Read attributes of first and children elements with SAX XML Parser in PHP

After some research on the internet I realized that SAX XML Parser was the best option for me, since I was looking for the fastest XML Parser for large (really large) xml files.

So I was working on this codes I found in a tutorial and it works pretty nice indeed, I just couldn't figure out how to read the first and secondary element's attributes, just what's inside each element.

Here is the code:

XML

<?xml version="1.0" encoding="iso-8859-1"?>
<items>
    <item id="100" name="First Element 1" />
    <item id="101" name="First Element 2" />
    <item id="102" name="First Element 3" />
    <item id="103" name="First Element 4">
        <attribute name="Second Element 4" value="508" />
    </item>
    <item id="104" name="First Element 5" />
    <item id="105" name="First Element 6">
        <attribute name="Second Element 6" value="215" />
    </item>
</items>

PHP

$items = array();
$elements = null;
$item_attributes = null; //I added that myself, not sure if it's correct

// Called to this function when tags are opened 
function startElements($parser, $name, $attrs) {
    global $items, $elements, $item_attributes; // <-- added it here aswell

    if(!empty($name)) {
        if ($name == 'ITEM') {
            if (!empty($attrs['ID'])) {
                $item_attributes []= array(); // <-- here aswell
            }
            // creating an array to store information
            $items []= array();
        }
        $elements = $name;
    }
}

// Called to this function when tags are closed 
function endElements($parser, $name) {
    global $elements;

    if(!empty($name)) {
        $elements = null;
    }
}

// Called on the text between the start and end of the tags
function characterData($parser, $data) {
    global $items, $elements;

    if(!empty($data)) {
        if ($elements == 'ATTRIBUTE') {
            $items[count($items)-1][$elements] = trim($data);
        }
    }
}

// Creates a new XML parser and returns a resource handle referencing it to be used by the other XML functions. 
$parser = xml_parser_create(); 

xml_set_element_handler($parser, "startElements", "endElements");
xml_set_character_data_handler($parser, "characterData");

// open xml file
if (!($handle = fopen('./pages/scripts/sax.xml', "r"))) {
    die("could not open XML input");
}

while($data = fread($handle, 4096)) {
    xml_parse($parser, $data);  // start parsing an xml document 
}

xml_parser_free($parser); // deletes the parser
$i = 1;

foreach($items as $course) {
    echo $i.' -';
    echo ' ITEM ID: '.$course['ID'].'(?),';
    echo ' NAME: '.$course['NAME'].'(?)<br/>';
    echo 'ATTRIBUTE NAME: ???,';
    echo ' ATTRIBUTE VALUE: ???<hr/>'; // not sure how to pull those results
    $i++; 
}

So I was trying to get the id and name from the tag item and the name and value from the tag attribute inside the first element item...

Any ideas?

UPDATE: Note: The course['ID'] and course['NAME'] isn't echoing anything, but when I use course['ITEM'] or course['ATTRIBUTE'] it echoes whatever is inside the tag item or attribute ex: <item> this </item>, and what I want to get is: <item THIS="this" />

Solution

I would do this a little bit different of your way, but It still goes for the same porpoise...

I know this isn't a very practical method but I think it'll do for you... You'll also be able to get the elements attribute more than once if it existed:

Note that at start_element function you can edit the attributes of both item and attribute elements in the arrays of the variables $item_attr and $field_attr.

I would also recommend you to run this code entirely so you can see what it prints and then feel free to edit it as you wish.

XML:

<?xml version="1.0" encoding="iso-8859-1"?>
<items>
    <item id="100" name="First Element 1" />
    <item id="101" name="First Element 2" />
    <item id="102" name="First Element 3" />
    <item id="103" name="First Element 4">
        <attribute name="Second Element 4" value="508" />">
        <attribute name="Third Element 4" value="509" />
    </item>
    <item id="104" name="First Element 5" />
    <item id="105" name="First Element 6">
        <attribute name="Second Element 6" value="215" />
    </item>
</items>

PHP

<?php
    $GLOBALS['currentIndex'] = 0; // identify where you are at in each element item
    $GLOBALS['currentAttrIndex'] = 0; // the same but for the element attribute
    $GLOBALS['currentField'] = ''; // specifies the element inside item
    $GLOBALS['items'] = array(); // creates the array for the elements in items
    $GLOBALS['attrs'] = array(); // creates the array for the elements attributes (in case of more than one)
    $GLOBALS['items_attr'] = '';
    $GLOBALS['fields_attr'] = '';

    $parser = xml_parser_create();
    xml_set_element_handler($parser, 'start_element', 'end_element');
    xml_set_character_data_handler($parser, 'cdata');
    xml_parse($parser, file_get_contents('./pages/test/sax.xml'), true);
    xml_parser_free($parser);

    //display results in a familiar way as a debugger...
    $items = $GLOBALS['items'];
    $attrs = $GLOBALS['attrs'];
    $items_attr = $GLOBALS['items_attr'];
    $fields_attr = $GLOBALS['fields_attr'];
    $i = 1;
    if (count($items) > 0) {
        foreach($items as $item){
            echo 'START ITEM</br>';
            echo ($items_attr[$i-1]['id'] ? 'ID: '.$items_attr[$i-1]['id'].'</br>' : '');
            echo ($items_attr[$i-1]['name'] ? 'NAME: '.$items_attr[$i-1]['name'].'</br>' : '');
            $a = 0;
            foreach ($attrs as $attr_id => $attr_name) {
                if($attr_id == $i-1){
                    $g_i_attr_bits = explode(",", substr($attr_name, 0, -1));
                    foreach($g_i_attr_bits as $g_i_at_b){
                        $a++;
                        echo '&emsp;&emsp;START ATTRIBUTE</br>';
                        echo ($fields_attr[$g_i_at_b]['name'] ? '&emsp;&emsp;;&emsp;NAME: '.$fields_attr[$g_i_at_b]['name'].'</br>' : '');
                        echo ($fields_attr[$g_i_at_b]['value'] ? '&emsp;&emsp;;&emsp;VALUE: '.$fields_attr[$g_i_at_b]['value'].'</br>' : '');
                        echo '&emsp;&emsp;END ATTRIBUTE</br>';
                    }
                }
            }
            if($a > 0){
                echo 'END ITEM</br></br>';
            }
            $i++;
        }
    }

    function start_element($parser, $name, $attributes){
        switch($name){
            case 'ITEM':
                $item = array('attribute'=>'');
                $GLOBALS['items'][] = $item;
                $item_attr = array('id'=>''.$attributes['ID'].'','name'=>''.$attributes['NAME'].'');
                $GLOBALS['items_attr'][] = $item_attr;
            break;
            case 'ATTRIBUTE':
                $field_attr = array('name'=>''.$attributes['NAME'].'','value'=>''.$attributes['VALUE'].'');
                $GLOBALS['fields_attr'][] = $field_attr;
                $GLOBALS['currentField'] = 'attribute';
                $attr .= $GLOBALS['currentAttrIndex'].',';
                $GLOBALS['attrs'][$GLOBALS['currentIndex']] .= $attr;
            break;
        }
    }

    function end_element($parser, $name){
        switch($name){
            case 'ITEM':
                $GLOBALS['currentIndex']++;
            break;
            case 'ATTRIBUTE':
                $GLOBALS['currentAttrIndex']++;
            break;
        }
    }

    function cdata($parser, $data){
        $currentIndex = $GLOBALS['currentIndex'];
        $currentField = $GLOBALS['currentField'];
        if($data != ''){
            $GLOBALS['items'][$currentIndex][$currentField] = $data;
        }
    }
?>