Question

In a small application, I’m writing, during installation phase, the user must enter detail about the MySQL connection in a form (server name, database name, username …)

I would like to display line by line the result of tests and actions done in a window, with eventually a small pause between each test, like :

“Connection to the server …”(2s) “ok” (2s)
“Connection to the database …”(2s) “ok” (2s)
“Creation of tables …”(2s) “ok”
….etc

I have tried with ob_start(), flush(), ob_flush() but it doesn’t work as my webserver seems to buffer itself the php output, so the script takes a long time to run but everything is printed at the same time.

I have searched here and with Google, without any result (may be not with the correct keywords)

Can you point me to solution ?
with Ajax may be ?

ericc

Answer 1

There are multiple solutions to this, but disabling caching altogether isn’t easily accomplished.
Because on the server side there is some caching, which can be disabled, but there is also a very large chance that the browser is caching as well.

To fix this you have a few options:

• fake it, display a static javascript based “animation” and redirect when done.

• Use ajax, let the installation script echo the results to a text file / mysql database and use a different php script to load the the text file / database at set intervals and display the new results.

• Use the newest HTML5/javascript streaming API which is made exactly for stuff like this, it is, however, quite hard to find any good documentation on this.

To disable server side caching, I use this code:

@ini_set('zlib.output_compression', 0);
@ini_set('implicit_flush', 1);
for ($i = 0; $i < ob_get_level(); $i++) { ob_end_flush(); }
ob_implicit_flush(1);
header('Expires: Fri, 01 Jan 1990 00:00:00 GMT');
header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate');
header('Pragma: no-cache');
header('Connection: close');