PHP and JavaScript: Reload captcha image
Question
I've made my own captcha class in PHP, just to learn. It's ok, working as I want. I've tried to add a "refresh image" button but I don't know how do I do that.
form code:
<p><img src="img.php" alt="Captcha!" /></p>
img.php code:
<?php
require_once 'captcha.class.php';
$captcha = Captcha::instance(10);
echo $captcha;
?>
__toString method:
public function __toString()
{
ob_start();
header('Content-Type: image/jpeg');
imagejpeg($this->drawImage(), null, 100);
return ob_get_flush();
}
These code will output the captcha. How could I refresh this image? Something in AJAX would be great! Thank you.
3 answers
solution1
0 2011-02-08 15:50:03
您能否让重新加载对创建新验证码的页面进行AJAX调用，然后将新创建的结果返回到DIV中？
solution2
0 2011-02-08 15:59:24
<html>
<head>
<script type="text/javascript">
function reload()
{
var img = new Image();
img.src = 'img.php';
var x = document.getElementById('captcha');
x.src = img.src;
}
</script>
</head>
<body>
<a href="javascript: reload()" >Reload</a>
<img src="img.php" alt="Captcha!" id="captcha" />
</body>
</html>
Maybe a plain x.src = 'img.php' would do the trick but just to be shure it get's a new request i've made it using another image ( it allso gives you a bit more to search/learn ) .
solution3
0 ACCPTED 2011-02-08 16:02:51
How are you checking the captcha is correct when the form is completed? Session variable?
If it is a single session variable, you could just refresh the image using plain javascript. Adding a random query string to the end of the image url would avoid any caching issues.
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