A singleton is the "enterprise professional scalable business solution" version of a global variable

The following post got removed from the user contributions for the "OOP Patterns" page of the php manual.

anonymous at world4ch dot org

16-Jul-2007 08:37

A singleton is the "enterprise professional scalable business solution" version of a global variable. It'd be a good idea if this were the IOCCC, but since it isn't, it's better to simply say:

global $lol;

It's also faster and more maintainable, and has the same advantages and disadvantages.

Also, I'll advise against all "enterprise object-oriented industry-standard design patterns". Some of these patterns are correct, but their existence is not. Programming is not about copypasta. It's about thinking, abstracting and combinating. If you can't think of these patterns for yourself when you need them — and in the case of needing them, manage to abstract them so that your code doesn't become a copypasta fest, then you shouldn't be programming in the first place.

Furthermore, the existence of software patterns is a proof of the object-oriented model shortcomings. You shouldn't ever need to do any copypasta in your code. If something is done two or more times, you abstract it. And the language should support a way for you to. There's no reason for a "design pattern" to exist more than once, and since they are trivial (they better be trivial to you, if you are programming), you don't need to study them.

The best advice I can give you is that instead of reading "design patterns", you read Structure and Interpretation of Computer Programs (SICP), a book freely available from MIT where you will learn what you need to program properly in any programming language.

update

See also PHP, the Enterprise, and copypasta?

function debug_writeflnh()

/// write sprint-formatted, html-encoded string to STDOUT
/// return INT(0...) number of parsed values (format string not included) | FALSE
function debug_writeflnh() {
  @list($dbbt, $caller) = debug_backtrace();
  if (isset($caller)) {
    $caller = isset($caller['class'])
        ? ($caller['class'] . (isset($caller['type']) ? $caller['type'] : ':::') . $caller['function'])
        : $caller['function'];
  }
  else {
    $caller = '___MAIN';
  }

  echo '<em class="fw-debug">', $caller, '(', $dbbt['line'], '):</em> ';

  $args = & $dbbt['args'];
  $num_args = count($args);
  if (0 === $num_args) {
    echo '<br />', CRLF, CRLF;
    return 0;
  }

  if (1 === $num_args) {
    $format = '%s';
    $first_arg = 0;
  }
  else {
    $format = & $args[0];
    $first_arg = 1;
  }

  if (!is_string($format)) {
    return FALSE;
  }

  // array_key_exists() catches $arg => NULL, which isset() doesn't
  for (
      $pos = 0, $arg = $first_arg;
      (isset($args[$arg]) || array_key_exists($arg, $args)) &&
      preg_match(
          '/([^%]*)(%(?:[0\x20]|\'[^\'])?-?[0-9]*(?:(?:\.[0-9])?f|[bcduosxX]))/S',
          $format, $hits, PREG_OFFSET_CAPTURE, $pos
      );
      $pos = $hits[2][1] + strlen($hits[2][0]), ++$arg
  ) {
    // from format string
    if (isset($hits[1][0][0])) { // !empty()
      echo htmlspecialchars($hits[1][0]);
    }
    // format string template
    if (1 === strpos($hits[2][0], 's')) { // 's' === $hits[2][0][1]
      // a "compound" type is a non-scalar type
      if ($is_compound = (is_array($args[$arg]) || is_object($args[$arg]))) {
        echo CRLF,'<pre class="fw-debug">';
      }
      ob_start();
      //debug_zval_dump($args[$arg]); // shows number of linked references
      var_dump($args[$arg]);

      static $pcre = '/\]=>(\r\n|[\r\n])(\x20\x20)+/S';
      static $prpl = '] => ';
      echo htmlspecialchars(preg_replace($pcre, $prpl, ob_get_clean()));
      if ($is_compound) {
        echo '</pre>', CRLF;
      }
    }
    else {
      echo htmlspecialchars(sprintf($hits[2][0], $args[$arg]));
    }
  }

  if ($pos < strlen($format)) {
    echo htmlspecialchars(substr($format, $pos));
  }
  echo '<br />', CRLF, CRLF;

  // return number of processed argument variables
  return $num_args - $first_arg;
}

Tach und Mahlzeit!

Well, I just needed an OpenID ... ;-)