A WordPress plugin that suppresses warnings created by various plugins and themes in WordPress.

suppress-log-warnings.php

<?php
/**
 * Plugin Name: Suppress Log Warnings
 * Plugin URI: https://gist.github.com/christianwach/7d2bb481f9efe185f2b8
 * Description: Suppresses annoying warnings generated by various plugins.
 * Version: 1.0
 *
 * Put this plugin in /wp-content/mu-plugins/
 *
 * @package CMW_Suppress_Log_Warnings
 */

// Exit if accessed directly.
defined( 'ABSPATH' ) || exit;

/**
 * Suppress Warnings Class.
 *
 * A class that holds plugin functionality.
 *
 * @since 1.0
 */
class CMW_Suppress_Log_Warnings {

	/**
	 * Constructor.
	 *
	 * @since 1.0
	 */
	public function __construct() {

		// Selectively suppress warnings.
		set_error_handler( [ &$this, 'errors_suppress' ] );

		// Suppress Akismet logging.
		add_filter( 'akismet_debug_log', [ $this, 'akismet_suppress' ] );

		// Disable Query Monitor's error handling.
		if ( ! defined( 'QM_DISABLE_ERROR_HANDLER' ) ) {
			define( 'QM_DISABLE_ERROR_HANDLER', true );
		}

	}

	/**
	 * Suppress errors generated by specified plugins.
	 *
	 * @since 1.0
	 *
	 * @param int $errno The error number.
	 * @param string $errstr The error message.
	 * @param string $errfile Path to the file that caused the error.
	 * @return bool True to suppress error reporting; false to use default error handler.
	 */
	public function errors_suppress( $errno, $errstr, $errfile = '' ) {

		// Return true to disable all strict notices.
		if ( E_STRICT == $errno ) {
			//return true;
		}

		// Do not display these notices:
		$patterns = [

			// Annoying CiviCRM Smarty notices.
			'uploads/civicrm/templates_c',
			'files/civicrm/templates_c',

			// Older BuddyPress Group extensions.
			'Group_Extension::display',

			// Annoying BuddyPress notices.
			'bp_setup_current_user was called',
			'bp_setup_current_user wurde', // in German

			// Annoying bbPress notices.
			'bbp_setup_current_user was called',
			'bbp_setup_current_user wurde', // in German

			// Suppress older widget notices. Comment out to debug.
			'The called constructor method for WP_Widget',
			'WP_Widget ist seit Version 4.3.0', // in German

		];

		foreach ( $patterns as $pattern ) {
			$pattern = str_replace( [ '/', '\\' ], DIRECTORY_SEPARATOR, $pattern );
			if ( false !== strpos( $errstr, $pattern ) ) {
				return true;
			}
			if ( false !== strpos( $errfile, $pattern ) ) {
				return true;
			}
		}

		// The path was not found, so report the error.
		return false;

	}

	/**
	 * Suppress debug logging generated by the Akismet plugin.
	 *
	 * @since 1.0
	 *
	 * @return bool True to allow error reporting; false to disallow.
	 */
	public function akismet_suppress() {
		return false;
	}

}

/**
 * Gets a reference to this plugin.
 *
 * @since 1.0
 *
 * @return CMW_Suppress_Log_Warnings $plugin The plugin reference.
 */
function cmw_suppress_log_warnings() {

	// Return instance.
	static $plugin;
	if ( ! isset( $plugin ) ) {
		$plugin = new CMW_Suppress_Log_Warnings();
	}
	return $plugin;

}

// Bootstrap plugin.
cmw_suppress_log_warnings();