list folders where Codeigniter searches for classes - php

Question

Codeigniter does not find trivial classes:
Unable to load the requested class: Bcrypt
But the same goes for custom made classes defined in files in application/libraries/. I am used that django lists the folders where it searched for a file, but did not find one. Obviously CI must also iterate over some list of folders or files, but is not as polite to display them along with the error.
It seems as if CI has a naming convention to deduce the (set of) filename(s) where it would expect a class to be. How can I programmatically error_log the list of folders or filenames that Codeigniter or PHP tried to track down this class?
EDIT: The lines of code that produce such a loading-error are:
$autoload['libraries'] = array('database','session','mi_file_fetcher');
in application/config/autoload.php and
$this->load->library("bcrypt");
in application/models/User.php
As stated in the comments, I was not asking for a fix, I was asking for a list.

Answer 1

I managed to do so by updating system/core/Loader.php
protected function _ci_load_library_files_tried($class, $subdir, $params, $object_name)
{
$files_tried = array(BASEPATH . 'libraries/' . $subdir . $class . '.php');
foreach ($this->_ci_library_paths as $path) {
if ($path === BASEPATH) {
continue;
}
array_push($files_tried, $path . 'libraries/' . $subdir . $class . '.php');
}
return $files_tried;
}
protected function _ci_load_library($class, $params = NULL, $object_name = NULL)
{
// ...
// If we got this far we were unable to find the requested class.
$files_tried = $this->_ci_load_library_files_tried($class, $subdir, $params, $object_name);
log_message('error', 'Unable to load the requested class: '.$class .
", tried these files:\n" . join("\n", $files_tried));
show_error('Unable to load the requested class: '.$class .
', tried these files:<ul><li>' . join('</li><li>', $files_tried) . '</li></ul>');
}
Would be great if CI actually provided decent debugging information.

Answer 2

The CodeIgniter (CI) documentation does tell you the default locations of libraries, models, helpers, views and many other framework objects. There isn't a section that explicitly lists the folders though. The Loader Class documentation does tell you, but you have to dig for it a bit.
The subtopics on the General Topics section of the docs clearly state the default locations for the various classes the frameworks uses and where to put custom classes.
In most cases following the prescribed file structure and using the loader class, e.g. (Bcrypt.php is in /application/libraries/)
$this->load->library('bcrypt');
works perfectly.
There are cases (none of which seem to be involved in your problem) where CI needs help. Rather than hack or extend CI_Loader an autoloader is useful in these cases.
There are lots of ways to add an autoloader but my preference is to use CI's Hooks feature. Here's how.
In config.php set 'enable_hooks' to TRUE
$config['enable_hooks'] = TRUE;
These lines go in /application/config/hooks.php
$hook['pre_system'][] = array(
'class' => '',
'function' => 'register_autoloader',
'filename' => 'Auto_load.php',
'filepath' => 'hooks'
);
The following is the contents of /application/hooks/Auto_load.php
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
function register_autoloader()
{
spl_autoload_register('my_autoloader');
}
/**
* Allows classes that do not start with CI_ and that are
* stored in these subdirectories of `APPPATH`
* (default APPPATH = "application/" and is defined in "index.php")
* libraries,
* models,
* core
* controllers
* to be instantiated when needed.
* #param string $class Class name to check for
* #return void
*/
function my_autoloader($class)
{
if(strpos($class, 'CI_') !== 0)
{
if(file_exists($file = APPPATH.'libraries/'.$class.'.php'))
{
require_once $file;
}
elseif(file_exists($file = APPPATH.'models/'.$class.'.php'))
{
require_once $file;
}
elseif(file_exists($file = APPPATH.'core/'.$class.'.php'))
{
require_once $file;
}
elseif(file_exists($file = APPPATH.'controllers/'.$class.'.php'))
{
require_once $file;
}
}
}
The function log_message($level, $message) could be used in the above if you wanted.
If you are using some other creative folder structure you will have to modify the above to accommodate that layout.