How is the display of the 404 error page on VK.com implemented?

J

Jack Daniel's2016-03-30 08:59:06

PHP

Jack Daniel's, 2016-03-30 08:59:06

How is the display of the 404 error page on VK.com implemented?

I will try to formulate the question clearly.
How does VK.com display a 404 error page without a redirect?
It works for them obviously not through htaccess. As far as I understand, first of all, they check through the database whether there is content at such an address. If there is, then we display it, if not, error 404. But when a page with a 404 error is displayed, 8 lines remain from the page code (the same meta tags will not be). How do they "remove" the code of one page while displaying the code of another?
404

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2 answer(s)

Y

Yuri, 2016-03-30
@Yea_intenet

if rendering is done after receiving the data, then there can be no problems.
and if shit like this

<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
<?php 
$data = $db->get();
// .... вывод
?>
</body>
</html>

then only output buffering will help to
run ob_start() before the code starts.
and at the end echo ob_get_clean()
then at any time the displayed content can be reset and start displaying another page
ob_clean();

T

Timur Sergeevich, 2016-03-30
@MyAlesya

You don't need a redirect for this. They just dynamically form and send a page like 404 instead of a regular page.