What is the correct way to include files inside Encapsulated Plugins?

https://docs.zen-cart.com/dev/plugins/encapsulated_plugins/converting/

**Explicit include or require of storefront files **
TBD

TBD really isn't very helpful...

I've been trying to convert the addons I use to encapsulated for easier management and upgrading.

lots of them have lines like ```
require DIR_WS_CLASSES . 'sitemapxml.php';

I realize in the case of classes it should be using autoloading, but that doesn't solve all the "require" problems and it requires making huge changes that I don't want to deal with to sometimes very complex addons that just need small patches to work encapsulated.

What is the correct way to include files inside Encapsulated Plugins?

While I agree that the TBD isn't very helpful, I've got a bunch of plugins that use DIR_WS_CLASSES and/or DIR_WS_FUNCTIONS to load plugin-specific classes and functions.

If you'd identify where within a plugin you're trying to use that constant and the 'require' is failing that would help me help you.

Note, too, that the in-core support for encapsulated plugins has significant changes in zc210 and later. What version of Zen Cart is in use?

Using zc210

When a plugin uses require what is the path relative to? is it relative to the directory with index.php or the plugin's directory?

In this case, I tried to make SitemapXML encapslicated and get this error when I try to generate

[24-Sep-2025 20:04:01 America/Vancouver] Request URI: /index.php?main_page=sitemapxml&rebuild=yes, IP address: 127.0.0.1, Language id 1
#0 /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php(29): zen_debug_error_handler()
#1 /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php(29): require()
#2 /usr/home/sites/zen21/www/index.php(35): require('/usr/home/sites...')
--> PHP Warning: require(includes/classes/sitemapxml.php): Failed to open stream: No such file or directory in /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php on line 29.


[24-Sep-2025 20:04:01 America/Vancouver] Request URI: /index.php?main_page=sitemapxml&rebuild=yes, IP address: 127.0.0.1
--> PHP Fatal error: Uncaught Error: Failed opening required 'includes/classes/sitemapxml.php' (include_path='.:/usr/local/share/pear') in /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php:29
Stack trace:
#0 /usr/home/sites/zen21/www/index.php(35): require()
#1 {main}
  thrown in /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php on line 29.

[24-Sep-2025 20:04:01 America/Vancouver] Request URI: /index.php?main_page=sitemapxml&rebuild=yes, IP address: 127.0.0.1
--> PHP Fatal error: Uncaught Error: Failed opening required 'includes/classes/sitemapxml.php' (include_path='.:/usr/local/share/pear') in /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php:29
Stack trace:
#0 /usr/home/sites/zen21/www/index.php(35): require()
#1 {main}
  thrown in /usr/home/sites/zen21/www/zc_plugins/sitemapXML/4.0.5/catalog/includes/modules/pages/sitemapxml/header_php.php on line 29.

zc_plugins/sitemapXML/4.0.5/catalog/includes/classes/sitemapxml.php does exist.

The path is relative to the location of the calling script.