Active current page using php not working - php

Question

I have this code in header.php:
<?php
$page = "";
?>
<ul class="nav navbar-nav navbar-right nav-pos">
<li <?php if ($page == "home") { ?> class="active"<?php } ?>>Home</li>
<li <?php if($page == 'about') { ?> class="active"<?php } ?>>About us</li>
<li <?php if($page == 'contact'){ ?> class="active"<?php } ?>>Contact us</li>
<li class="hidden-xs"><i class="fa fa-search fa-rotate-90"></i></li>
</ul>
and on every page i put this code(and the name change depends on current page):
<?php include 'header.php';
$page = 'about' ?>
and in css i made this:
.active{color:red }
But it is not working... any idea why?
Thank you for time, I really appreciate it

Answer 1

The problem is that in your header.php you explicitly set $page = "" - which means none of the checks for $page == 'about'(etc) are passing.
Although you do set $page = 'about' in your main script, this is after the code in header.php has run, and its html output produced.
The solution is simple:
1) remove the $page = "" from header.php
2) set $page = "about" (or equivalent) before the include

Answer 2

You can do by using jQuery just adding this script in the footer section.
$(document).ready(function() {
// get current URL path and assign 'active' class
var pathname = window.location.pathname;
$('.nav > li > a[href="'+pathname+'"]').parent().addClass('active');
});
In your case, this will work.
$(function(){
var current = location.pathname;
$('.nav li a').each(function(){
var $this = $(this);
// if the current path is like this link, make it active
if($this.attr('href').indexOf(current) !== -1){
$this.addClass('active');
}
})
});

Answer 3

first you should remove $page = ""; from header
<?php
$page = "";//remove this line in header file
?>
<ul class="nav navbar-nav navbar-right nav-pos">
Second in every page swap these two lines
<?php
$page = 'about';//swap these lines
include 'header.php' ;
?>
some details: when header load then $page is empty and your conditions false in li tag. so, before header load you should assign value to $page
the best way: you should used $_SERVER['REQUEST_URI'] instead of hard coded $page. Example:
$url= explode('/',$_SERVER['REQUEST_URI']);
$page = end($request_array);//this show your_page.php
$page=preg_replace('"\.php$"', '', $page )//this will remove .php extension