Using the image library within functions

[tiki]

I have a form checking class I wrote and im currently writing a method that creates a captcha image, but im relatively new to the image library. Every way ive seen a captcha made it uses a seperate file, is it possible to create the image using a method. Heres my current method, its entirely a work in progress.

 

	public function captcha($height, $width, $bgColor = "", $textColor = "", $options = "") {
	header ("Expires: Sat, 10 Dec 1983 07:00:00 GMT");
    	header ("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
    	header ("Cache-Control: no-cache, must-revalidate");  // HTTP/1.1
    	header ("Pragma: no-cache");                          // HTTP/1.0
    	header ("Content-type: image/gif");

	// If no bg color / text color / options set
	if (!is_array($bgColor)) {
		$bgColor = array(
			"red"	=> 0,
			"blue"	=> 0,
			"green"	=> 0
		);
	}

	if (!is_array($textColor)) {
		$textColor = array(
			"red"	=> 255,
			"blue"	=> 255,
			"green"	=> 255
		);
	}

	if (!is_array($options)) {
		$options = array(
			"font" => 1,
			"x"	=> 5,
			"y"	=> 5
		);
	}

	// Create the image
        $image = imagecreate($width, $height);
        $image_bg = imagecolorallocate($image, $bgColor["red"], $bgColor["green"], $bgColor["blue"]);
        $image_text = imagecolorallocate($image, $textColor["red"], $textColor["green"], $textColor["blue"]);
        imagestring($image, $options["font"], $options["x"], $options["y"], $this->pass, $image_text);
	imagegif($image); 
}

[MadTechie]

if you use a function to create the image your need to output to an image FILE (then return the file path/name) or call it without outputting ANYTHING else.. (read up on headers for more info)

 

[tiki]

So I must have lets say a blank gif file on the server somewere and output the image functions to that image?

[tiki]

Can someone point me in the right direction for this?

[MadTechie]

Okay lets say i have a script that acts as an image..

 

ie

<?php
header("Content-Type: image/jpeg");
$im  = imagecreatetruecolor(150, 30);
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc  = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
imagestring($im, 1, 5, 5, "This is a image!", $tc);
imagejpeg($im);
?>

 

Loading it up by itself works fine..

 

 

BUT if add

echo "Hello world";

to the start.. (before or after the header) it fails the reason is because the client browser reads the header and expects to get VALID image data and will display it as an image..

 

now, just say i wanted to use a function to create the image

ie

<?php
function DisplayImage()
{
header("Content-Type: image/jpeg");
$im  = imagecreatetruecolor(150, 30);
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc  = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
imagestring($im, 1, 5, 5, "This is a image!", $tc);
imagejpeg($im);
}
?>

 

this is fine..but how are we going to call it ??

remember you can NOT send anything to the browser before hand!

 

one solution may be this

<?php
$test="test.jpg";
DisplayImage($test);
echo "<img src=\"$test\">";

function DisplayImage($file)
{
//header("Content-Type: image/jpeg");
$im  = imagecreatetruecolor(150, 30);
$bgc = imagecolorallocate($im, 255, 255, 255);
$tc  = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 150, 30, $bgc);
imagestring($im, 1, 5, 5, "This is a image!", $tc);
imagejpeg($im,$file);
}
?>

 

NOTE: i commented out the header! as we are creating a file