Activation Hooks Generator

The three lifecycle routines, in the order they really run — with the version gate that makes upgrades possible and the uninstall file that keeps the database clean.

The plugin

function prefix

version

min PHP

min WordPress

Version 1.2.0 is stored in acme_version. install() re-runs on plugins_loaded whenever the code is ahead of the stored version.

On activation

PHP and WordPress guard

Deactivates itself with a readable message instead of a fatal error.

Deferred rewrite flush

Flags on activation, flushes on wp_loaded once post types exist.

Schedule cron events

Guarded with wp_next_scheduled so activation cannot double-book.

Version-gated upgrades

Compares the stored version with the constant and re-runs install().

Multisite aware

Loops every site with switch_to_blog on a network activation.

Options and tables to manage

1 option · 1 table · 1 cron

options to seed and delete

custom table (no prefix)

cron hooks to clear

roles to remove

On uninstall

Options, site options and scheduled events go. Custom tables and content are left alone — reversible, and usually the right default.

The main plugin file — register_activation_hook needs __FILE__ to be this file.

<?php
// Generated with WP CodeKit — powered by GrowQuest (https://growquest.io).
/**
 * Plugin Name:       Acme plugin
 * Description:       Lifecycle routines: activation, deactivation and upgrades.
 * Version:           1.2.0
 * Requires PHP:      7.4
 * Requires at least: 6.0
 */

defined( 'ABSPATH' ) || exit;

define( 'ACME_VERSION', '1.2.0' );

/**
 * Fires once when the plugin is activated.
 */
function acme_activate() {
	if ( version_compare( PHP_VERSION, '7.4', '<' ) || version_compare( get_bloginfo( 'version' ), '6.0', '<' ) ) {
		deactivate_plugins( plugin_basename( __FILE__ ) );
		wp_die(
			esc_html__( 'This plugin needs PHP 7.4 and WordPress 6.0 or newer.', 'acme' ),
			'',
			array( 'back_link' => true )
		);
	}

	acme_install();
}

/**
 * Seed everything this plugin needs. Safe to run more than once.
 */
function acme_install() {
	$defaults = array(
		'acme_settings' => array(),
	);

	foreach ( $defaults as $option => $value ) {
		add_option( $option, $value );
	}

	global $wpdb;

	$table   = $wpdb->prefix . 'acme_events';
	$charset = $wpdb->get_charset_collate();

	require_once ABSPATH . 'wp-admin/includes/upgrade.php';

	dbDelta(
		"CREATE TABLE {$table} (
			id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
			created datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
			post_id bigint(20) unsigned NOT NULL DEFAULT 0,
			payload longtext NOT NULL,
			PRIMARY KEY  (id),
			KEY post_id (post_id)
		) {$charset}"
	);

	// Rewrite rules cannot be built here — the post type is not registered yet.
	// Flag it and flush on the next load, once init has run.
	update_option( 'acme_flush_rules', 1 );

	if ( ! wp_next_scheduled( 'acme_sync_products' ) ) {
		wp_schedule_event( strtotime( 'tomorrow 03:00' ), 'daily', 'acme_sync_products' );
	}

	update_option( 'acme_version', ACME_VERSION );
}

/**
 * Fires when the plugin is deactivated — including on every update.
 */
function acme_deactivate() {
	wp_clear_scheduled_hook( 'acme_sync_products' );

	flush_rewrite_rules();

	// Nothing is deleted here. Deactivation happens on every update.
}

/**
 * Run install again when the stored version is behind the code.
 */
function acme_maybe_upgrade() {
	$stored = get_option( 'acme_version', '0' );

	if ( version_compare( $stored, ACME_VERSION, '>=' ) ) {
		return;
	}

	acme_install();
}
add_action( 'plugins_loaded', 'acme_maybe_upgrade' );

/**
 * Flush rewrite rules once, after everything is registered.
 */
function acme_maybe_flush_rules() {
	if ( ! get_option( 'acme_flush_rules' ) ) {
		return;
	}

	delete_option( 'acme_flush_rules' );
	flush_rewrite_rules();
}
add_action( 'wp_loaded', 'acme_maybe_flush_rules' );

register_activation_hook( __FILE__, 'acme_activate' );
register_deactivation_hook( __FILE__, 'acme_deactivate' );

// Deletion is handled by uninstall.php — see the other output mode.