//initialize vars
$begin=time(); // script start time
$filenum = 1; // start chunk file number at 1
$recordnum = 0; // start at record 1
//file settings
$basefilename = "chunks"; // the base file name for the chunks
$xmlfile = "TURL0001.XML"; // the xml file name to be processed
$xmldatadelimiter = "ONIXmessage"; // core data delimiter
$xmlitemdelimiter = "product"; // record delimiter
$chunksize = "2000"; // number of records in each chunk file
$xmlheader ="\n";
$xmlheader.="<$xmldatadelimiter>\n"; // xmlchunk file header
//dirs and files
$dir = ""; // path to where splits will be stored
$exportfile = "$dir"."$basefilename-".str_pad($filenum, 4, "0",STR_PAD_LEFT).".xml";
echo "Processing (".$dir."/$xmlfile)\n";

if ($recordnum>$chunksize) {//when recordnum more then chunksize do end file
preg_match("(<\/$xmlitemdelimiter>)", $buffer, $hit, PREG_OFFSET_CAPTURE); // find end item tag in buffer
if ($hit){//set file point back to end item tag and remove data after end tag form buffer
$str = $hit[0][0];
$pos = (int)$hit[0][1];
$buff_length = strlen($buffer);
$curr_pointer = ftell($handle);
$new_pointer = $curr_pointer-$buff_length+$pos+strlen($str);
fseek($handle, (int)$new_pointer);
$buffer = substr($buffer,0,$pos+strlen($str));
}
error_log("$buffer",3,$exportfile);//write the last piece of chunk file
error_log("",3,$exportfile);//write close data tag
$recordnum = 0; //reset counter
$filenum++;
$exportfile = "$dir"."$basefilename-".str_pad($filenum, 4, "0",STR_PAD_LEFT).".xml"; //create next chunk file
echo"Segment $filenum. Record ".($chunksize*$filenum).".\n";
error_log($xmlheader,3,$exportfile);
}else{
error_log("$buffer",3,$exportfile); //write buffer to chunk file
}
}
fclose($handle);
}else{
echo"Unable to open file! (".$dir.$xmlfile.")\n";
}
$procend = time();
echo "\n####\n";
echo "Split Complete (".floor((($procend-$begin)/60))." Minutes)\n";
$end = microtime(true);
$time = $end - $start;
print "parse time: $time seconds
";
?>
but this code isn’t 100% perfect because it’s to slow if I modify more.

source code and example xml: source

สามารถเรียกใช้ constructor โดย:

var obj = new Image([width], [height]);


Properties ที่ใช้บ่อยๆ:

properties	description
height	set or return image’s height
width	set or return image’s width
src	set or return URL source
name	set or return image’s name

Events:

event	description
onload	execute when successful and complete to download image
onabort	execute when user abort download image
onerror	execute when error occur while loading image (image not found)

more source: w3schools, mozilla developer center

example image preloading:

html code:


javascript code in example.js:function change_img(url){
document.images.loading_img.src = 'images/loading.gif';//show loading image
var img = new Image();
img.onload = function(){
document.images.loading_img.src = url;//change image when loading complete
}
img.src = url;//preload image
}
function onclick_thumb(){
var e = arguments[0] || window.event;//get event object, note: this fix for IE
var target_img = e.target || e.srcElement;//get target object (ie: image object), note: this fix for IE
var url = target_img.getAttribute('rel');//get url form attricute 'rel'
change_img(url);
}
function init_example(){
var thumb_obj = document.getElementById('thumb_container').getElementsByTagName('img');//get thumbnail image's objects
for(var i in thumb_obj){
thumb_obj[i].onclick = onclick_thumb;//add onclick event for each object
}
var img = new Image();
img.src = 'images/loading.gif';//preloading loading image
}
if(window.addEventListener){
window.addEventListener("load", init_example, false); //run initial fuction when complete loading object
}else if(window.attachEvent){
window.attachEvent("onload",init_example);//fix run initial fuction for fucking browser(IE)
}

demo here
source here

';
print "parse time: $time seconds
";
print "memory usage before resize: $mem_before
memory peak while resize: $mem_after
memory usage for resize:".($mem_after-$mem_before);
?>
result here:

test resize 440×504 image by GD lib
code here:
function resize($img, $w, $newfilename) {

