Set active link on page using includes - php

Question

I have written some code that will highlight a link in the header based on: class="active". The class is connected to some CSS code to style it.
I am currently adding the class="active" the specified link for each page. However, since I want to move my header into it's own file and include it on each page, I will lose the ability to set the class for each page. I could of course add a variable that will allow me to sort of do the same thing.
What I wish to know is if there is a better and secure way to automatically set the class="active" to the page that I am on. I have seen some posts that suggest using: ($_SERVER['PHP_SELF'] but I have read that it could cause some security issues.
Lastly the main problem that I have is that I need to set two links to
class="active" if I am viewing a page that is in the portfolio list item. For instance, if games.html is currently viewed, both the games and the portfolio page should have the code: class="active".
(All of my .html files are read as .php)
Here is the html code I have so far:
<ul>
<li>Home</li>
<li><a class="active" href="portfolio.html">Portfolio</a>
<ul>
<li><a class="active" href="games.html">Games</a></li>
<li>2D Art</li>
<li>3D Models</li>
<li>Particles</li>
<li>Shaders</li>
<li>Environments</li>
<li>Programming</li>
<li>Substance Designer</li>
<li>Music</li>
</ul>
</li>
<li>About</li>
<li>Contact</li>
<li>Store</li>
</ul>
Any help will be appreciated!

Answer 1

PHP_SELF is safe when you only use it to compare values and don't directly use it in your html:
The portfolio menu can be made active by nested all related pages in a folder called portfolio and checking if the path starts with that folder.
<?php
$currentPage = $_SERVER['PHP_SELF'];
$portfolioFolder = 'portfolio/';
$isPortfolioFolder = substr($currentPage, 0, strlen($portfolioFolder)) == $portfolioFolder);
?>
<ul>
<li>Home</li>
<li><a class="<?= $isPortfolioPage ? 'active' : '' ?>" href="portfolio.html">Portfolio</a>
<ul>
<li>Games</li>
<li>2D Art</li>
<li>3D Models</li>
<li>Particles</li>
<li>Shaders</li>
<li>Environments</li>
<li>Programming</li>
<li>Substance Designer</li>
<li>Music</li>
</ul>
</li>
<li>About</li>
<li>Contact</li>
<li>Store</li>
</ul>