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V1.5 - Output buffer error when loading a view with an error in another view
 
hlz
Posted: 03 November 2006 05:31 AM   [ Ignore ]  
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I stumbled upon the following possible bug. When I load a view which contains an error in another view (the dirty way :P), then something screws up the output buffering. I have constructed and added a testcase below.

Controller: ViewBug.php

<?php

if(!defined('BASEPATH')) exit('No direct script access allowed');

/******************************************************************************
* ViewBug
******************************************************************************/

class ViewBug extends Controller
{
    function ViewBug()
    {
        parent::Controller();
    }
    
    /*
        triggers OB error in Loader.php
    */
    function test1()
    {        
        $this->load->view('viewbug.test1.view.php');
    }
    
    /*
        works correct
    */
    function test2()
    {
        $viewdata = array(
                        
            'view_with_error' => $this->load->view('viewbug.errorview.view.php', null, true)
        );
        
        $this->load->view('viewbug.test2.view.php', $viewdata);        
    }
}
?>

View 1: viewbug.test1.view.php

<h1>viewbug.test1.view.php</h1>

<?
echo $this->load->view('viewbug.errorview.view.php', null, true);
// or
// $this->load->view('viewbug.errorview.view.php');
?>

View 2: viewbug.test2.view.php

<h1>viewbug.test2.view.php</h1>

<?
echo $view_with_error;
?>

Error view: viewbug.errorview.view.php

<h1>viewbug.errorview.view.php</h1>
<? a; ?>

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Rick Ellis
Posted: 03 November 2006 12:38 PM   [ Ignore ]   [ # 1 ]  
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Your code works perfectly for me on PHP 5.1, 4.3, and 4.4.0.  No errors.

Looking at the code I’m not seeing how there can be a buffer error since each view load causes ob_start() to be called.  I wonder if your version of PHP has a bug? 

The error you are getting is just a notice, not a fatal error, so you might just suppress output buffering errors in the Loader.php class.  If you look in that file you’ll find two places where ob_end_clean() is being called.  Change them to @ob_end_clean()

Unless I’m missing some other component in your code somewhere, I’m simply not finding an error.  Sorry…

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JesseJr
Posted: 03 November 2006 01:48 PM   [ Ignore ]   [ # 2 ]  
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I have similar problem. My configuration: PHP 5.1.6 - Xampp for Linux 1.5.4.

Note <? a; ?> in viewbug.errorview.view.php. If variable exists, this problem not occour.

Thanks a lot.

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Jessé Jr
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hlz
Posted: 04 November 2006 01:11 PM   [ Ignore ]   [ # 3 ]  
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When running test1 i get the following errors:

A PHP Error was encountered.

Severity: Notice

Message: Use of undefined constant a - assumed 'a'

Filename: _test/viewbug.errorview.view.php

Line Number: 2

A PHP Error was encountered.

Severity: Notice

Message: ob_end_clean() [ref.outcontrol]: failed to delete buffer. No buffer to delete.

Filename: libraries/Loader.php

Line Number: 648

The first error is correct. The second is not supposed to be there. I know it’s nothing fancy, but there is something wrong with how the loader handles output buffering in combination with PHP errors.

JesseJr - 03 November 2006 01:48 PM

I have similar problem. My configuration: PHP 5.1.6 - Xampp for Linux 1.5.4.

Note <? a; ?> in viewbug.errorview.view.php. If variable exists, this problem not occour.

Thanks a lot.

That “a;” is placed for the purpose of triggering an error.
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hlz
Posted: 04 November 2006 01:19 PM   [ Ignore ]   [ # 4 ]  
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If i use this view with test1:

<h1>viewbug.test1.view.php</h1>

<?
$this->load->view('_test/viewbug.errorview.view.php');
?>

Then there is only the outputbuffer error. There is no way of finding what causes the original error on what line.

