>";
        echo "<img src='$filename'><br>";
        echo "<a href='$filename' download>Download QR Code</a>";
    }
    ?>
</body>
</html>