Restore output buffer in case of exceptions View as Markdown

That is the idea:

<?php

exceptional_ob_start();

echo "Begin\n";
try {
echo "Exception\n";
throw new Exception();
} catch (Exception $e) {}
echo "End\n";

exceptional_ob_end_flush();

?>

And that would be the only output:

Begin
End

Following this logic, we would also need to "unwind" all file descriptors,
database transactions, network connections etc. etc.
This makes no sense.

This makes sense, but it's almost impossible to implement it this way :)

On the other hand, implementing output-buffer the way it is proposed
can actually be possible and it can be really useful

edge-cases are not obvious, though

--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/

Evert | Rooftop wrote:

Generally I make sure that the parts of my code that start an output
buffer are also responsible for closing the output buffer.. so something
like this wouldn't be uncommon in my code..

Agreed. If you'd like to implement transaction support using PHP's
exceptions, you'll need to implement rollback functionality yourself in
the catch block.

--
Edward Z. Yang GnuPG: 0x869C48DA
HTML Purifier http://htmlpurifier.org Anti-XSS Filter
[[ 3FA8 E9A9 7385 B691 A6FC B3CB A933 BE7D 869C 48DA ]]

Generally I make sure that the parts of my code that start an output
buffer are also responsible for closing the output buffer.. so something
like this wouldn't be uncommon in my code..

ob_start();
try {
do_something();
} catch (Exception $e) {
ob_end_clean();
throw $e;
}

$data = ob_get_clean();

Thanks for the answers. I wasn't aware of the fact that ob's could
nest. So one can manually translate the first try-catch to the second:

try {
// ... code
} catch (Exception $e) {
// ... code
}

ob_start();
try {
// ... code
ob_end_flush();
} catch (Exception $e) {
ob_end_clean();
// ... code
}

More verbose, but works.

--
Mehmet