In the context of building a Content Management System in PHP, what are some considerations to keep in mind when parsing templates and manipulating strings?

When parsing templates and manipulating strings in a Content Management System built in PHP, it's important to sanitize user input to prevent security vulnerabilities like SQL injection or cross-site scripting attacks. Additionally, consider using PHP's built-in functions like `htmlspecialchars()` to escape special characters in output to prevent XSS attacks. Lastly, use PHP's string manipulation functions like `str_replace()` or `preg_replace()` to efficiently manipulate strings within templates.

// Sanitize user input using htmlspecialchars
$user_input = "<script>alert('XSS attack!');</script>";
$sanitized_input = htmlspecialchars($user_input, ENT_QUOTES, 'UTF-8');

// Replace a string in a template
$template = "Hello, {{name}}!";
$replaced_template = str_replace("{{name}}", "John", $template);

// Use preg_replace for more complex string manipulation
$complex_string = "The quick brown fox jumps over the lazy dog.";
$replaced_string = preg_replace("/brown fox/", "red fox", $complex_string);