As more and more plugins are relying on Zen Cart notifiers to perform their customizations, it can be a developer's debug nightmare when multiple observers are "watching" for the same event, but one is not "playing well with others". It can be a royal-pain to determine who's making those variable changes.
This simple script loads, presumably, at the very end of the site's auto-loaders and generates a report indicating what event(s) are being observed.
Here's a sample of the output:
Class (emp_order_observer) is watching for NOTIFY_ORDER_DURING_CREATE_ADDED_ORDER_COMMENT.
Class (emp_order_observer) is watching for NOTIFY_PROCESS_3RD_PARTY_LOGINS.Note: This is a developer tool, not a "proper" plugin. There's no language file, no means (although it's open source) to create an entry in the admin's menu.
Installation is simple (there are only two files):
Just copy those two files to your Zen Cart storefront and, for each page-load, a file named watching_observers_{page_base}_YYYYMMDD_HHIISS.log is created in the site's /logs sub-directory.
To disable the functionality, either remove those two files or just rename the config.watching_observers.php to have a different file extension, e.g. .php~. To re-enable the functionality, just rename that file's extension back to .php.
You can also limit the output to your IP address. Either directly edit init_watching_observers.php:
if (!defined('WATCHING_OBSERVERS_IP')) define('WATCHING_OBSERVERS_IP', '');… changing the empty string to your IP address or create a file in the store's /includes/extra_datafiles sub-directory that contains that definition's override.