A little bit about XML parsing...

hsn

Hi,

I'm trying to make use of XML parser in php. But things are confusing! All what I found are some implementations without explaining the actual job inside of the code..! I need to undrestand the theory first and then coding is not a big deal...

For example...:

What is this function about:

xml_set_element_handler($parser, 'start_element', 'end_element');

And what should be inside of start_element() and end_element() ?

Why do we need these things...? 🙂

Can anyone help me? 🙂

diego25

Have you searched for xml_set_element_handler in the PHP Documentation?

Diego

hsn

yea I searched for it but unfortunately, there wasn't useful information... !

Weedpacket

Well, that's all the information that everyone else who uses xml_set_handler had to go on (unless they wrote the original function themselves - but then they wrote the manual). The things you're asking about are supposed to be the names of functions. The first one is called when an opening tag is seen, the second one is called when a closing tag is seen.

hsn

Yea I figured it out and made the following code:

<?php

$element = array();
$all = array();
$parser = xml_parser_create();

xml_set_element_handler($parser, 'start_element', 'end_element');
xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, 0);
xml_set_character_data_handler($parser, 'handler');

$fp = @fopen('data.xml', 'r');
$xmlsource = fread($fp, 4096);

if(!xml_parse($parser, $xmlsource, 1)) {
    $line  = xml_get_current_line_number($parser);
    $error = xml_error_string(xml_get_error_code($parser));
    die ("XML error: $error in parser at line $line");
}

function start_element($parser, $name, $attribs) {
    global $cur;
    $cur = $name;
}

function end_element($parser, $name) {
    global $element, $all;
    $all[] = $element;
}

function handler($parser, $data) {
    global $cur, $element;

switch($cur) {
case 'main':
    $element[$cur] = $data;
    break;
}
}

while(list($key, $val) = each($element)) {
    echo "$key => $val<br>";
}

?>

but.. now the problem is that... the last two lines only prints the $key and $val is always empty!! I donno why..!!