What are some best practices for automatically replacing variables in a self-developed template system in PHP?

When automatically replacing variables in a self-developed template system in PHP, it is important to properly sanitize and validate the input to prevent security vulnerabilities such as code injection. One best practice is to use regular expressions to identify and replace variables in the template with the corresponding values. Additionally, consider implementing a caching mechanism to improve performance by storing the parsed templates for reuse.

function parseTemplate($template, $variables) {
    $parsedTemplate = $template;
    
    foreach ($variables as $key => $value) {
        $parsedTemplate = preg_replace('/{{\s*' . $key . '\s*}}/', $value, $parsedTemplate);
    }
    
    return $parsedTemplate;
}

// Example usage
$template = "Hello, {{ name }}! Your email is {{ email }}.";
$variables = [
    'name' => 'John Doe',
    'email' => 'johndoe@example.com'
];

echo parseTemplate($template, $variables);