I think I found that when I have an errordocument custom error page, include does not always work because the include requires a directory and the page that has the error may be in a different directory.
directory1/directory2/thispagecausesa404error.php
directory1/thispagecausesa404error.php
If I have include includepage.php;
in my errordocument page, then it won't work.
I resolved to adding include_once $_SERVER['DOCUMENT_ROOT'].'/includepage.php';
to the errordocument page, which solves the problem, but I suspect that I am doing something wrong or not seeing the proper way to have a flawless include on an error page.
What am I doing wrong?
I'd recommend never relying on DOCUMENT_ROOT
being set correctly. Instead, use a relative path from the current script via the __DIR__
magic constant, eg
include __DIR__ . '/relative/path/from/this/script/to/includepage.php';
The path can also contain parent directory traversal via ../
if required, eg
include __DIR__ . '/../../some/dir/includepage.php';