Plugin Log: Log all plugin (de)activations.

t5-plugin-log.php

<?php # -*- coding: utf-8 -*-
/**
 * Plugin Name: T5 Plugin Log
 * Description: Log all plugin (de)activations.
 * Version:     2012.05.27
 * Author:      Thomas Scholz <info@toscho.de>
 * Author URI:  http://toscho.de
 * License:     MIT
 * License URI: http://www.opensource.org/licenses/mit-license.php
 *
 * Copyright (c) 2012 Thomas Scholz
 */

add_action( 'activated_plugin', 't5_plugin_logger', 10, 2 );
add_action( 'deactivated_plugin', 't5_plugin_logger', 10, 2 );
add_action( 'wp_dashboard_setup', 't5_register_plugin_log_dashboard_widget' );

register_deactivation_hook( __FILE__, 't5_deactivate_plugin_log' );

/**
 * Log plugin activations and deactivations.
 *
 * @param  string $plugin
 * @param  bool   $network_wide
 * @return void
 */
function t5_plugin_logger( $plugin, $network_wide )
{
	$log_size = 20;
	$log      = get_option( 't5_plugin_log' );
	! $log && $log = array ();

	// Remove the oldest entry.
	sizeof( $log ) > $log_size and array_shift( $log );

	$plugin_data = get_plugin_data( WP_PLUGIN_DIR . '/' . $plugin );
	$date_format = get_option( 'date_format' ) . ' · ' . get_option( 'time_format' );

	$log[] = array (
		'user'    => esc_html( wp_get_current_user()->display_name ),
		'plugin'  => $plugin_data['Name'],
		'network' => $network_wide ? '✔' : '',
		'time'    => date( $date_format, time() ),
		'action'  => 'deactivated_plugin' === current_filter() ? 'deactivated' : 'activated'
	);

	update_option( 't5_plugin_log', $log );
}

/**
 * Register dashboard widget.
 *
 * @return void
 */
function t5_register_plugin_log_dashboard_widget()
{
	if ( current_user_can( 'activate_plugins' ) )
	{
		wp_add_dashboard_widget(
			't5_plugin_log_dbw',
			'Plugin Log',
			't5_display_plugin_log_dbw'
		);
	}
}

/**
 * Print the dashboard widget.
 *
 * @return void
 */
function t5_display_plugin_log_dbw()
{
	$log = get_option( 't5_plugin_log' );

	if ( ! $log )
	{
		print 'The plugin log is empty';
		return;
	}

	print '<table class="widefat">
	<thead>
		<tr>
			<th>Time</th>
			<th>User</th>
			<th>Action</th>
			<th>Plugin</th>
			<th>Network</th>
		</tr>
	</thead>
	<tbody>';

	foreach ( $log as $entry )
	{
		printf(
			'<tr><td>%1$s</td><td>%2$s</td><td>%3$s</td><td>%4$s</td><td>%5$s</td></tr>',
			$entry['time'],
			$entry['user'],
			$entry['action'],
			$entry['plugin'],
			$entry['network']
		);
	}
	print '</tbody></table>';
}

/**
 * Remove the option for our log.
 *
 * @return void
 */
function t5_deactivate_plugin_log()
{
	// Otherwise the next line wouldn't work.
	remove_action( 'deactivated_plugin', 't5_plugin_logger' );
	// Clean up the options table.
	delete_option( 't5_plugin_log' );
}