So, it’s minor, but worth to mention IMO.
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ioptics
Posted: 07 November 2006 06:21 AM   [ Ignore ]   [ # 5 ]  
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I have just encountered this bug and in my case it appeared when I tried to call an undefined validator error message, like so:

<?php print $this->validation->description_error;?>

Adding the field to $this->validation->set_fields(); solved the problem.

I don’t think this is expected behaviour.
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hlz
Posted: 07 November 2006 07:33 AM   [ Ignore ]   [ # 6 ]  
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Yep, this ‘bug’ can be triggered in several ways.
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JesseJr
Posted: 07 November 2006 09:03 PM   [ Ignore ]   [ # 7 ]  
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hlz,

is your compress output option in config\config.php file enabled or disabled?

Jessé Jr

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Jessé Jr
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hlz
Posted: 08 November 2006 03:50 AM   [ Ignore ]   [ # 8 ]  
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JesseJr - 07 November 2006 09:03 PM

hlz,

is your compress output option in config\config.php file enabled or disabled?

Jessé Jr

It is disabled.
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CI Phoebe
Posted: 15 November 2006 06:44 AM   [ Ignore ]   [ # 9 ]  
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This has me total confused.

Here is a view:

<?php
$this->load->view('page_header',$headers);
$this->load->view('banner');
?>

<div id=content>
<h1>How am I doing?</h1>
</div>  <!-- content -->

<?php
$this->load->view('page_footer');
?>

page_header has an undeclared variable error in it.

If I run it as is then the How Am I Doing appears, but no page_header, banner or page_footer and at the bottom of the page I get

A PHP Error was encountered

Severity: Notice

Message: ob_end_clean() [ref.outcontrol]: failed to delete buffer. No buffer to delete.

Filename: libraries/Loader.php

Line Number: 648

If I look at the debug log I see the original error and each of the views being loaded

ERROR - 2006-11-15 11:36:12 --> Severity: Notice Notice --> Undefined variable: js /Users/phoebebr/Sites/ci151/system/application/views/page_header.php 28
ERROR - 2006-11-15 11:36:12 --> Severity: Notice Notice --> Undefined variable: js /Users/phoebebr/Sites/ci151/system/application/views/page_header.php 29
DEBUG - 2006-11-15 11:36:12 --> File loaded: /Users/phoebebr/Sites/ci151/system/application/views/page_header.php
DEBUG - 2006-11-15 11:36:12 --> File loaded: /Users/phoebebr/Sites/ci151/system/application/views/banner.php
DEBUG - 2006-11-15 11:36:12 --> File loaded: /Users/phoebebr/Sites/ci151/system/application/views/page_footer.php
DEBUG - 2006-11-15 11:36:12 --> File loaded: /Users/phoebebr/Sites/ci151/system/application/views/home.php
ERROR - 2006-11-15 11:36:12 --> Severity: Notice Notice --> ob_end_clean() [<a href='ref.outcontrol'>ref.outcontrol</a>]: failed to delete buffer. No buffer to delete. /Users/phoebebr/Sites/ci151/system/libraries/Loader.php 648
DEBUG - 2006-11-15 11:36:12 --> Final output sent to browser
DEBUG - 2006-11-15 11:36:12 --> Total execution time: 0.0710

Here is where it gets strange.  If I put an echo statement in Loader just above the logging code and comment out the buffers like this:

//    ob_start();
                
        // If the PHP installation does not support short tags we'll
        // do a little string replacement, changing the short tags
        // to standard PHP echo statements.
        if ((bool) @ini_get('short_open_tag') === FALSE AND config_item('rewrite_short_tags') == TRUE)
        {
            echo eval('?>'.preg_replace("/;*\s*\?>/", "; ?>", str_replace('<?=', '<?php echo ', file_get_contents($path))).'<?php ');
        }
        else
        {
            include($path);
        }
        
        echo '['.$path.']';
        log_message('debug', 'File loaded: '.$path);
        
        // Return the file data if requested
        if ($return === TRUE)
        {        
    //        $buffer = ob_get_contents();
//            ob_end_clean();
            
            return $buffer;
        }

I see the banner and page_footer views being loaded BUT NOT page_header

However, if I alter my view to call page_header twice

<?php
$this->load->view('page_header',$headers);
$this->load->view('page_header',$headers);
     
