Normally, you can add code snippets for your custom functions into
functions.php which is placed in your theme or child theme folder. But in case you select “mu-plugins” (ip-location-block-mu.php) as “Validation timing” in “Validation rule settings” section, your code for this plugin in
functions.php would be failed to work as you expected.
This restriction is originated from the excution order described in Action Reference where you can find
muplugins_loaded action hook is triggered far before
after_setup_theme which is the timing of your
functions.php to be parsed.
Then what’t the solution?
Installing “drop-in.php” and "drop-in-admin.php"
To install, upload
You can find a sample for
/wp-content/plugins/ip-location-block/wp-content/drop-in-sample.php. Just rename it to dropi-in.php and upload in the directory mentioned above.
drop-in-admin.php are similar but are fired on different sides. The first is used on the front-end and the second is used on the admin side.
Note that even in the case of multisite,
drop-in-admin.php will be called on every site. So if you want each site to behave differently, you should add some code like follows:
functions.phpdoesn't need to be put together into
drop-in.phpbut functions related to only this plugin such as Filter hooks for this plugin.