';
print "parse time: $time seconds
";
print "memory usage before resize: $mem_before
memory peak while resize: $mem_after
memory usage for resize:".($mem_after-$mem_before);
?>
result here:

source code including statically linked Image Magick V4: source

sample xml:



Gambardella, Matthew

sample to use Xpath by php:
function getSelectXpathValue(&$xpath,$expression){
$obj = $xpath->xpath_eval($expression);
$value = array();
if(@count($obj->nodeset)){
foreach($obj->nodeset as $node){
$value[] = $node->get_content();
}
}
return $value;
}

)
*/
$value = getSelectXpathValue($xpath, "/catalog/book[genre='Fantasy'][description]/title");
print_r($value);
/* output is:
Array
(
[0] => Midnight Rain
[1] => Maeve Ascendant
)
*/
$value = getSelectXpathValue($xpath, "//title");
print_r($value);
/* output is:
Array
(
[0] => XML Developer's Guide
[1] => Midnight Rain
[2] => Maeve Ascendant
[3] => Oberon's Legacy
[4] => The Sundered Grail
[5] => Lover Birds
[6] => Splish Splash
[7] => Creepy Crawlies
[8] => Paradox Lost
[9] => Microsoft .NET: The Programming Bible
[10] => MSXML3: A Comprehensive Guide
[11] => Visual Studio 7: A Comprehensive Guide
)
*/
?>

DOM (Document Object Model) คือวิธีจัดการกับ XML อย่างหนึ่งโดย แทน node ต่างๆใน file ด้วย object ทำให้การเข้าถึง node ต่างๆทำได้ง่ายขึ้น โดยการใช้ method ของ object แต่การจะสร้าง object จาก XML จะต้อง parse XML ทั้งหมดลง memory ทำให้วิธีนี้ไม่เหมาะที่จะใช้กับ file XML ที่มีขนาดใหญ่ ถ้าไม่เชื่อลองได้โดยเอา XML ขนาด 10 MB ไปเปิดกับ browser อย่าง IE หรือ firefox ดูเพราะ browser ทั่วไปใช้ DOM จัดการกับ file ลักษณะ XML อยู่แล้ว ฉะนั้นจึงมีอีกวิธีหนึ่งที่จัดการกับ XML นั้นก็คือ SAX


SAX (Simple API for XML) เป็นวิธีการจัดการ XML โดย access แต่ละ node ไปตามลำดับ จนจบ file โดยจะใช้ event จัดการกับแต่ละ node event ของ SAX ประกอบไปด้วย

• Processing Instruction (ส่วนที่ใช้ describe XML: )
• Element nodes (แบ่งเป็น 2 eventคือ start element, end element)
• Text nodes
• Comments

ตัวอย่างการใช้ SAX กับ php

Sample xml:books.xml
sample php code:
class BookSax{
var $current_data = array();
function start_element($parser, $name, $attrs){
//checking interest node and setting need data
if($name == 'book'){
$this->current_data['id'] = $attrs['id'];
}
if($name == 'title'){
$this->get_data = 'title';
}
if($name == 'price'){
$this->get_data = 'price';
}
}
function end_element($parser, $name){
//print data when get all boook's data
if($name == 'book'){
print 'ID: '.$this->current_data['id']
.' TITLE: '.$this->current_data['title']
.' PRICE: '.$this->current_data['price'].'
';
//clear previous boook's data
$this->current_data = array();
}
}
function text($parser, $text){
//collecting need data
if(!empty($this->get_data)){
$this->current_data[$this->get_data] = $text;
$this->get_data = NULL;
}
}
}

if($fp = fopen('books.xml', "r")){
//read xml file
while ($data = fread($fp, 4096)){
$this_chunk_parsed = xml_parse($parser, $data, feof($fp));//do parse data and excute callback
if (!$this_chunk_parsed) {
$error_code = xml_get_error_code($parser);
$error_text = xml_error_string($error_code);
$error_line = xml_get_current_line_number($parser);
$output_text = "Parsing problem at line $error_line: $error_text";
die($output_text);
}
}
}
fclose($fp);
xml_parser_free($parser);
?>

result here:

code here: source