Debugging is essential for WordPress development. This guide shows you how to create a custom write_log() function in WordPress using error_log(). With this, you can log info, warnings, errors, and more to keep track of issues during development.

Custom write_log() Function in WordPress

Use this function to write messages to the error log while developing:

function write_log($message) {
    if (true === WP_DEBUG) {
        if (is_array($message) || is_object($message)) {
            error_log(print_r($message, true));
        } else {
            error_log($message);
        }
    }
}

Function Explained

• WP_DEBUG Enabled: Logging only works when WP_DEBUG is true in wp-config.php.
• Object/Array Support: Converts arrays and objects to readable strings before logging.
• Scalar Logging: Directly logs strings, numbers, and other simple data types.

Example Usage

function my_custom_function() {
    $data = array('foo' => 'bar');
    write_log('Custom debug message');
    write_log($data);
}

Enable Debugging in wp-config.php

define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);

Logs are saved in your server’s error log file. You can customize this in your php.ini.

Tips for Secure Debugging

• Disable debugging in production: WP_DEBUG = false.
• Don’t log sensitive data like passwords or user details.
• Clean up logs regularly to avoid bloat.

Helpful Links

• WordPress error_log()
• WP_DEBUG Guide
• PHP error_log() Docs

This simple technique helps you keep your development workflow smooth and efficient.