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register_uninstall_hook()

register_uninstall_hook( string $file, callable $callback )

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Sets the uninstallation hook for a plugin.

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

$filestringrequired
Plugin file.
$callbackcallablerequired
The callback to run when the hook is called. Must be a static method or function.

Source

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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UsesDescription
plugin_basename()wp-includes/plugin.php

Gets the basename of a plugin.

_doing_it_wrong()wp-includes/functions.php

Marks something as being incorrectly called.

update_option()wp-includes/option.php

Updates the value of an option that was already added.

get_option()wp-includes/option.php

Retrieves an option value based on an option name.

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Changelog

VersionDescription
2.7.0Introduced.

User Contributed Notes

  1. Skip to note 3 content
    sangeethksin
    You must log in to vote on the helpfulness of this noteVote results for this note: 2You must log in to vote on the helpfulness of this note

    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
}
  2. Skip to note 4 content
    Andrew Mead
    You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note

    Keep in mind that you cannot pass an anonymous function to register_uninstall_hook. It will attempt to serialize the function resulting in the following error:

    PHP Fatal error: Uncaught Exception: Serialization of 'Closure' is not allowed in /redacted/wp-includes/functions.php:625

    There’s a issue about this here: https://core.trac.wordpress.org/ticket/31496

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