yii2: Headers already sent error after upgrading to 2.0.14.1
Following fix in #15046: Throw an yii\web\HeadersAlreadySentException if headers were sent before web response (dmirogin). I now cannot process ajax actions
What steps will reproduce the problem?
protected function sendContent($data)
{
$data = 'hello';
\Yii::$app->response->format = \yii\web\Response::FORMAT_JSON;
echo \yii\helpers\Json::encode($data);
Yii::$app->end();
}
What is the expected result?
An Error occurred while handling another error: yii\web\HeadersAlreadySentException: Headers already sent in
What do you get instead?
Output without errors
Additional info
| Q | A |
|---|---|
| Yii version | 2.0.14.1 |
| PHP version | 7.1.8 |
| Operating system | macOS 10.12.6 |
About this issue
- Original URL
- State: closed
- Created 6 years ago
- Reactions: 2
- Comments: 32 (14 by maintainers)
Commits related to this issue
- fix for Yii 2.0.14 see also https://github.com/yiisoft/yii2/issues/15782 — committed to schmunk42/yii2-notification-wrapper by schmunk42 6 years ago
- fix Headers alreay sent Error (#31) with Yii 2.0.14.1 you aren't allowed to echo contents rel yiisoft/yii2#15782 — committed to dpodium/yii2-filemanager by dampfklon 6 years ago
this can be caused by a lot of things. The simplest workaround is probably to enable output buffering in PHP config. As far as I see this is not a problem in Yii, but something in your app that is sending headers before they should be sent.
You can do this, rather than echoing it:
\Yii::$app->response->data = $data;But I still think that throwing a HeadersAlreadySentException is so much extreme. Maybe it will be better to log a Yii::warning. Another option will be to educate people to handle the response properly. Because now it seems impossible to do a echo inside a controller action.
@nikosid use
returnrather than echo.@berosoboy , Thank you. This is working well:
I would rather not enable output buffering due to strict guidelines.
just edit php.ini , set output_buffering = 4096 to output_buffering = On; sed -e ‘s/output_buffering = 4096/output_buffering = On/g’ /etc/php.ini
@AandD what’s the problem to add
exitright afterecho?This should definitely be added to UPGRADE.md. It is breaking change, blowing up existing applications. I know, now I learned I actually had masked header problems, which is good. But I learned it the hard way, after upgrading Yii on production server.
I had the same problem and found this line hidden in a view file:
<?php flush(); ?>I removed the line and the error was gone.@spiro-stathakis , Alternatively you can simply return the data if it is a controller action (I prefer this way):
Understood @samdark . I changed my opinion. I agree with it now. I refactored some old ajax calls that have echo to simply returning content. I think I was programming out of Yii2 pattern 😄
Good work.
@samdark
Thanks. That works. I had uninstalled xdebug when moving to php 7.0 - I seem to remember something about some issues with it - and have been working without it since. Apparently it works fine now. At any rate it’s only on development systems. Sorry for all the posts - but without xdebug or setting php.ini I was having a lot of issues. We have a major Yii1 project moving over to Yii2 along with a lot new api integration, I was getting a little frustrated. Actually my son had xdebug and he was doing fine, ha! It was just me, the old dog… Again, thanks! I’ve been a Yii fan for years now and am very thankful for all you folks’ work.
If it’s a lot, the best way is to configure XDebug.
Simple way to exit is
exit().I had the same issue and this code save me:
The big problem is that I found it in dektrium user too and I can not log inside website.
Now I don’t know if they solved with new version, but other extensions can have the same problem
Is it posiible to make it optional or xdebug error like in development mode? Its very often you need to place echo or var_dump in code not starting debug