ob_get_clean, only works twice

Question

Take this simple script:

ob_start();
$text = array();

echo 'first text';
$text[] = ob_get_clean();

echo 'second text';
$text[] = ob_get_clean();

echo 'third text';
$text[] = ob_get_clean();

echo 'fourth text';
$text[] = ob_get_clean();

print_r($text);

This outputs:

third textfourth textArray
(
    [0] => first text
    [1] => second text
    [2] => 
    [3] => 
)

But I would expect:

Array
(
    [0] => first text
    [1] => second text
    [2] => third text
    [3] => fourth text
)

PHPFiddle

When I try it I only get first text in the array. Seems like ob_get_clean has very inconsistent results — StephenTG, Jul 23 '13 at 15:02
@StephenTG I see what you mean. PHPFiddle works twice: http://phpfiddle.org/lite/code/u4z-us5 but http://phpcodepad.com/ only works once — Drahcir, Jul 23 '13 at 15:03

score 8 · Accepted Answer · edited Jul 14 '23 at 22:37

To do this correctly you should be doing ob_start() after ob_get_clean() because ob_get_clean() gets the current buffer contents and delete the current output buffer.

<?php
ob_start();
$text = array();

echo 'first text';
$text[] = ob_get_clean();
ob_start();

echo 'second text';
$text[] = ob_get_clean();

ob_start();

echo 'third text';
$text[] = ob_get_clean();

ob_start();

echo 'fourth text';
$text[] = ob_get_clean();

print_r($text);
?>

score 5 · Answer 2 · answered Jul 23 '13 at 15:02

You need to call ob_start() again every time before calling ob_get_clean().

ob_start();
$text = array();

echo 'first text';
$text[] = ob_get_clean();

ob_start();
echo 'second text';
$text[] = ob_get_clean();

ob_start();
echo 'third text';
$text[] = ob_get_clean();

ob_start();
echo 'fourth text';
$text[] = ob_get_clean();

print_r($text);

score 4 · Answer 3 · answered Jul 23 '13 at 15:03

4

ob_get_clean turns off output buffering. It should really only give you the 1st one. It's showing two because you have a 2nd layer of output buffering active.

Try using:

$text[] = ob_get_contents();
ob_clean();

answered Jul 23 '13 at 15:03

gen_Eric

223,194
41
299
337

score 4 · Answer 4 · answered Jul 23 '13 at 15:07

4

From php.org:

ob_get_clean() essentially executes both ob_get_contents() and ob_end_clean().

ob_get_clean()

When ob_end_clean() is called, it turns off buffering. You need to call ob_get_start() again, to turn buffering back on.

answered Jul 23 '13 at 15:07

mvanlamz

91
1
3

ob_get_clean, only works twice

4 Answers4