Logger example

This example shows how to create a simple logger that will log 404-errors on your website.

The logger is split into two parts:

• Part 1 loads and registers the logger. The code for this can be placed in yourfunctions.php-file or in a custom plugin.
• Part 2 is the actual logger class, that will live in it’s own file.

Part 1: Loading and registering the logger

Put this code in functions.php or similar.

<?php

/**
 * Use function "register_logger" to load our logger and to
 * notify Simple History that our custom logger exists.
 */
add_action(
	'simple_history/add_custom_logger',
	function ( $simple_history ) {
        require_once __DIR__ . '/class-four-oh-four-logger.php';
		$simple_history->register_logger( 'Four_Oh_Four_Logger' );
	}
);
Code language: HTML, XML (xml)

Part 2: The logger class

Put this code into file class-four-oh-four-logger.php.

<?php

/**
 * This is the class that does the main work!
 */
class Four_Oh_Four_Logger extends \Simple_History\Loggers\Logger {
	/**
	 * The slug is used to identify this logger in various places.
	 */
	public $slug = 'Four_Oh_Four_Logger';

	/**
	 * Return information about this logger.
	 * 
	 * Used to show info about the logger at various places.
	 */
	public function get_info() {
		return array(
			'name'        => __( '404 Logger', 'simple-history' ),
			'description' => __( 'Logs access to pages that result in page not found errors (error code 404)', 'simple-history' ),
			'capability'  => 'edit_pages',
			'messages'    => array(
				'page_not_found' => __( 'Got a 404-page when trying to visit "{request_uri}"', 'simple-history' ),
			),
			'labels'      => array(
				'search' => array(
					'label'   => _x( 'Pages not found (404 errors)', 'User logger: 404', 'simple-history' ),
					'options' => array(
						_x( 'Pages not found', 'User logger: 404', 'simple-history' ) => array(
							'page_not_found',
						),
					),
				), // end search
			), // end labels
		);
	}

	/**
	 * When Simple History has loaded this logger it automagically
	 * calls a loaded() function. This is where you add your actions
	 * and other logger functionality.
	 */
	public function loaded() {
		// Call a function when WordPress finds a 404 page
		add_action( '404_template', array( $this, 'on_404_template' ), 10, 1 );
	}

	/**
	 * Function that is called when WordPress finds a 404 page.
	 * It collects some info and then it logs a warning message
	 * to the log.
	 */
	public function on_404_template( $template ) {
		$context = array(
			'_initiator' => \Simple_History\Log_Initiators::WEB_USER,
			'request_uri' => isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '',
			'http_referer' => isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : '',
		);

		$this->warning_message( 'page_not_found', $context );

		return $template;
	}
}Code language: HTML, XML (xml)