I've been using this script which i got from the kirupa forums a while back to update xml files. Its quite straightforward to modify, and works quite nicely.
index.php<div id="container">
<div id="uploadTag"><IFRAME id=newsiframe name=newsiframe marginWidth=0 marginHeight=0 src="images/image_upload.php" frameBorder=0 width=420 scrolling=yes height=200>Your browser doesn't support iframes. Please click <a href="images/image_upload.php">here</a> to see the content.</IFRAME>
</div>
<div id="xmlTag">
<h3>Step 2 - Update the Gallery</H3>
<form action="processForm.php" method="post">
<fieldset>
<label for="name">Description:</label> <input type="text" id="name" name="name"/><br />
<label for="source">Filename:</label><input type="text" id="source" name="source" /><br />
<label for="thumb">Thumbnail:</label> <input type="text" id="thumb" name="thumb" /> <br />
<select name="action">
<option value="ins">Insert</option>
<option value="del">Delete</option>
</select>
<input type="submit" />
</fieldset>
</form>
<p>Current entries:</p>
<?php
function start_tag($parser, $name, $attrs){
global $table_string;
$table_string .= "<tr><td>$attrs[title]</td><td>$attrs[source]</td><td>$attrs[thumb]</td></tr>";
}
function end_tag($parser, $name){}
$parser = xml_parser_create();
xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
xml_set_element_handler($parser, "start_tag", "end_tag");
$table_string = "<table>
<tr><th>DESCRIPTION</th><th>FILENAME</th><th>THUMBNAIL NAME</th></tr>";
xml_parse($parser, file_get_contents("gallery.xml")) or die("Error parsing XML file");
$table_string .= "</table>";
echo $table_string;
?>
and
processForm.php
<?
$songs = Array();
function start_element($parser, $name, $attrs){
global $songs;
if($name == "image"){
array_push($songs, $attrs);
}
}
function end_element ($parser, $name){}
$playlist_string = file_get_contents("gallery.xml");
$parser = xml_parser_create();
xml_set_element_handler($parser, "start_element", "end_element");
xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
xml_parse($parser, $playlist_string) or die("Error parsing XML document.");
print "<br />";
if($_POST['action'] == "ins"){
array_push($songs, Array(
"title" => $_POST['name'],
"source" => $_POST['source'],
"thumb" => $_POST['thumb']));
$songs_final = $songs;
}else if($_POST['action'] == "del"){
$songs_final = Array();
foreach($songs as $song){
if($song['title'] != $_POST['name']){
array_push($songs_final, $song);
}
}
}
$write_string = '<portfolio cols="12">';
foreach($songs_final as $song){
$write_string .= "\n<image title=\"$song[title]\" source=\"$song[source]\" thumb=\"$song[thumb]\" />\n";
}
$write_string .= '</portfolio>';
$fp = fopen("gallery.xml", "w+");
fwrite($fp, $write_string) or die("Error writing to file");
fclose($fp);
print "<em>Image inserted or deleted successfully</em><br />";
print "<a href=\"index.php\" title=\"return\">Return</a>";
?>
It was originally for an mp3 playlist but i've used i a couple of times to work with image galleries.
Hope this is what ypu're looking for.
Dave