A very simple template rendering mechanism.

run.php

<?php

declare(strict_types=1);

function render(string $templateFilePath, array $args = []): string
{
    if (!file_exists($templateFilePath)) {
        throw new Exception("Template file '$templateFilePath' does not exist.");
    }

    extract($args); // extract associative array items into local scope variables

    ob_start(); // buffer the output, so we can get it into a variable instead of returning it immediately
    include $templateFilePath;
    $renderedTemplate = ob_get_clean();

    if ($renderedTemplate === false) {
        throw new Exception(
            "An error ocurred while rendering template '$templateFilePath' with data: \n" . print_r($args, true) . "\n"
        );
    }

    return $renderedTemplate;
}

$data = [
    'title' => 'Hello world!',
    'content' => 'A very simple template rendering mechanism.',
];

echo render(__DIR__ . '/someTemplate.php', $data);

// Prints out:

//<div>
//  <h2>Hello world!</h2>
//  <p>A very simple template rendering mechanism.</p>
//</div>

someTemplate.php

<div>
    <h2><?php print $title; ?></h2>
    <p><?php print $content; ?></p>
</div>