Optimising my javascript/Ajax code

[xkratosx]

Hi guys,

I've wrote some Ajax (heavily inspired by the Livesearch on W3Tutorials may I add :P) that searches an xml document and outputs information accordingly.

It works kinda fine, but since the xml document is 200kb long, and it's looping through it like something crazy, it's taking a few minutes for every search and I've just managed to temporarily crash the web server :P

I'm after something that'll hopefully optimise the code, but I can't think for the life of me what the best way around this is.

Here's my Javascript code at present:

<?php
$xmlDoc = new DOMDocument();
$xmlDoc->load("get_xml.xml");
 
$x=$xmlDoc->getElementsByTagName('user');
 
//get the q parameter from URL
$q=$_GET["q"];
 
//lookup all links from the xml file if length of q>0
if (strlen($q) > 0)
{
$hint="";
for($i=0; $i<($x->length); $i++)
 {
 $y=$x->item($i)->getElementsByTagName('name');
 $z=$x->item($i)->getElementsByTagName('collar');
 if ($y->item(0)->nodeType==1)
  {
  //find a link matching the search text
  if (stristr($y->item(0)->childNodes->item(0)->nodeValue,$q))
   {
   if ($hint=="")
    {
    $hint="<a href='#' onclick='employee_form.Line_Manager_Staff_No.value=" . 
    $z->item(0)->childNodes->item(0)->nodeValue . 
    ";checknumber('Line_Manager_Staff_No','displayusername');'>" . 
    $y->item(0)->childNodes->item(0)->nodeValue . "</a>";
    }
   else
    {
    $hint=$hint . "<br /><a href='#' onclick='employee_form.Line_Manager_Staff_No.value=" . 
    $z->item(0)->childNodes->item(0)->nodeValue . 
    ";checknumber('Line_Manager_Staff_No','displayusername');'>" . 
    $y->item(0)->childNodes->item(0)->nodeValue . "</a>";
    }
   }
  }
 }
}
 
// Set output to "no suggestion" if no hint were found
// or to the correct values
if ($hint == "")
 {
 $response="no suggestion";
 }
else
 {
 $response=$hint;
 }
 
//output the response
echo $response;
?>

Any help would be awesome, thank you.

[cheap freelancer]

Move $x->length out of for loop

[xkratosx]

Thanks, so that it reads like this?

$x->length;
for($i=0; $i<($x); $i++)

Oh btw, here's my actual js file:

var xmlHttp
 
function showResult(str)
{
if (str.length==0)
 { 
 document.getElementById("livesearch").
 innerHTML="";
 document.getElementById("livesearch").
 style.border="0px";
 return
 }
 
xmlHttp=GetXmlHttpObject()
 
if (xmlHttp==null)
 {
 alert ("Browser does not support HTTP Request")
 return
 } 
 
var url="employee/live/livesearch.php"
url=url+"?q="+str
url=url+"&sid="+Math.random()
xmlHttp.onreadystatechange=stateChanged 
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
} 
 
function stateChanged() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 { 
 document.getElementById("livesearch").
 innerHTML=xmlHttp.responseText;
 document.getElementById("livesearch").
 style.border="1px solid #A5ACB2";
 } 
}
 
function GetXmlHttpObject()
{
var xmlHttp=null;
try
 {
 // Firefox, Opera 8.0+, Safari
 xmlHttp=new XMLHttpRequest();
 }
catch (e)
 {
 // Internet Explorer
 try
  {
  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  }
 catch (e)
  {
  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
return xmlHttp;
}

[jimfraser]

XML is notoriously slow - it would be quicker if your data was stored in a database and you did a sql lookup.

If you absolutely can't, maybe you can do a lookup using XPath to return only the xml nodes you want instead of manually looping and checking each one.

[xkratosx]

D'oh, many thanks for the reply, but yes that would be absolutely ideal!

All of the information is currently stored within a database and I'm currently trying to work out how to extract the information to the XML file on a daily basis, if I can bypass this and extract the information directly from the database (Oracle, fwiw) to the page that'd be utterly fantastic, especially if it'll be a lot quicker too!

Is it a fairly easy process?

