Need to manipulate XML document trees, but don't have the DOM extension compiled into your PHP build? Take a look at XMLTree, a PEAR class that allows you to create and manipulate XML document trees without requiring the PHP DOM extension.
Now, while all this is fine and dandy, how about using all this new-found knowledge for something practical?
This next example does just that, demonstrating how the XMLTree class can be used to convert data stored in a MySQL database into an XML document, and write it to a file for later use. Here's the MySQL table I'll be using,
+----+------------------+-----------------------------------+-----------
+----+------------------+-----------------------------------+----
--+----------------+
|
id | name | address | tel
|fax
|
+----+------------------+-----------------------------------+-----------
+----+------------------+-----------------------------------+----
--+----------------+
|
1 | Sam Spade | 134, Dark Road, New York, NY |
1-800-TOUGH-GUY |1-234-587-3636
|
| 2 | The White Rabbit | Down The Rabbit Hole, Wonderland | 56-78-5467
|56-78-2537
|
| 3 | Jack Liliput | The Little House, Lilliput Island
| None
|None
|
+----+------------------+-----------------------------------+-----------
+----+------------------+-----------------------------------+----
--+----------------+
and here's what I want my target XML document to look like:
<?xml version="1.0"?>
<addressbook>
<item id="1">
<name>Sam
Spade</name>
<address>134, Dark Road, New York, NY</address>
<tel>1-800-TOUGH-GUY</tel>
<fax>1-234-587-3636</fax>
</item>
<item
id="2">
<name>The White Rabbit</name>
<address>Down The Rabbit
Hole, Wonderland</address>
<tel>56-78-5467</tel>
<fax>56-78-2537</fax>
</item>
<item id="3">
<name>Jack
Liliput</name>
<address>The
Little House, Lilliput Island</address>
<tel>None</tel>
<fax>None</fax>
</item>
</addressbook>
With XMLTree, accomplishing this is a matter of a few lines of code. Here they
are:
<?php
// include class
include("Tree.php");
// set output filename
$filename
= 'addressbook.xml';
// instantiate object
$tree = new XML_Tree();
// add
the
root element
$root =& $tree->addRoot("addressbook");
// open connection
to
database
$connection = mysql_connect("localhost", "joe", "secret") or die
("Unable
to
connect!");
// select database
mysql_select_db("db567") or die
("Unable
to
select database!");
// execute query
$query = "SELECT * FROM addressbook";
$result
= mysql_query($query) or die ("Error in query: $query. " .
mysql_error());
//
iterate through rows and print column data
while ($row = mysql_fetch_array($result))
{
//
add child elements
$item =& $root->addChild("item", NULL, array("id" =>
$row['id']));
$name
=& $item->addChild("name", $row['name']);
$address
=& $item->addChild("address",
$row['address']);
$tel =& $item->addChild("tel",
$row['tel']);
$fax =&
$item->addChild("fax", $row['fax']);
}
// close
database connection
mysql_close($connection);
//
open file
if (!$handle = fopen($filename,
'w'))
{
print "Cannot open file ($filename)";
exit;
}
//
write XML to file
if
(!fwrite($handle, $tree->get()))
{
print "Cannot write
to file ($filename)";
exit;
}
//
close file
fclose($handle);
?>
Pretty simple, once you know how it works. First, I've opened up a connection
to the database and retrieved all the records from the table. Then I've instantiated a new document tree and iterated over the result set, adding a new set of nodes to the tree at each iteration. Finally, once all the rows have been processed, the dynamically generated tree is written to a file for later use.
