New server ignoring capitalization in PHP app - php

Question

I have worked on a codeigniter 2.1.3 application which was developed on windows running wamp 2.2 (php 5.4.3). I recently uploaded the application to a ubuntu 12.04 server running apache 2.2.22 and php 5.4.6.
My model classes are named like billView.php, categoryModel.php etc. Note the capital letters. The name of the classes inside the php files is also the same. And the name i give when calling the models from controller classes is also the same.
But when I run my app on Ubuntu, I get this error
Unable to locate the model you have specified: billview
The error is thrown from this line:
$this->load->model('billView');
(i.e. php is ignoring the capital letter)
When I rename the model file (only the model filename, class name stays intact) then the error disappears.
How to solve this problem without manually renaming all my files?

Answer 1

From the documentation:
Where Model_name is the name of your class. Class names must have the
first letter capitalized with the rest of the name lowercase. Make
sure your class extends the base Model class.
It's better to follow the naming convention than to work around it.
Hope this helps.

Answer 2

The problem that you are facing is that Windows filesystem (NTFS) is case insensitive, so in windows, billview.php and billView.php are the same file.
On Linux, as you might be guessing now, the typical filesystems (ext2/3/4, xfs, reiserfs...) are case sensitive, and for that reason, billview.php and billView.php are (or may be) different files. In your case, one exists and the other does not.
Inside CodeIgniter autoloader function/method/class/whatever, it is trying to require the file that has the class you are instantiating, so if you tell it that you need the model billview, it will try to require path/to/model/billview.php;, and this file does not exist, so the model doesn't get loaded and then your application fails.
Of course it is recommended to follow a naming convention if there is one as Amal Murali suggests, but it is not the issue here. If all your classes, files, and instances in code had the same capitalization (whether it may be all_lowercase, ALL_UPPERCASE, camelCase or sTuPiD_CaSe) everything would have worked.
So, please refer to your files/class names with the same capitalization as you have created them, and the capitalization in a class name should follow that of the file name it is stored in.
You will have the same problems if your html code refers to files (images, css, js files) in different capitalization for the same reason. The webserver will be looking for image.jpg but it will not exist (the existing file would be Image.JPG for example).
In a related note, variables in php are case sensitive, but functions and classes aren't. despite that, call them always with the right capitalization to avoid problems.

Answer 3

I personally have found this convention in CodeIgniter to make no sense. I wouldn't recommend hacking the CodeIgniter core but you can easily extend the CI_Loader class. Here is mine from CI version 2.2.0.
<?php
class MY_Loader extends CI_Loader
{
/**
* Model Loader
*
* This function lets users load and instantiate models.
*
* #param string the name of the class
* #param string name for the model
* #param bool database connection
* #return void
*/
public function model($model, $name = '', $db_conn = FALSE)
{
if (is_array($model))
{
foreach ($model as $babe)
{
$this->model($babe);
}
return;
}
if ($model == '')
{
return;
}
$path = '';
// Is the model in a sub-folder? If so, parse out the filename and path.
if (($last_slash = strrpos($model, '/')) !== FALSE)
{
// The path is in front of the last slash
$path = substr($model, 0, $last_slash + 1);
// And the model name behind it
$model = substr($model, $last_slash + 1);
}
if ($name == '')
{
$name = $model;
}
if (in_array($name, $this->_ci_models, TRUE))
{
return;
}
$CI =& get_instance();
if (isset($CI->$name))
{
show_error('The model name you are loading is the name of a resource that is already being used: '.$name);
}
//$model = strtolower($model);
foreach ($this->_ci_model_paths as $mod_path)
{
if ( ! file_exists($mod_path.'models/'.$path.$model.'.php'))
{
continue;
}
if ($db_conn !== FALSE AND ! class_exists('CI_DB'))
{
if ($db_conn === TRUE)
{
$db_conn = '';
}
$CI->load->database($db_conn, FALSE, TRUE);
}
if ( ! class_exists('CI_Model'))
{
load_class('Model', 'core');
}
require_once($mod_path.'models/'.$path.$model.'.php');
//$model = ucfirst($model);
$CI->$name = new $model();
$this->_ci_models[] = $name;
return;
}
// couldn't find the model
show_error('Unable to locate the model you have specified: '.$model);
}
}
?>
All I did was copy the the CI_Loader::model method then comment out these two lines
//$model = strtolower($model);
//$model = ucfirst($model);
All you have to do is put the above class in your application/core/ folder and it should work.