[SOLVED] call a php function and return the value?

[Dragen]

Hi,

I've got a php script which takes an x and y coordinate and gets the pixel colour from an image with those coordinates:

<?php
class getcolor{
function getcolor($x, $y){
	$image  = @imagecreatefrompng('palette.png');
	$x  = (integer) $x;
	$y  = (integer) $y;

	if($image){
		$color  = ImageColorAt($image, $x, $y);
		$r  = ($color >> 16) & 0xFF;
		$g  = ($color >>  & 0xFF;
		$b  = $color & 0xFF;

		$this->color = $this->gethex($r, $g, $b);
	}else{
		return false;
	}
}

function gethex($r, $g, $b){
	return strtolower(sprintf('#%02X%02X%02X', $r, $g, $b));
}
}

$getcolor = new getcolor(50, 86);
// the colour is stored as hex in the variable: $getcolor->color;
?>

 

Now what I want to do is use ajax to create an onclick event which calls up the getcolor function with the specified x and y, then retrieves the given value.

 

How can I send and recieve from a php file with ajax? I've seen something in javascript about the call metho, but am unsure if this is the right direction.

 

Thanks

[Dragen]

nevermind. I've figured it out.. javascript syntax is really driving me nuts though

 

here's my solution:

 

getcolor.php:

<?php
class getcolor{
function getcolor($x, $y){
	$this->color = 'n/a';
	$image  = @imagecreatefrompng('palette.png');
	$x  = (integer) $x;
	$y  = (integer) $y;

	if($image){
		$color  = ImageColorAt($image, $x, $y);
		$r  = ($color >> 16) & 0xFF;
		$g  = ($color >>  & 0xFF;
		$b  = $color & 0xFF;

		$this->color = $this->gethex($r, $g, $b);
	}
}

function gethex($r, $g, $b){
	return strtolower(sprintf('#%02X%02X%02X', $r, $g, $b));
}
}

if((isset($_GET['x']) && isset($_GET['y'])) && (ctype_digit($_GET['x']) && ctype_digit($_GET['y']))){
$getcolor = new getcolor($_GET['x'], $_GET['y']);
}else{
$getcolor->color = 'n/a';
}

echo $getcolor->color;
?>

as you can see, at the end I echo out the variable.

 

Then I have an onclick event which calls the javascript getcolor function:

<a href="#" onclick="javascrip:javascript:getcolor(X, Y);">click here</a> //x and y are my x and y coordinates

The javascript looks like this:

var xmlhttp

function getcolor(x, y){
xmlhttp=null
// code for Mozilla, etc.
if (window.XMLHttpRequest)
  {
  xmlhttp=new XMLHttpRequest()
  }
// code for IE
else if (window.ActiveXObject)
  {
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")
  }
  
if (xmlhttp!=null)
  {
  xmlhttp.onreadystatechange=state_Change
  xmlhttp.open("GET","/admin/includes/getcolor.php?x="+x+"&y="+y,true)
  xmlhttp.send(null)
  }
else
  {
  alert("Your browser does not support XMLHTTP.")
  }
}

function state_Change()
{
// if xmlhttp shows "loaded"
if (xmlhttp.readyState==4)
  {
  if (xmlhttp.status==200)
    {
	var response = xmlhttp.responseText;
		alert('response: '+response);
    }
  else
    {
    alert("Problem retrieving XML data")
    }
  }
}

 

Which correctly gives me anything that is output from my php file. All I need to do now is get it to put the value into a text input, which should be fairly easy.