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DavidJCobb
Nervous Wreck (II) Inmate

From: United States
Insane since: Mar 2009

IP logged posted posted 04-09-2009 23:26 Edit Quote

I'm trying to make a code for a game site that will convert strings resembling the following...

code:
*Legend of Zelda: Ocarina of Time
**Index
**Glitches
***Swordless Link
****Poe Link
***Steal the Fishing Rod
**Videos
**Guides
**Secrets
**Cheats


Into an array structure resembling the following:

code:
array(
   'Legend of Zelda: Ocarina of Time'=>
      array(
         'Index'=>array(),
         'Glitches'=>
            array(
               'Swordless Link'=>
                  array(
                     'Poe Link'=>array()
                  ),
               'Steal the Fishing Rod'=>array()
            ),
         'Videos'=>array(),
         'Guides'=>array(),
         'Secrets'=>array(),
         'Cheats'=>array()
      )
);



Now, to do this, I explode the string at each newline ($treeData = explode("\n", $myString)) and use a foreach to loop through the array of lines. I process each line, using them to build another array, $tree. Basically, once that foreach loop ends, $tree reverts back to the value it had before any of the looping happened.

My code:

code:
<pre><?php
function OutputTreeView($treeString,$root=0) {
   $treeData=explode("\n",$treeString); // array of lines
   $tree = array();
   $curs = array();
   $offset = 0; // not important
   if($root) { // FROM HERE TO THE NEXT COMMENT... IS NOT IMPORTANT.
      $line=$treeData[0];
      $offset=strspn($line,'*');
      $level=0;
      $tree[substr($line,$level+$offset)] = array();
      $curs[$level]=substr($line,$level+$offset);
      array_shift($treeData);
   } else {
      $level=0;
      $line='';
      $tree['[root]']=array();
      $curs[$level]='[root]';
   } // FROM HERE TO THE PREVIOUS COMMENT IS NOT IMPORTANT.
   foreach($treeData as $line) {
      $level= strspn($line,'*')-$offset; // use the "*"s at the beginning to determine how nested we are.
      $curs[$level]=substr($line,$level+$offset); // used to keep track of where we are in $tree, so that we can build $varString
      $varString = '$tree['; // prepare for variable substitution (the double dollar sign trick)
      for($i=0;$i<=$level;$i++) {
         $varString.="'".$curs[$i]."']";
         if($i<$level) { $varString.='['; }
      }
      $$varString = array(); // the actual variable substitution, used to alter $tree
      // [debug statement removed]
      if($level+1<count($curs)) { // this IF and the WHILE inside of it is only NEEDED for debugging.
         while(count($curs)>$level+1) { array_pop($curs); }
      }
   }
   return $tree;
}

$TREE='*Legend of Zelda: Ocarina of Time'."\n".'**Index'."\n".
'**Glitches'."\n".'***Swordless Link'."\n".'****Poe Link'."\n".
'***Steal the Fishing Rod'."\n".'**Videos'."\n".'**Guides'."\n".
'**Secrets'."\n".'**Cheats';
// The string example I presented above. I woulda used a nowdoc, 
// but PHP was throwing a T_SL error even though there was nothing 
// wrong with the syntax (I Googled the error to figure out the cause, 
// and the cause wasn't present) -- ah, well.

echo OutputTreeView($TREE);
?></pre>



Using a large amount of debug statements (most of which have been removed to shorten the code), I am able to tell that $tree is modified during the loop, but these modifications don't "stick" at the end of the loop. Now, $tree isn't the array I'm looping through, so AFAIK I don't need to place an ampersand before it ("&$tree" shouldn't be necessary)... Plus a debug statement after the loop, checking $$varString, shows the modifications that should be visible just by checking $tree normally...

And some debug output that'll probably help to clarify what my code actually does:

code:
Function invoked!
$treeString ==
*Legend of Zelda: Ocarina of Time
**Index
**Glitches
***Swordless Link
****Poe Link
***Steal the Fishing Rod
**Videos
**Guides
**Secrets
**Cheats

$root == 1 so "*Legend of Zelda: Ocarina of Time" is the "root" of this list, and $offset = 1.

   Iteration! $level==1, $line==**Index,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Index']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==1, $line==**Glitches,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Glitches']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==2, $line==***Swordless Link,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Glitches']['Swordless Link']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==3, $line==****Poe Link,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Glitches']['Swordless Link']['Poe Link']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==2, $line==***Steal the Fishing Rod,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Glitches']['Steal the Fishing Rod']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==1, $line==**Videos,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Videos']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==1, $line==**Guides,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Guides']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==1, $line==**Secrets,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Secrets']
      [here, we set $$varString = array()]
      $$varString==Array
   Iteration! $level==1, $line==**Cheats,
      $varString==$tree['Legend of Zelda: Ocarina of Time']['Cheats']
      [here, we set $$varString = array()]
      $$varString==Array

Function complete.

And when we print_r $tree, we see:
(
    [Legend of Zelda: Ocarina of Time] => Array
        (
        )

)
...Which is weird, because $tree['Legend of Zelda: Ocarina of Time'] shouldn't be empty.

And when we print_r $$varString, we see:
Array
(
)
Which makes sense.

And when we print_r $curs, we see:
Array
(
    [0] => Legend of Zelda: Ocarina of Time
    [1] => Cheats
)



I am thoroughly confused.

----------------------


(Edited by DavidJCobb on 04-09-2009 23:28)

Tyberius Prime
Maniac (V) Mad Scientist with Finglongers

From: Germany
Insane since: Sep 2001

IP logged posted posted 04-10-2009 08:55 Edit Quote

I will bet even money that your $$ magic doesn't do what you think it does.
And you don't really need it.
Rework your code to live without it (use recursion, much cleaner).
Probably your last $$varString = array() just resets your $tree...

here, from the top of my head, untested...

code:
function createTree($lines, $depth = 1)
{
if (!is_array($lines))
  $lines = split("\n", lines);

$tree = array();
while (count($lines) > 0 )
{
$nextLine = array_unshift($lines);
$newDepth = strspn($nextLine,'*');
$lineName = substr($nextLine, $newDepth);
if ($newDepth == $depth)
{
   $tree[$lineName] = array();
   $lastName = &$lineName;
}
else
{
  $tree[$lineName] = createTree($lines, $depth + 1);
}
return $tree;
}



so long,

->Tyberius Prime



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