Enqueueing common php scripts in a plugin

Question

I have a plugin rejected by wordpress.org, one of the resasons is this:

Unsafe Requiring of Common Libraries Since you're using a common library, it's important that you enqueue it safely. Example(s):

require_once('jsonld.php');

Since that is a common library, you need to detect IF the code is already included and not re-include it, as doing so will cause conflicts if two people call the same defines and functions.

I understand about enqueueing jQuery and CSS - but this is a PHP script with multiple functions.

1. If this script is common do I need to just reference it in the WP Core?
2. Otherwise do I need to just look at the functions I'm calling and wrap them in a class (I'm uncertain about this) or can I refer to the whole php script?
3. What is the standard way of doing this?

Thanks

Dan

Answer 1

1. No, it just means it's used by many plugins, not that Core includes it.
2. Many of the functions in that library seem to use the JsonLdProcessor class that is also in that library, I'd check for that before including:

 

if ( ! class_exists( 'JsonLdProcessor' ) ) {
    require_once( 'jsonld.php' )
}

Answer 2

You can check included files first.

$included_files = get_included_files();

if (!in_array("jsonld.php",$included files)) {

    require_once('jsonld.php');
}