register_uninstall_hook( string $file, callable $callback )
Set the uninstallation hook for a plugin.
Description Description
Registers the uninstall hook that will be called when the user clicks on the uninstall link that calls for the plugin to uninstall itself. The link won’t be active unless the plugin hooks into the action.
The plugin should not run arbitrary code outside of functions, when registering the uninstall hook. In order to run using the hook, the plugin will have to be included, which means that any code laying outside of a function will be run during the uninstallation process. The plugin should not hinder the uninstallation process.
If the plugin can not be written without running code within the plugin, then the plugin should create a file named ‘uninstall.php’ in the base plugin folder. This file will be called, if it exists, during the uninstallation process bypassing the uninstall hook. The plugin, when using the ‘uninstall.php’ should always check for the ‘WP_UNINSTALL_PLUGIN’ constant, before executing.
Parameters Parameters
- $file
-
(string) (Required) Plugin file.
- $callback
-
(callable) (Required) The callback to run when the hook is called. Must be a static method or function.
Source Source
File: wp-includes/plugin.php
function register_uninstall_hook( $file, $callback ) {
if ( is_array( $callback ) && is_object( $callback[0] ) ) {
_doing_it_wrong( __FUNCTION__, __( 'Only a static class method or function can be used in an uninstall hook.' ), '3.1.0' );
return;
}
/*
* The option should not be autoloaded, because it is not needed in most
* cases. Emphasis should be put on using the 'uninstall.php' way of
* uninstalling the plugin.
*/
$uninstallable_plugins = (array) get_option( 'uninstall_plugins' );
$plugin_basename = plugin_basename( $file );
if ( ! isset( $uninstallable_plugins[ $plugin_basename ] ) || $uninstallable_plugins[ $plugin_basename ] !== $callback ) {
$uninstallable_plugins[ $plugin_basename ] = $callback;
update_option( 'uninstall_plugins', $uninstallable_plugins );
}
}
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Changelog Changelog
| Version | Description |
|---|---|
| 2.7.0 | Introduced. |
User Contributed Notes User Contributed Notes
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Perform Uninstall hook inside register_activation_hook
function your_prefix_activate(){ register_uninstall_hook( __FILE__, 'your_prefix_uninstall' ); } register_activation_hook( __FILE__, 'your_prefix_activate' ); // And here goes the uninstallation function: function your_prefix_uninstall(){ // codes to perform during unistallation }Feedback
It is very important to only register the uninstall hook once upon activation, because
register_uninstall_hook()writes an option each time it is called. This means your plugin would cause an option to be written on every regular page view of anonymous visitors on your website, which would be bad for performance. See https://core.trac.wordpress.org/ticket/31792 Also make sure that your plugin callsregister_uninstall_hook()only once and with the same value. — By sun —