PHP - Somone Explain This Code?

Hi everyone!
I'm making friends with DOM+PHP+XML. I found an example in w3school tutorial but there are some things I don't understand.
Code: [Select]
<?php
$q=$_GET["q"];

$xmlDoc = new DOMDocument();
$xmlDoc->load("cd_catalog.xml");

$x=$xmlDoc->getElementsByTagName('ARTIST');

for ($i=0; $i<=$x->length-1; $i++)
{
//Process only element nodes
if ($x->item($i)->nodeType==1)
  {
  if ($x->item($i)->childNodes->item(0)->nodeValue == $q)
    {
    $y=($x->item($i)->parentNode);
    }
  }
}

$cd=($y->childNodes);

for ($i=0;$i<$cd->length;$i++)
{
//Process only element nodes
if ($cd->item($i)->nodeType==1)
  {
  echo("<b>" . $cd->item($i)->nodeName . ":</b> ");
  echo($cd->item($i)->childNodes->item(0)->nodeValue);
  echo("<br />");
  }
}
?> This part I understand, it's a PHP method:
Code: [Select]
$xmlDoc = new DOMDocument();
$xmlDoc->load("cd_catalog.xml");

$x=$xmlDoc->getElementsByTagName('ARTIST'); but I don't get the rest , and what is this Code: [Select]
$x->length-1 means? What does this mean? Code: [Select]
nodeType==1 what do the numbers represent?
Can anyone give me the URL of a good XML PHP tutorial?

Thank you

Hi guys, for a long time now I have been using the same block of code to include my content pages into my layout, I understand what it does as a whole, but I have never understood what the individual parts do, could someone explain the main parts please. Thanks.

here's the code:

Code: [Select]
<?php

    if (isset($_GET['page'])) 
{
    if (strpos($_GET['page'], "/")) 
{
    $direc = substr(str_replace('..', '', $_GET['page']), 0, strpos($_GET['page'], "/")) . "/";
    $file = substr(strrchr($_GET['page'], "/"), 1);
    if (file_exists($direc.$file.".php")) 
{
    require($direc.$file.".php");
} else {
    require("error.php");
}
} else {
    if (file_exists(basename($_GET['page']).".php")) 
{
    require(basename($_GET['page']).".php");
} else {
    require("error.php");
}
}
} else {
    require("default.php");
}
?>

I have some code that is supposed to get data from a site and then insert the gathered data into a database. The code does start adding data to database but it isn't adding data that it is getting from site that has starting data. What I mean is this. This code gets current player scores and such from gametracker and adds that to the database. then it will get player scores from my own tracker and add new scores to the ones that weere adde3d from game tracker. We did this so that our game servers continue tracking the scores for our new server trackers and not start out at zero initially. How ever when we run the code it says data was not written to database probably because server does not exists in database when in fact it really does. SO if someone could explain the code to me as to what it is doing then maybe I can figure out why it isn't working.

Code: [Select]
function InitializeServer( $sid, $ip, $name, &$totalplayers )
{
    !mysql_query( "DROP TABLE ".SERVER_TABLE_NAME.$sid.";" );    // we don't care if this fails if table didn't exist before
    if( !mysql_query( "CREATE TABLE ".SERVER_TABLE_NAME.$sid." ("
        ." `name` varchar(32), `score` int, `goal` int default 0, `leader` int default 0, `enemy` int default 0, `kia` int default 0, `roe` int default 0,"
        ." PRIMARY KEY(`name`) );" ) ) {
        die( "Error creating table: ".mysql_error() );
    }

    $id = 1;
    $page = 1;
    $done = FALSE;
    while( !$done ) {
        $data = http_request( "www.gametracker.com", "/server_info/".$ip."/top_players/?searchipp=50&searchpge=$page" );
        $pos = 0;
        $out = "";
        while( !$done ) {
            $num = GetStringInMiddle( $data, $pos, '<td class="c01">', '</td>' ); if( $num == NULL && $id > 1 ) break;
            if( $num != $id || $num == NULL ) { $done = TRUE; break; }
            $name = GetStringInMiddle( $data, $pos, '/">', '</a>' ); if( $name  === NULL ) break;
            $score = GetStringInMiddle( $data, $pos, '<td class="c04">', '</td>' );
            //$timePlayed  = GetStringInMiddle( $data, $pos, '<td class="c05">', '</td>' );
            //$scorePerMinute = GetStringInMiddle( $data, $pos, '<td class="c06">', '</td>' );
           
            if( $out != "" ) $out .= ",\n";
            $out .= "('$name', '$score')";
            $id ++;
            $totalplayers ++;
        }

        // Write data to database, if any               
        if( $out != "" )
        {
            $cmd = "INSERT INTO ".SERVER_TABLE_NAME.$sid." (`name`, `score`) VALUES ".$out.";";           
            if( !mysql_query( $cmd ) ) {
                echo "Error with insert: ".mysql_error()."\n[$cmd]";
            }
        }
        echo ($id-1)." "; flush(); ob_flush();
        $page++;
    }

    if( $id > 1 ) echo "\nInitalized server #$sid: ".$ip." - ".$name." - ".($id-1)." players added<br />";
    else echo "\nServer #$sid: ".$ip." - ".$name." - no players added (server probably not in database)<br />";

    flush(); ob_flush();
}

$sid, $ip and such are defined in other files that are included in the same file as this code is included in.

i found some code that is helping me extract a table. Currently it works and extracts every single table row however it duplicates some of the rows. I am new to XPATH and would appreciate if someone could comment the following code so that I can alter it to meet my needs. Thanks.

$newDom->appendChild($newDom->importNode($item,true));

   $xpath = new DOMXPath( $newDom ); 

   foreach ($item->attributes as $attribute) { 

    for ($node = $item->firstChild; $node !== NULL; 
         $node = $node->nextSibling) {
      if (($attribute->nodeName =='valign') && ($attribute->nodeValue=='top'))
      {
        print($node->nodeValue); 
      }
      else
      {
        print("<br>".$node->nodeValue);
      }
    }
    print("<br>");

I looked up 'how to get all POST variables' and I ended up putting this bit of code together.  Im not experienced at all with OOP programming, but I think that when '=>' is used its to do with OOP?  Anyway.  I dont get this code.  I understand Foreach $_POST, as $someVar, (BTW im looking for checkboxes from a form), However, If I leave out the '=> $val' I simply get a lot of 'on' values, indicating the checkboxes I checked.

However, WITH the '=> $val' I end up with the checkbox name.  Now i've changed the name of '$val' so i know its not a keyword.  But i dont get it.  Is there a way to access the value of the checkbox? Can someone explain to me whats going on here?  I know that I can get the value of the checkbox by $_POST['$checkRows'] But, I have a feeling It can be done in the foreach line.

foreach($_POST as $checkRows => $hip)
      {
         echo "POSTED: $checkRows<br>\n";         
      }

Please help!