How To Parsing a Simple XML Document in PHP
Here is an example of an XML document and the steps needed to parse that document:
test.xml — The XML file we parse.
<?xml version="1.0"?>
<book>
<chapter id="1">
<title>Chapter 1</title>
<contents>
The Contents of chapter one go here.
</contents>
</chapter>
<chapter id="2">
<title>Chapter 2</title>
<contents>
The Contents of chapter two go here.
</contents>
</chapter>
</book></code>
xml-test.php — The PHP program to parse the XML file.
<?php
function start_element($parser, $element_name, $element_attrs)
{
switch ($element_name) {
case "CHAPTER":
print "<a name=\"#$element_name{$element_attrs['ID']}\"></a>";
break;
case "TITLE":
print ‘<h2>’;
break;
case "CONTENTS":
print ‘<font face="arial" size="2">’;
break;
}
}
function end_element($parser, $element_name) {
switch ($element_name) {
case "TITLE":
echo "</h2>\n";
break;
case "CONTENTS":
echo "</font>\n<br><br>";
break;
}
}
function character_data($parser, $data) {
echo $data;
}
$parser = xml_parser_create();
xml_set_element_handler($parser, ’start_element’, ‘end_element’);
xml_set_character_data_handler($parser, ‘character_data’);
$fp = fopen(’test.xml’, ‘r’) or die(’Cannot open test.xml’);
while ($data = fread($fp, 4096)) {
xml_parse($parser, $data, feof($fp))
or die(sprintf(’XML Error: %s at line %d’,
xml_error_string(xml_get_error_code($parser)),
xml_get_current_line_number($parser)));
}
xml_parser_free($parser);
?>
PHP connects to the Expat C API, so if you have used Expat before, the example in the synopsis should look somewhat familiar. If you haven’t used Expat before, let me explain a little bit about the theory involved in parsing XML documents.
Expat uses a SAX-type XML parser, meaning that it uses handlers for the different types of events that may occur. When an event occurs, the data is passed to these different handlers, along with information related to the data. Let’s consider the XML document in the preceding “Technique” section: On the start of an element (
No comments yet. Be The First!