bjori

Note Submitter: andrewcare at execulink dot com

----

I've been working on a similiar tree-based generator (although somewhat simpler), and I thought that it might be helpful to a developer just starting out:

http://www.drmatta.com/new/xml/

Simplified source:

<?
$file = /*File to be parsed*/;
$elements = $stack = array();
$count = $depth = 0;

class element{
var $name = '';
var $attributes = array();
var $data = '';
var $depth = 0;
}

function start_element_handler($parser, $name, $attribs){
global $elements, $stack, $count, $depth;

$id = $count;
$element = new element;
$elements[$id] = $element;

$elements[$id]->name = $name;

while(list($key, $value) = each($attribs))
$elements[$id]->attributes[$key] = $value;

$elements[$id]->depth = $depth;

array_push($stack, $id);

$count++;
$depth++;
}

function end_element_handler($parser, $name){
global $stack, $depth;

array_pop($stack);

$depth--;
}

function character_data_handler($parser, $data){
global $elements, $stack;

$elements[$stack[count($stack)-1]]->data .= $data;
}

$xml_parser = xml_parser_create('');

xml_parser_set_option($xml_parser, XML_OPTION_CASE_FOLDING, 0);

xml_set_element_handler($xml_parser, "start_element_handler", "end_element_handler");
xml_set_character_data_handler($xml_parser, "character_data_handler");

if(!file_exists($file))
die("\n<p>\"$file\" does not exist.</p>\n</body>\n</html>");

if(!($handle = fopen($file, "r")))
die("<p>Cannot open \"$file\".</p>\n</body>\n</html>");

while($contents = fread($handle, 4096))
xml_parse($xml_parser, $contents, feof($handle));

fclose($handle);

xml_parser_free($xml_parser);

echo "<hr />\n";

$depth = $offset = 0;

while(list($key_a) = each($elements)){
$depth--;
$offset = 0;
if($elements[$key_a]->depth < $depth){
while($elements[$key_a]->depth != (($elements[$key_a - $offset]->depth) - 1) || $offset == 0){
$offset++;
if($elements[$key_a]->depth == (($elements[$key_a - $offset]->depth) - 1))
echo "<dl>\n<dt><strong>Element Closed:</strong></dt>\n<dd>" . $elements[$key_a - $offset]->name . "</dd>\n</dl>\n<hr />\n";
}
$depth--;
}
if($elements[$key_a]->depth == $depth && $depth != 0){
while($elements[$key_a]->depth != $elements[$key_a - $offset]->depth || $offset == 0){
$offset++;
if($elements[$key_a]->depth == $elements[$key_a - $offset]->depth)
echo "<dl>\n<dt><strong>Element Closed:</strong></dt>\n<dd>" . $elements[$key_a - $offset]->name . "</dd>\n</dl>\n<hr />\n";
}
$depth--;
}
$depth++;
echo "<dl>\n<dt><strong>Element:</strong></dt>\n<dd>" . $elements[$key_a]->name . "</dd>\n</dl>\n";
echo "<dl>\n<dt><strong>Attributes:</strong></dt>\n";
if(empty($elements[$key_a]->attributes))
echo "<dd>No attributes specified</dd>\n";
else{
while(list($key_b, $value) = each($elements[$key_a]->attributes))
echo "<dd>$key_b=\"$value\"</dd>\n";
}
echo "</dl>\n<dl>\n<dt><strong>Data:</strong></dt>\n";
if(trim($elements[$key_a]->data) == '')
echo "<dd>No data specified</dd>\n";
else
echo "<dd>" . $elements[$key_a]->data . "</dd>\n";
echo "</dl>\n<dl>\n<dt><strong>Depth:</strong></dt>\n<dd>" . $elements[$key_a]->depth . "</dd>\n</dl>\n<hr />\n";
$depth++;
}

$depth--;

for($i = $depth; $i >= 0; $i--){
$offset = 0;
$count = count($elements) - 1;
for($j = 0; $j <= $count; $j++){
if($elements[$count - $j]->depth == $depth){
echo "<dl>\n<dt><strong>Element Closed:</strong></dt>\n<dd>" . $elements[$count - $j]->name . "</dd>\n</dl>\n<hr />\n";
break;
}
}
$depth--;
}
?>

A few good tutorials on the subject of parsing XML with PHP:

http://www.zend.com/zend/art/parsing.php
http://www.sitepoint.com/article/560/