Challenging Issue : Loading models from external directory in Code Igniter - php

Question

I have been trying to figure out a way to load models from different directory other than "application/models" directory.
I want to load my model from "application/modules".
I have tried the instructions by extending CI_Loader by following instructions provided in
http://ellislab.com/forums/viewthread/103276/#
but it is giving me error "Unable to locate the specified class: Model.php" whereas my core "Model.php" is there under "system/core" folder.
Even ,I have also tried to load model using
$this->load->model (APPPATH.'modules/mymodel.php');
but no success.
UPDATE:
I want my model loader to behave like this :
$this->load->module('mymodel')
and
$this->mymodel->mymodelmethod() !!
NOT like: $this->load->models('mymodel')
Is there any way i could load models from outside the "application/modules" folder ?
Please advise .Thanks

Answer 1

The problem is that the code you reference is for an older version of codeigniter. In older versions of codeigniter the CI_Model class was named Model. As the class Model doesn't exist in the latest version of php you are getting the error:
Unable to locate the specified class: Model.php
The part of the code where this is happening is towards the end (line 114):
if ( ! class_exists('Model'))
{
load_class('Model', FALSE);
}
If you check your system/core/Loader.php you will see that in the version of codeigniter you are using this has been replaced with:
if ( ! class_exists('CI_Model'))
{
load_class('Model', 'core');
}
You need to re-write the MY_Loader.php to make it compatible with the version of codeigniter you are using, presumably 2.1.
The best way to do this would be to grab the Codeigniter 2.1 version of the core Loader.php and use the model() method from it as a base for re-writing your MY_Loader.php.
Something to bare in mind when re-writing your MY_Loader.php is that constructors also changed in later versions of codeigniter, so your MY_Loader class should look something like this:
class MY_Loader extends CI_Loader {
function __construct()
{
parent::__construct();
}
public function model($model, $name = '', $db_conn = FALSE)
{
...
}
}
More details on extending core classes can be found in the Codeigniter Documentation
UPDATE
I noticed you changed your functionality, so I updated the answer. You can create a whole new loader and base it off the core CI_Model class, although it seems like a lot of effort when you could just extend the model loader and be done.
class MY_Loader extends CI_Loader {
protected $_ci_module_paths = array();
protected $_ci_modules = array();
function __construct()
{
parent::__construct();
$this->_ci_module_paths = array(APPPATH);
}
public function initialize()
{
$this->_ci_classes = array();
$this->_ci_loaded_files = array();
$this->_ci_models = array();
$this->_ci_modules = array();
$this->_base_classes =& is_loaded();
$this->_ci_autoloader();
return $this;
}
public function module($module, $name = '', $db_conn = FALSE)
{
if (is_array($module))
{
foreach ($module as $babe)
{
$this->$module($babe);
}
return;
}
if ($module == '')
{
return;
}
$path = '';
// Is the $module in a sub-folder? If so, parse out the filename and path.
if (($last_slash = strrpos($module, '/')) !== FALSE)
{
// The path is in front of the last slash
$path = substr($module, 0, $last_slash + 1);
// And the module name behind it
$module = substr($module, $last_slash + 1);
}
if ($name == '')
{
$name = $module;
}
if (in_array($name, $this->_ci_modules, TRUE))
{
return;
}
$CI =& get_instance();
if (isset($CI->$name))
{
show_error('The module name you are loading is the name of a resource that is already being used: '.$name);
}
$module = strtolower($module);
foreach ($this->_ci_module_paths as $mod_path)
{
if ( ! file_exists($mod_path.'modules/'.$path.$module.'.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($mod_path.'modules/'.$path.$module.'.php');
$module = ucfirst($module);
$CI->$name = new $module();
$this->_ci_modules[] = $name;
return;
}
// couldn't find the model
show_error('Unable to locate the module you have specified: '.$module);
}
public function add_package_path($path, $view_cascade=TRUE)
{
$path = rtrim($path, '/').'/';
array_unshift($this->_ci_library_paths, $path);
array_unshift($this->_ci_model_paths, $path);
array_unshift($this->_ci_module_paths, $path);
array_unshift($this->_ci_helper_paths, $path);
$this->_ci_view_paths = array($path.'views/' => $view_cascade) + $this->_ci_view_paths;
// Add config file path
$config =& $this->_ci_get_component('config');
array_unshift($config->_config_paths, $path);
}
public function remove_package_path($path = '', $remove_config_path = TRUE)
{
$config =& $this->_ci_get_component('config');
if ($path == '')
{
$void = array_shift($this->_ci_library_paths);
$void = array_shift($this->_ci_model_paths);
$void = array_shift($this->_ci_module_paths);
$void = array_shift($this->_ci_helper_paths);
$void = array_shift($this->_ci_view_paths);
$void = array_shift($config->_config_paths);
}
else
{
$path = rtrim($path, '/').'/';
foreach (array('_ci_library_paths', '_ci_model_paths', '_ci_module_paths', '_ci_helper_paths') as $var)
{
if (($key = array_search($path, $this->{$var})) !== FALSE)
{
unset($this->{$var}[$key]);
}
}
if (isset($this->_ci_view_paths[$path.'views/']))
{
unset($this->_ci_view_paths[$path.'views/']);
}
if (($key = array_search($path, $config->_config_paths)) !== FALSE)
{
unset($config->_config_paths[$key]);
}
}
// make sure the application default paths are still in the array
$this->_ci_library_paths = array_unique(array_merge($this->_ci_library_paths, array(APPPATH, BASEPATH)));
$this->_ci_helper_paths = array_unique(array_merge($this->_ci_helper_paths, array(APPPATH, BASEPATH)));
$this->_ci_model_paths = array_unique(array_merge($this->_ci_model_paths, array(APPPATH)));
$this->_ci_module_paths = array_unique(array_merge($this->_ci_module_paths, array(APPPATH)));
$this->_ci_view_paths = array_merge($this->_ci_view_paths, array(APPPATH.'views/' => TRUE));
$config->_config_paths = array_unique(array_merge($config->_config_paths, array(APPPATH)));
}
private function _ci_autoloader()
{
if (defined('ENVIRONMENT') AND file_exists(APPPATH.'config/'.ENVIRONMENT.'/autoload.php'))
{
include(APPPATH.'config/'.ENVIRONMENT.'/autoload.php');
}
else
{
include(APPPATH.'config/autoload.php');
}
if ( ! isset($autoload))
{
return FALSE;
}
// Autoload packages
if (isset($autoload['packages']))
{
foreach ($autoload['packages'] as $package_path)
{
$this->add_package_path($package_path);
}
}
// Load any custom config file
if (count($autoload['config']) > 0)
{
$CI =& get_instance();
foreach ($autoload['config'] as $key => $val)
{
$CI->config->load($val);
}
}
// Autoload helpers and languages
foreach (array('helper', 'language') as $type)
{
if (isset($autoload[$type]) AND count($autoload[$type]) > 0)
{
$this->$type($autoload[$type]);
}
}
// A little tweak to remain backward compatible
// The $autoload['core'] item was deprecated
if ( ! isset($autoload['libraries']) AND isset($autoload['core']))
{
$autoload['libraries'] = $autoload['core'];
}
// Load libraries
if (isset($autoload['libraries']) AND count($autoload['libraries']) > 0)
{
// Load the database driver.
if (in_array('database', $autoload['libraries']))
{
$this->database();
$autoload['libraries'] = array_diff($autoload['libraries'], array('database'));
}
// Load all other libraries
foreach ($autoload['libraries'] as $item)
{
$this->library($item);
}
}
// Autoload models
if (isset($autoload['model']))
{
$this->model($autoload['model']);
}
// Autoload modules
if (isset($autoload['module']))
{
$this->module($autoload['module']);
}
}
}
You can use the above in your controller via:
$this->load->module('test_module');
$this->test_module->method();

