multiple files in wordpress plugin

Question

i'm trying to write a plugin with multi files, i'm sure i did it before without a problem but now i have the problem in the subject.

in the main plugin file i included a file name - ydp-includes.php, inside of ydp-includes.php i included all the files i wanted like this:

<?php
include(dirname( __FILE__ ) .'/1.php');
include(dirname( __FILE__ ) .'/2.php');
include(dirname( __FILE__ ) .'/3.php');
include(dirname( __FILE__ ) .'/4.php');
?>

but i'm getting: Fatal error: Call to undefined function add_action(). The files are includes but for a reason i can't see at the moment wordpress doesn't see them as one plugin package and each wordpress function inside ignored.

is there another best practice way to develop multiple files wordpress plugin ? what i'm doing wrong ?

thanks

Answer 1

This happens only if you call a file per HTTP without loading WordPress. That is something you should never do, because the plugin URL might be another domains where cookies don’t work anymore.

Answer 2

I generally have just one PHP file in the plugin folder, then a sub-folder within which all my required PHP files sit. I use the following code in the main file to automatically include all files found in the inc directory:

foreach ( glob( dirname( __FILE__ ) . '/inc/*.php' ) as $file ) {
    require $file;
}