Static Classes in PHP4

[Thepsion5]

Hi,
I'm trying to create a Debugging static class that is compatible with PHP4 but I'm having a great degree of difficulty trying to understand how PHP4 handles static variables. Currently, I have several internal functions that access and assign values to a static array i've declared inside my Debugging class like so:

class Debugger
{
static $DebugClassVariables = array();
function register($name)
  {
    $newVariable = '';
    static $DebugClassVariables;
    if (!is_array($DebugClassVariables))
      $DebugClassVariables = array();
    $DebugClassVariables[$name] = $newVariable;
  }

  function set($name, $value)
  {
    static $DebugClassVariables;
    if (!is_array($DebugClassVariables))
      $DebugClassVariables = array();
    $DebugClassVariables[$name] = $value;
  }
}

I have a function called initialize() that performs all the needed register() and set() calls:

  function initialize()
  {
    Debugger::register('DebugArray');
    Debugger::register('Symbols');
    Debugger::register('IndentSymbols');
    Debugger::register('UnIndentSymbols');
    Debugger::register('CurrentIndent');
    Debugger::register('IndentPerSymbol');
    Debugger::register('Indent');
    Debugger::set('Indent', ' ');
    Debugger::set('IndentPerSymbol', 4);
    Debugger::set('CurrentIndent', 0);
  }

Now here is the behavior that i'm not understanding; Successive calls to the register function result in these respective values for the $DebugVariablesArray:

Array ( [DebugArray] => Array ( ) )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) [IndentSymbols] => Array ( ) )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) [IndentSymbols] => Array ( ) [UnIndentSymbols] => Array ( ) )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) [IndentSymbols] => Array ( ) [UnIndentSymbols] => Array ( ) [CurrentIndent] => )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) [IndentSymbols] => Array ( ) [UnIndentSymbols] => Array ( ) [CurrentIndent] => [IndentPerSymbol] => )
Array ( [DebugArray] => Array ( ) [Symbols] => Array ( ) [IndentSymbols] => Array ( ) [UnIndentSymbols] => Array ( ) [CurrentIndent] => [IndentPerSymbol] => [Indent] => )

Which Makes sense. But this is what happens to the $DebugVariablesArray whenever the three calls to the set() function are made:

Array ( [Indent] => )
Array ( [Indent] => [IndentPerSymbol] => 4 )
Array ( [Indent] => [IndentPerSymbol] => 4 [CurrentIndent] => 0 )

Functions called after this point that attempt to modify or use the $DebugVariablesArray can't find it at all - calling var_dump() on it just print NULL. I can't seem to figure out what's going on here. Any assistance?

[jdorsch]

You are declaring a static class variable which doesn't work in php 4, then also calling static method variables, which are scoped within their own methods.

class foo
{

  function taco( $topping )
  {
      static $toppings ;
      $toppings[] =$topping ;
  }

  function burrito( $topping )
  {
      // This is not the same as the other $toppings
      static $toppings ;
      $toppings[] = $topping ;
  }
}

In the above, $toppings is two completely separate variables, you have the same setup.

Unfortunately php 4 does not natively support static class variables, so you need to fudge it, I think this will work but you might need to change it a bit. If you want to use somewhat better classes (i.e. don't totally suck) upgrade to php 5 if possible.

class foo
{

  function &toppings()
  {
     static $toppings = array() ;
     return $toppings ;
  }  

  function taco( $topping )
  {
     $toppings = &foo::toppings() ;
      $toppings[] =$topping ;
  }

  function burrito( $topping )
  {
      $toppings = &foo::toppings() ;
      $toppings[] = $topping ;
  }
}