PHP的活动导航栏？

I'm trying to make an active navigation bar using PHP where the current page will be highlighted or colored in the navigation bar. The code I used:

<ul class="topmenu">
  <li <?php if($_GET['page']="home") { ?> class="active" <?php } ?>>
    <a href="home.php"><b>Bienvenue</b></a>
  </li>
  <li <?php if($_GET['page']="livres") { ?> class="active" <?php } ?>>
    <a href="livres.php"><b>Livres</b></a>
  </li>
  <li <?php if($_GET['page']="bibliotheque") { ?> class="active" <?php } ?>>
    <a href="bibliotheque.php"><b>Bibliothèque</b></a>
  </li>
  <li <?php if($_GET['page']="universite") { ?> class="active" <?php } ?>>
    <a href="universite.php"><b>L'université</b></a>
  </li>
  <li <?php if($_GET['page']="contact") { ?> class="active" <?php } ?>>
    <a href=""><b>Contact</b></a>
  </li>
</ul>

The code will put the attribut in the class active if the page is the current page in the navigation bar. However, all the attributs will be given the class active in this case. How do I fix this?

P.S: I am not looking for any JS or jQuery alternatives, I'm trying to make this work with PHP only.

You could use $_SERVER['SCRIPT_NAME'].

<ul class="topmenu">
            <li <?php if($_SERVER['SCRIPT_NAME']=="/home.php") { ?>  class="active"   <?php   }  ?>><a href="home.php"><b>Bienvenue</b></a></li>
            <li <?php if($_SERVER['SCRIPT_NAME']=="/livres.php") { ?>  class="active"   <?php   }  ?>><a href="livres.php"><b>Livres</b></a></li>
            <li <?php if($_SERVER['SCRIPT_NAME']=="/bibliotheque.php") { ?>  class="active"   <?php   }  ?>><a href="bibliotheque.php"><b>Bibliothèque</b></a></li>
            <li <?php if($_SERVER['SCRIPT_NAME']=="/universite.php") { ?>  class="active"   <?php   }  ?>><a href="universite.php"><b>L'université</b></a></li>
            <li <?php if($_SERVER['SCRIPT_NAME']=="/contact.php") { ?>  class="active"   <?php   }  ?>><a href="contact.php"><b>Contact</b></a></li>
</ul>

I don't use PHP, but give the current page the active tag, and change it per file. Then a single class definition in the CSS handles changing the color for each page.

HTML:

<nav>
    <a class="active" href="/home/">Home</a>
    <a href="/cal/">Calendar</a>
    <a href="/CC/">Community</a>
</nav>

CSS:

.active {
    background-color: #4CAF50;
}
  1. Declare page variables at the very top of each individual page.
  2. Example: <? $page="home";?>
  3. For each list item in your nav bar add if statment with corresponding variable and active class.
  4. Example: <li class="<?if($page=="home"){?>active<?}?>"><a href="home.php"><b>Bienvenue</b></a></li>

What this does is assign each page a variable. The variable is compared in the if statements in the nav bar to determine which li gets the active class.