Searching inside all uninstall.php
files that I have in my hard-drive, I've found two that had the function is_multisite()
: User Role Editor and Add Code to Head.
Both use a $wpdb
loop. Simplified:
<?php
/**
* Plugin Uninstall Procedure
*/
// Make sure that we are uninstalling
if ( !defined( 'WP_UNINSTALL_PLUGIN' ) )
exit();
// Leave no trail
$option_name = 'plugin_option_name';
if ( !is_multisite() )
{
delete_option( $option_name );
}
else
{
global $wpdb;
$blog_ids = $wpdb->get_col( "SELECT blog_id FROM $wpdb->blogs" );
$original_blog_id = get_current_blog_id();
foreach ( $blog_ids as $blog_id )
{
switch_to_blog( $blog_id );
delete_option( $option_name );
// OR
// delete_site_option( $option_name );
}
switch_to_blog( $original_blog_id );
}
Related Q&A: Uninstall, Activate, Deactivate a plugin: typical features & how-to