Remove .htaccess portion upon plugin deactivation?

Question

I have a plugin that inserts some rewrite rule in the .htaccess file. However, upon deactivating it, doesn't remove said rule. The rule is nested in # BEGIN My plugin and # END My plugin.

I want to create an uninstall.php file for this plugin to remove the rule created on acrivation.

I've never done this before. I suppose I can get the .htaccess with

$htaccess = dirname(__FILE__) . '/../../../.htaccess';

should I use a regex or is there a proper way to remove a specific rule from the .htaccess?

Answer 1

How do you add your rewrite rule?

If you are adding it manually (opening the .htaccess and adding the lines by yourself in php) then you are also supposed to remove it manually. As you suggested the best way would then be to use regex.

If the rewrite rule was added through the Wordpress API using add_rewrite_rule() you are able to remove it using flush_rewrite_rules(). You could use it like this:

register_activation_hook( __FILE__, 'myplugin_activate' );

function myplugin_deactivate() {
   global $wp_rewrite;
   unset($wp_rewrite->non_wp_rules['the-string-you-passed-as-param-to-add-rewrite-rule']);
   flush_rewrite_rules();
}
register_deactivation_hook( __FILE__, 'myplugin_deactivate' );

Answer 2

With the way the plugin uninstall process works, this kind of things can not be done as you will need to get credentials to be able to write to the .htaccess before performing the uninstall itself, and you can't break the uninstall process into stages. This kind of functionality can be achieved only when the plugin is still active.