$this->load->view('banner');

?>


I see the page_header view being loaded and the errors are correctly reported.

page_header
A PHP Error was encountered

Severity: Notice

Message: Undefined variable: js

Filename: views/page_header.php

Line Number: 28

A PHP Error was encountered

Severity: Notice

Message: Undefined variable: js

Filename: views/page_header.php

Line Number: 29

[/Users/phoebebr/Sites/ci151/system/application/views/page_header.php]


This is getting too deep for me!!!!
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Martin Hall
Posted: 15 November 2006 01:30 PM   [ Ignore ]   [ # 10 ]  
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Phoebe - 15 November 2006 06:44 AM

This is getting too deep for me!!!!

Phoebe, you’re not alone! There have been a number of “php errors not being reported” posts, including my own.
In my own experience, I could spot my error pretty quickly and it was usually one or more undefined variables in a view.
Whether this is a CI or a PHP bug, I have no idea. But there does appear to be a connection between “bad” CI views and the failure to display any php error message.
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David_CSD
Posted: 15 November 2006 06:20 PM   [ Ignore ]   [ # 11 ]  
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Mark me down as experiencing this as well. I am having this occur on my development server which uses PHP 5.1.6 & Apache/1.3.37. I am using CI 1.5.0.1.

What is weird is that sometimes it is totally blank, and sometimes I get the output buffer error described in the first post.
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Martin Hall
Posted: 16 November 2006 06:46 AM   [ Ignore ]   [ # 12 ]  
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Commenting out the ob_end_clean() call towards the end of show_php_error() in Exceptions.php seems to fix this for me.
Obviously this may create new problems elsewhere, though. I’m only looking at one particular scenario at the moment: bad or missing variable in a view file. Output buffering gurus required from here on….
UPDATE: On the other hand, ob_end_clean() was in 1.4.1 with no problem (for me, anyway). Which brings me back to the lines which were new to show_php_error() in 1.5 :

if (ob_get_level() > 1)
        {
            ob_end_flush();    
        }


Rick has previously told me that these lines were added to fix another problem, although I can’t remember what it was.
Commenting out the ob_end_flush() call fixes my problem; also I found this in php help which looks significant:

User contributed notes:
(18-May-2005 04:45)

Sometimes, ob_get_level() may be off by 1 because at the start of the script, it will return 1 even if ob_start() has never been called (and clearing the output buffer via ob_end_clean() and the like can be done without error).  As a result, the first ob_start() will have an ob_get_level() of 2, the second will be 3, and so on.
I’m not sure if this is a PHP 5 thing or possibly because our server is set to gzip all html documents.

I’m developing on php 5.0.4.
I think the ob_get_level() call needs a re-think. Better people than me, apply now.
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Rick Ellis
Posted: 19 November 2006 02:33 PM   [ Ignore ]   [ # 13 ]  
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I think I have a solution, but since I’m unable to duplicate the problem locally I would appreciate it very much if you guys can test it for me.  Here’s the proposed fix:


Open:  libraries/Exceptions.php

In the constructor, add this:

$this->ob_level = ob_get_level();

Your constructor will now look like this:

function CI_Exceptions()
{
    $this->ob_level = ob_get_level();
}


Next, at lines 120 AND 156 change this:

if (ob_get_level() > 1)
{
    ob_end_flush();    
}

To this:

if (ob_get_level() > $this->ob_level + 1)
{
    ob_end_flush();    
}

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CI Phoebe
Posted: 19 November 2006 03:08 PM   [ Ignore ]   [ # 14 ]  
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Yes!

That fixed it for me.

kiss
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Martin Hall
Posted: 19 November 2006 03:39 PM   [ Ignore ]   [ # 15 ]  
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Looks good to me, too. (Ellismania suddenly erupts! Cue singing, dancing, drinking, er, more drinking…)
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