PHP file outside doc root needs files outside and inside the document root

Question

I have a library of classes, all interrelated.

Some files are inside the document root and some are outside using the <Directory> and Alias features in httpd.conf

Assuming I have 3 files:

webroot.php (Inside the document root)
alias_directory.php (Inside a folder outside the doc root)
alias_directory2.php (Inside a **different** folder outside the doc root)

If alias_directory2.php needs both webroot.php and alias_directory.php, This does not work. (Remember alias_directory.php and alias_directory2.php are not in the same locations)

require_once $_SERVER['DOCUMENT_ROOT'].'/webroot.php'; //(ok)
require_once $_SERVER['DOCUMENT_ROOT'].'/alias_directory.php'; //(not ok)

This does not work because alias_directory.php is not in the doc root.

Similarly

require_once $_SERVER['DOCUMENT_ROOT'].'/webroot.php'; //(ok)
require_once dirname(__FILE__).'/alias_directory.php'; //(not ok)

The problem here is that dirname(__FILE__) will return the path for alias_directory2.php not alias_directory.php.

This works:

require_once $_SERVER['DOCUMENT_ROOT'].'/webroot.php'; //(ok)
require_once '/full/path/to/directory/alias_directory.php'; //(ok)

But is very nasty and is a maintenance nightmare if I decide to move my library to another location.

How do I solve this problem, is seems that I need a way to resolve an Alias folder properly.

Answer 1

Use dirname twice. Once to get the directory of the current file, again to get the parent of that directory, then step back down into the other directory;

require_once dirname( dirname(__FILE__) ) . '/other_dir/alias_directory.php';

Answer 2

PHP will not be able to resolve the location of your alias_directory.php file. You will need to supply the location of the alias_directory.php file yourself. Either as an absolute path, or relative to alias_directory2.php or the DOCUMENT_ROOT

Example:

If your file locations look something like this:
/var/www/webroot.php
/var/otherdir1/alias_directory.php
/var/otherdir2/alias_directory2.php

From alias_directory2.php you can now include alias_directory.php by either:
require_once('/var/otherdir1/alias_directory.php');
or
require_once(dirname(__FILE__).'/../otherdir1/alias_directory.php');
or
require_once($_SERVER['DOCUMENT_ROOT'].'/../otherdir1/alias_directory.php');

To use relative paths, alias_directory.php should be located somewhere close to alias_directory2.php or DOCUMENT_ROOT

Another solution would be to add the folders in question to the include_path, and use require_once('alias_directory.php'); without path specification.