Many thanks again

[jimfraser]

Yes it would be simple to convert this to use a database - not sure offhand of the syntax but check the PHP forum. Basically:
- connect to oracle database with php
- execute a query similar to:
"select name, collar from users where name like '%" . $q . "%'"
- loop through the results and create your $hint

[xkratosx]

Awesome, thank you so much! I'll admit I'm completely new to a lot of this, but I'll definitely give it my best show, cheers

[xkratosx]

jimfraser, just curious, I currently have the following code to output the bulk of my XML:

	    $xml_output .= "\t<user>\n";
$xml_output .= "\t\t<collar>" . oci_result($sqlListings, "Gc_Staff_Number") . "</collar>\n";
$xml_output .= "\t\t<name>" . oci_result($sqlListings, "Surname") . ", " . oci_result($sqlListings, "Forenames") . "</name>\n";
$xml_output .= "\t</user>\n";

Is that the section you would recommend I use/modify to create the hint?

Thanks

[jimfraser]

Right - you want to create the $hint string which contains html to display, and then output it.

It looks like oci_result is a recordset of sorts - so you'd loop through the recordset and create the <a> tags etc using the data contained.

if ($hint != "") {
	$hint .= "<br />";
}

$hint .= "<a href='#' onclick='employee_form.Line_Manager_Staff_No.value=" 
	. oci_result($sqlListings, "Gc_Staff_Number")
	. ";checknumber('Line_Manager_Staff_No','displayusername');'>" 
	. oci_result($sqlListings, "Surname") . ", " . oci_result($sqlListings, "Forenames")
	. "</a>";

[xkratosx]

Huge thanks once again for the reply and the code, really appreciate it!

I've thrown something together, it isn't working at the moment, I presume it's due to the second if statement although I'm not too sure... On a side note, what's 'displayusername'?

<?php
 
$network = new COM("WScript.Network");
include_once('../../../functions/datalib.php');
 
$db = new oracleClass();
$conn = $db->connect();
 
//get the q parameter from URL
$q=$_GET["q"];
 
//lookup all links from the xml file if length of q>0
if (strlen($q) > 0)
{
	$hint="";
 
	// connect to the database
	$sqlstatement = 'select * from TEST."WFO_REPORTS_ALLEMPS" order by "Surname", "Forenames"';
	$sqlListings = OCI_Parse($conn, $sqlstatement);
 
	OCI_Execute($sqlListings);
	while(OCI_Fetch($sqlListings)) {
 
		$name = oci_result($sqlListings, "Forenames") . ($sqlListings, "Surname")
 
		//find a link matching the search text
		if (strchr($name,$q))
		{
			if ($hint != "") {
				$hint .= "<br />";
			}
 
			$hint .= "<a href='#' onclick='employee_form.Line_Manager_Staff_No.value=" 
			. oci_result($sqlListings, "Gc_Staff_Number")
			. ";checknumber('Line_Manager_Staff_No','displayusername');'>" 
			. oci_result($sqlListings, "Surname") . ", " . oci_result($sqlListings, "Forenames")
			. "</a>";
		}
	}
}
 
// Set output to "no suggestion" if no hint were found
if ($hint == "")
 {
 $response="No user found.";
 }
else
 {
 $response=$hint;
 }
 
//output the response
echo $response;
?>

Thanks again, and help would be ace, I think I'm getting kinda close with this now

[jimfraser]

You don't need to check each record in the database to see if it's a match if you use a better SQL query that does it for you:

'select * from TEST."WFO_REPORTS_ALLEMPS" WHERE Surname=' . $q . ' order by "Surname", "Forenames"';

Then you can eliminate
//find a link matching the search text if (strchr($name,$q))

[xkratosx]

Huge thanks for the info, that's a very good idea actually and will help improve the efficiency no end! For some reason though it still isn't working, when I type something into the box nothing is displayed

Also, a complete longshot, is there anyway to get it so that it'll select according to both the sirname and first name? Fore example the name John Smith, if you type in John it'll bring up the name, and likewise if you type in Smith it'll bring up the name?

[jimfraser]

All of that can be accomplished by using the correct SQL query. That (and php heh) is out of the scope of this particular forum however, and something that perhaps could be answered better by a real SQL expert.

[xkratosx]

Ah thank you, I'll do a post on the PHP forum then (or the SQL one!) and see how I get on.

Once again a massive thanks for all of your help, I really, really appreciate it!