Logging function write_log() for debugging process

helpers-write-log.php

// -----------------------------------------------------------------------------

/**
 * Logging to debug.log in DEBUG_LOG_DIR dir (default is the root site dir)
 *
 * Note: In the wp-config.php:
 *
 * you need define:
 * 0) define( 'DEBUG_LOG', true )
 *
 * you can define:
 * 1) define( 'DEBUG_LOG_DIR', dirname( __FILE__ ) . '/' );
 * 2) define( 'DEBUG_LOG_INVERTED', false);
 * 3) define( 'DEBUG_BACKTRACE', true);
 *
 * Author K
 * Version 2.2.0.0
 */
if ( ! function_exists( 'write_log' ) ) {
  // const
  if ( ! defined( 'DEBUG_LOG' ) ) {
    define( 'DEBUG_LOG', true );
  }
  if ( ! defined( 'DEBUG_LOG_INVERTED' ) ) {
    define( 'DEBUG_LOG_INVERTED', true );
  }
  if ( ! defined( 'DEBUG_BACKTRACE' ) ) {
    define( 'DEBUG_BACKTRACE', true );
  }
  // function
  function write_log( $log = null, $before = '', $after = '', $clear = false ) {
    static $is_first_run = true;
    static $backtrace_last = null;
    if ( defined( 'DEBUG_LOG' ) && true === DEBUG_LOG && ( defined( 'DEBUG_LOG_DIR' ) || defined( 'ABSPATH' ) ) ) {
      // Smart formatting by the delta time in seconds
      //$time_new           = microtime( true );
      //$time_delta         = round( microtime( true ) - $time_new, 3 ) * 1000;
      //$new_pass_separator = ( $time_delta > 3 ) ? ( str_repeat( '-', 80 ) . PHP_EOL ) : '';
      //$time               = $time_new;
      // Destination File
      $debug_log_file = ( ( defined( 'DEBUG_LOG_DIR' ) ) ? DEBUG_LOG_DIR : ABSPATH ) . 'debug.log';
      // Clear debug.log if 'true' or the file is more than 10Mb (10485760 bytes)
      if ( true === $clear || filesize( $debug_log_file ) > 10485760 || ! file_exists( $debug_log_file ) ) {
        file_put_contents( $debug_log_file, '' );
      }
      if ( is_writable( $debug_log_file ) ) {
        // CONTENT
        $content = '';
        $date    = date( 'Y-m-d H:i:s' );
        // Only string can be in the wrapper role
        $before = is_string( $before ) ? $before : '';
        $after  = is_string( $after ) ? $after : '';
        // SEPARATOR
        // Build content ('-' & 'hr' define a separate line before the content)
        $hr_normal     = ( str_repeat( '-', 29 ) . '[' . $date . ']' . str_repeat( '-', 30 ) ) . PHP_EOL;
        $hr_first_time = ( str_repeat( '=', 29 ) . '[' . $date . ']' . str_repeat( '=', 30 ) ) . PHP_EOL;
        $hr            = in_array( $clear, [ '-', 'hr' ], true ) ? $hr_normal : '';
        $hr            = $is_first_run ? $hr_first_time : $hr;
        // BACKTRACE
        // Debug context info. Help: http://php.net/manual/en/function.debug-backtrace.php
        $info = '';
        if ( defined( 'DEBUG_BACKTRACE' ) && true === DEBUG_BACKTRACE ) {
          $backtrace         = debug_backtrace();
          $backtrace_current = $backtrace[1];
          // Separate line only for new context
          if ( $backtrace_last !== $backtrace_current ) {
            $info = '  Context: ';
            $info .= ! empty( $backtrace_current['class'] ) ? $backtrace_current['class'] : '';
            $info .= ! empty( $backtrace_current['object'] ) ? '[' . $backtrace_current['object'] . ']' : '';
            $info .= ! empty( $backtrace_current['type'] ) ? $backtrace_current['type'] : '';
            $info .= ! empty( $backtrace_current['function'] ) ? $backtrace_current['function'] : '';
            $line = ! empty( $backtrace_current['line'] ) ? $backtrace_current['line'] : '';
            $info .= ! empty( $backtrace_current['file'] ) ? ' in ' . pathinfo( $backtrace_current['file'], PATHINFO_BASENAME ) . '[' . $line . ']' . ' in ' . pathinfo( $backtrace_current['file'], PATHINFO_DIRNAME ) . '\\' : '';
            $info .= PHP_EOL;
            $hr   = $is_first_run ? $hr_first_time : $hr_normal;
          }
          $backtrace_last = $backtrace_current;
        }
        $content .= $before . var_export( $log, true ) . $after . PHP_EOL;
        // Write log
        if ( defined( 'DEBUG_LOG_INVERTED' ) && false === DEBUG_LOG_INVERTED ) {
          $content = $hr . $info . '↓ ' . $content;
          file_put_contents( $debug_log_file, $content, FILE_APPEND ); // was (temp): error_log( $content, 3, $debug_log_file );
        } else {
          $content = '↑ ' . $content . $info . $hr . file_get_contents( $debug_log_file );
          file_put_contents( $debug_log_file, $content );
        }
        $is_first_run = false;
      }
    }
  }
}

// -----------------------------------------------------------------------------