PHP-调整来自外部php文件的URL链接

Question

Context

Let's say I have the following directory context:

.
├── index.php
├── other.php
├── nav.php
└── subfolder
    └── foo.php

My nav.php contains a simple nav element for every page of my site like

<nav>
    <ul>
        <li><a href="index.php">Main</a></li>
        <li><a href="other.php">Another</a></li>
    </ul>
</nav>

Problem

Now, as my nav php file is meant to be universal, I want to be able to use it on php file that are in subfolders of my website, like foo.php. The problem is, including nav.php in foo.php won't give me the excepted result, as the php code is just copy pasted in foo, the url links being relative, the server won't find the files index.php and other.php.

What I tried

I can't use absolute path with $_SERVER["DOCUMENT_ROOT"], because my website is stored on a university server where every student's website is in a personal folder, with a symbolic link from the actual server root to the student's folder. So, if I try to get the real absolute path, the server try to access it with a symbolic link and don't understand it.

I tried to use a different approach, by calculating the base of the website url (from any folder), and then explicitly asking for a absolute link with the double slash syntax ('//' + base + 'index.php'). The problem of this approach, while it works, is being forced to have each php file defining a global variable storing this base url, or having a single php file with this big definition and include it in any php file.

I find the last solution pretty dirty, hacky, and not reliable in any circumstances. So I'm asking if there is a php-native way of doing this (ie handling relative path when including files).

Answer 1

For anyone looking for a quick fix which can do the job: You can recursively search for your index file and add that depth in the url.

<?php
$level = "";
while (file_exists("..") && !file_exists($level . "index.php")) {
    $level = $level . "../";
}
?>

<nav class="col-3">
    <ul>
        <li><a href="<?php echo $level . 'index.php'; ?>">HOME</a></li>
        <li><a href="<?php echo $level . 'query.php'; ?>">REQUÊTE</a></li>
        <li><a href="<?php echo $level . 'view.php'; ?>">VISUALISATION</a></li>
    </ul>
</nav>

The main benefit of this workaround is that it takes only 3 lines of code and works pretty well if you want to find a file that is at the top of the website hierarchy. But it won't satisfy every need, unfortunately.