Answer 2

If i am getting your problem correctly , you have to initialize the instance of CI.
Example :-
In your external file do this :-
class modules
{
var $CI;
function __construct()
{
$this->CI =& get_instance();
}
function retrieve_data()
{
// Load Model
$this->CI->load->model('YOUR MODEL NAME'); // Give the name of your model that you want to laod
}
}
Hope it helps you :)

Answer 3

As far as i understand your question the answer lies here.
Moduler Extension
download it and install according to the instructions. then you can simply access any thing with these steps.
In your controller load the module like this.
$this->load->module('pages');
Make sure you have a directory Modules under application. And your Module pages should exist there. Pages module can have controller , models , views , helpers , config and libraries etc.
Now you need to call model. Here is how you can do it.
$this->pages->model->test_model->get_test_data();
Also you should note that loading module loads all the resources.

Answer 4

If nothing works, try this
public function setPackagePaths($path, $view_cascade=TRUE, $model_cascade=TRUE, $library_cascade=TRUE, $helper_cascade=TRUE) {
$path = rtrim($path, '/').'/';
///$this->_ci_view_paths = $this->_ci_library_paths = $this->_ci_model_paths = array();
$this->_ci_library_paths = array($path.'libraries/' => $library_cascade) + $this->_ci_library_paths ;
$this->_ci_helper_paths = array($path.'helpers/' => $helper_cascade) + $this->_ci_helper_paths ;
$this->_ci_model_paths = array($path.'models/' => $model_cascade) + $this->_ci_model_paths ;
$this->_ci_view_paths = array($path.'views/' => $view_cascade) + $this->_ci_view_paths;
// Add config file path
$config =& $this->_ci_get_component('config');
array_unshift($config->_config_paths, $path);
}
Its a hardcore way to update this function to Loader Class. But works fine.