Question

If you have a live website (using PHP,MySQL,JS,CSS) and say you change some functionality. What is the best way to make sure, that when a user visits the site, the changed pages are updated and not loaded from cache?

Answer 1

For that reson there is file loaders made for. When you load css, js or any other file, you must set cache control header. You can do it by editing .htaccess or with php.

.htaccess demo

<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault A300
ExpiresByType image/x-icon A2592000
ExpiresByType application/x-javascript A3600
ExpiresByType text/css A3600
ExpiresByType image/gif A604800
ExpiresByType image/png A604800
ExpiresByType image/jpeg A604800
ExpiresByType text/plain A300
ExpiresByType application/x-shockwave-flash A604800
ExpiresByType video/x-flv A604800
ExpiresByType application/pdf A604800
ExpiresByType text/html A300
</IfModule>

PHP demo:

 $offset = 3600 * 24;
 $expire = "Expires: " . gmdate("D, d M Y H:i:s", time() + $offset) . " GMT";
 header($expire);