Loading Codeigniter library from a different folder under application folder

Question

Hi I am having an issue

Say I have a folder structure in CodeIgniter

application/
    controllers/
    models/
    views/
    gmail_library/

Now I have written a controller

class invite_friends extends CI_Controller {

    function __construct() {
        parent::__construct();
        $this->load->gmail_library('Config'); // this line is giving me error
        session_start();
    }
}

How can I set this thing like this?

Answer 1

First of all, note that CodeIgniter doesn't use overloading by __call() to implement dynamic methods. Thus there is no way to get such a gmail_library() methods to work.

The conventional method

From the User Guide :

Your library classes should be placed within your application/libraries folder, as this is where CodeIgniter will look for them when they are initialized.

If you're using CI Loader class to load a library or helper, you should follow CI's conventions.

application/libraries/Myclass.php

$this->load->library('myclass');
$this->myclass->my_method();

Using relative paths

1) You put your library files in sub-directories within the main libraries folder:

_{application/libraries/gmail/Gmail_config.php
I renamed your Config.php file name to prevent the occurrence of conflict with CI config core class.}

$this->load->library('gmail/gmail_config');

2) Also you can use relative path within the Loader::library() method to load the library file from the outside of the library folder, as follows:

_{The path to the file is relative. So you can use ../ to go one UP level in path.
Again: I renamed your Config.php file name to prevent the occurrence of conflict with CI config core class.}

$this->load->library('../gmail_library/Gmail_config');

Answer 2

An old question, I know, but I came across this looking for a way to use classes (libraries) from outside the application folder and I liked to keep it in 'the CI way of doing this'. I ended up extending the CI_Loader class:

I basically copied the _ci_load_class function and added an absolute path

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

class MY_Loader extends CI_Loader {

    protected $absPath = '/home/xxxxx/[any-path-you-like]/common/';

    /**
     * Load class
     *
     * This function loads the requested class.
     *
     * @param   string  the item that is being loaded
     * @param   mixed   any additional parameters
     * @param   string  an optional object name
     * @return  void
     */
    public function commonLibrary($class, $params = NULL, $object_name = NULL)
    {
        // Get the class name, and while we're at it trim any slashes.
        // The directory path can be included as part of the class name,
        // but we don't want a leading slash
        $class = str_replace('.php', '', trim($class, '/'));

        // Was the path included with the class name?
        // We look for a slash to determine this
        $subdir = '';
        if (($last_slash = strrpos($class, '/')) !== FALSE)
        {
            // Extract the path
            $subdir = substr($class, 0, $last_slash + 1);

            // Get the filename from the path
            $class = substr($class, $last_slash + 1);
        }

        // We'll test for both lowercase and capitalized versions of the file name
        foreach (array(ucfirst($class), strtolower($class)) as $class)
        {
            $subclass = $this->absPath.'libraries/'.$subdir.config_item('subclass_prefix').$class.'.php';

            // Is this a class extension request?
            if (file_exists($subclass))
            {
                $baseclass = BASEPATH.'libraries/'.ucfirst($class).'.php';

                if ( ! file_exists($baseclass))
                {
                    log_message('error', "Unable to load the requested class: ".$class);
                    show_error("Unable to load the requested class: ".$class);
                }

                // Safety:  Was the class already loaded by a previous call?
                if (in_array($subclass, $this->_ci_loaded_files))
                {
                    // Before we deem this to be a duplicate request, let's see
                    // if a custom object name is being supplied.  If so, we'll
                    // return a new instance of the object
                    if ( ! is_null($object_name))
                    {
                        $CI =& get_instance();
                        if ( ! isset($CI->$object_name))
                        {
                            return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
                        }
                    }

                    $is_duplicate = TRUE;
                    log_message('debug', $class." class already loaded. Second attempt ignored.");
                    return;
                }

                include_once($baseclass);
                include_once($subclass);
                $this->_ci_loaded_files[] = $subclass;

                return $this->_ci_init_class($class, config_item('subclass_prefix'), $params, $object_name);
            }

            // Lets search for the requested library file and load it.
            $is_duplicate = FALSE;
            foreach ($this->_ci_library_paths as $path)
            {
                $filepath = $this->absPath.'libraries/'.$subdir.$class.'.php';

                // Does the file exist?  No?  Bummer...
                if ( ! file_exists($filepath))
                {
                    continue;
                }

                // Safety:  Was the class already loaded by a previous call?
                if (in_array($filepath, $this->_ci_loaded_files))
                {
                    // Before we deem this to be a duplicate request, let's see
                    // if a custom object name is being supplied.  If so, we'll
                    // return a new instance of the object
                    if ( ! is_null($object_name))
                    {
                        $CI =& get_instance();
                        if ( ! isset($CI->$object_name))
                        {
                            return $this->_ci_init_class($class, '', $params, $object_name);
                        }
                    }

                    $is_duplicate = TRUE;
                    log_message('debug', $class." class already loaded. Second attempt ignored.");
                    return;
                }

                include_once($filepath);
                $this->_ci_loaded_files[] = $filepath;
                return $this->_ci_init_class($class, '', $params, $object_name);
            }

        } // END FOREACH

        // One last attempt.  Maybe the library is in a subdirectory, but it wasn't specified?
        if ($subdir == '')
        {
            $path = strtolower($class).'/'.$class;
            return $this->_ci_load_class($path, $params);
        }

        // If we got this far we were unable to find the requested class.
        // We do not issue errors if the load call failed due to a duplicate request
        if ($is_duplicate == FALSE)
        {
            log_message('error', "Unable to load the requested class: ".$class);
            show_error("Unable to load the requested class: ".$class);
        }
    }
}

Put the file MY_Loader.php in the application/core folder and load your libs with:

$this->load->commonLibrary('optional_subfolders/classname', 'classname');
$this->classname->awesome_method();