Two (almost) identical pieces of code produce separate results - php

Question

I have been working on a little MVC project to assist in my self-learning and I have come across an issue that completely baffled me. I made a blog section in this MVC-ish system and pulled user permissions from an ACL with no problem whatsoever.
I moved onto creating a member section and as soon as i added any permissions checking I get the following error from Chrome:
No data received
Unable to load the web page because the server sent no data.
Here are some suggestions:
Reload this web page later.
Error 324 (net::ERR_EMPTY_RESPONSE): The server closed the connection without sending any data.
I thought it was weird, so I double checked my error logs and nothing had shown up. So I decided to copy and paste the working blog code into the member file, reloaded and i got the EXACT same error, the only difference between the two files right now is the file name and the class name.
Here is the Blog code:
<?php
class blog extends frontController {
public $model;
public $user;
public function __construct()
{
parent::__construct();
$this->model = $this->autoload_model();
$this->user = $this->load_user();
$this->user->getUserRoles();
}
public function index()
{
//Will only list the latest post ;)
if(!$this->user->hasPermission('blog_access'))
{
$array = $this->model->list_posts();
if(empty($array))
{
$this->variables(array(
'site_title' => 'View Blog Posts',
'post_title' => 'Sorry but there are no posts to display'
));
} else {
$this->variables(array(
'site_title' => 'View Blog Posts',
'list' => $array[0],
'post_title' => $array[0]['entry_title'],
'link' => str_replace(' ', '_',$array[0]['entry_title']),
));
}
} else {
$this->variables(array(
'site_title' => 'Error :: Design Develop Realize',
'body' => 'Sorry, but you do not have permission to access this',
));
}
$this->parse('blog/list', $this->toParse);
}
This is the member file:
<?php
class member extends frontController {
public $model;
public $user;
public function __construct()
{
parent::__construct();
$this->model = $this->autoload_model();
$this->user = $this->load_user();
$this->user->getUserRoles();
}
public function index()
{
//Will only list the latest post ;)
if(!$this->user->hasPermission('blog_access'))
{
//$array = $this->model->list_posts();
if(empty($array))
{
$this->variables(array(
'site_title' => 'Design Develop Realize :: View Blog Posts',
'post_title' => 'Sorry but there are no posts to display'
));
} else {
$this->variables(array(
'site_title' => 'Design Develop Realize :: View Blog Posts',
'list' => $array[0],
'post_title' => $array[0]['entry_title'],
'link' => str_replace(' ', '_',$array[0]['entry_title']),
));
}
} else {
$this->variables(array(
'site_title' => 'Error :: Design Develop Realize',
'body' => 'Sorry, but you do not have permission to access this',
));
}
$this->parse('blog/list', $this->toParse);
}
In the member class, if I comment out $this->user = $this->load_user(); then the error disappears!!!
Just for reference here is that function:
protected function load_user()
{
if(!$this->loader->loaded['acl'])
{
$this->loader->loadCore('acl');
}
return $this->loader->loaded['acl'];
}
Any help or suggestions would be appreciated as I am stumped!
PS yes I do have error reporting set to cover everything and no it does not log anything!
EDIT: Because all files go through index.php I have placed the error reporting there:
<?php
error_reporting(E_ALL);
ini_set('date.timezone', "Europe/London");
require_once('system/library/loader.php');
$loader = new loader();
$loader->loadCore(array('frontController', 'routing'));
EDIT 2: loadCore() is below
public function loadCore($toLoad, $params = false)
{
//important task first, check if it is more then 1 or not
if(is_array($toLoad))
{
//more then one so lets go to the task!
foreach($toLoad as $file)
{
if(file_exists('system/library/' . $file . '.php'))
{
require_once('system/library/' . $file . '.php');
if($params)
{
$this->loaded[$file] = new $file($params);
} else {
$this->loaded[$file] = new $file;
}
} else {
trigger_error("Core File $file does not exist");
}
}
} else {
//Phew, less work, it is only one!
if(file_exists('system/library/' . $toLoad . '.php'))
{
require_once('system/library/' . $toLoad . '.php');
if($params)
{
echo(__LINE__); exit;
$this->loaded[$toLoad] = new $toLoad($params);
} else {
$this->loaded[$toLoad] = new $toLoad;
}
}
}
}
Update: I modified loadCore so that if it was the acl being called it would use a try...catch() and that has not helped as it will not display an error just the same chrome and IE pages
Update 2: I have spoken with my host and it seems that everytime this error occurs, apache logs the following (not sure why I cannot see it in my copy of the logs!)
[Wed Feb 22 08:07:11 2012] [error] [client 93.97.245.13] Premature end
of script headers: index.php

Answer 1

You have commented out
//$array = $this->model->list_posts();
So now array is null and you are trying to use
'list' => $array[0],
'post_title' => $array[0]['entry_title'],
which definitely will generate an error.
EDIT:-
I see you have
'body' => 'Sorry, but you do not have permission to access this' , )); }
That is in second else which is a syntax error. and generates an output. If you have enabled, compress output in CI, that will cause this error.

Answer 2

"Premature end of script headers" are internal server errors. Which generally occurs when script breaks and does not send any HTTP headers before send the error messages. There might be several causes to this.
One might be output buffering. May be the server you are using buffers the output by default. I will suggest turning off the output_buffering using output_buffering = off on php.ini [docs here].
Make sure you are sending correct HTTP headers also
print "Content-type: text/html\n\n";
There are few more suggestion on this link.
To learn more about this error, go here.
Hope it helps

Answer 3

I'd be interested in seeing what's inside the loadCore function.
Have you used error_log anywhere? It might help shed some light on the issue.

Answer 4

Have you tested this page in different browsers? Googled your error, and it's indicating that it may be chrome specific?
Your statement that commenting out the loadCore('acl') is interesting, so obviously I would start there. You're sure that it is getting the system/library/acl.php page via the loader? Aka, it is triggering that line 2 below the exit in loadCore()? var_dump the return imo to make sure you're getting the object.

Answer 5

First of all. This error is produced when your server disconnect before it send any data.
A few suggestions.
your code is broken and let crash the application
your error logging should be enhanced by NOTICES
write tests to check every part
u should enable and use a debugger (zend_debugger, xdebug)
post a few more connection infos (e.g. wget -O - --debug 'url')
There is/was a special chrome issue for that problem
http://www.google.pl/support/forum/p/Chrome/thread?tid=3aa7b40eb01a95c8&hl=en#fid_3aa7b40eb01a95c80004ae797939c267

Answer 6

I suggest checking whether there are any blank lines before the tags.
What file names are you using?, are there any conventions you have to follow to fit a framework you might be using?

Answer 7

I wonder if this is a server problem and not a code problem?
This thread suggests that the server error you are seeing (500 premature end to headers) could be the result of Apache logs that are too full and need to be rotated. However it really could be anything - it seems to suggest simply that the script returns no output at all to the browser.
The other thing I'd check is file permissions, and the functioning of the include_once and file_exists in the loadCore method, as that looks the likeliest area to cause problems that might stop the script without even throwing a php error.

Answer 8

Maybe it´s a character/encoding error, open both files with notepad++ , goto Encoding, then select Convert to UTF-8, save the file and test it again.
Good Luck!