Loader Class

/application/third_party/foo_bar

config/
helpers/
language/
libraries/
models/

$this->load->add_package_path(APPPATH.'my_app', FALSE);
$this->load->view('my_app_index'); // Loads
$this->load->view('welcome_message'); // Will not load the default welcome_message b/c the second param to add_package_path is FALSE

// Reset things
$this->load->remove_package_path(APPPATH.'my_app');

// Again without the second parameter:
$this->load->add_package_path(APPPATH.'my_app');
$this->load->view('my_app_index'); // Loads
$this->load->view('welcome_message'); // Loads

.. php:method:: library($library[, $params = NULL[, $object_name = NULL]])

	:param	mixed	$library: Library name as a string or an array with multiple libraries
	:param	array	$params: Optional array of parameters to pass to the loaded library's constructor
	:param	string	$object_name: Optional object name to assign the library to
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	This method is used to load core classes.

	.. note:: We use the terms "class" and "library" interchangeably.

	For example, if you would like to send email with CodeIgniter, the first
	step is to load the email class within your controller::

		$this->load->library('email');

	Once loaded, the library will be ready for use, using ``$this->email``.

	Library files can be stored in subdirectories within the main
	"libraries" directory, or within your personal *application/libraries*
	directory. To load a file located in a subdirectory, simply include the
	path, relative to the "libraries" directory. For example, if you have
	file located at::

		libraries/flavors/Chocolate.php

	You will load it using::

		$this->load->library('flavors/chocolate');

	You may nest the file in as many subdirectories as you want.

	Additionally, multiple libraries can be loaded at the same time by
	passing an array of libraries to the load method.
	::

		$this->load->library(array('email', 'table'));

	**Setting options**

	The second (optional) parameter allows you to optionally pass
	configuration setting. You will typically pass these as an array::

		$config = array (
			'mailtype' => 'html',
			'charset'  => 'utf-8',
			'priority' => '1'
		);

		$this->load->library('email', $config);

	Config options can usually also be set via a config file. Each library
	is explained in detail in its own page, so please read the information
	regarding each one you would like to use.

	Please take note, when multiple libraries are supplied in an array for
	the first parameter, each will receive the same parameter information.

	**Assigning a Library to a different object name**

	If the third (optional) parameter is blank, the library will usually be
	assigned to an object with the same name as the library. For example, if
	the library is named Calendar, it will be assigned to a variable named
	``$this->calendar``.

	If you prefer to set your own class names you can pass its value to the
	third parameter::

		$this->load->library('calendar', NULL, 'my_calendar');

		// Calendar class is now accessed using:
		$this->my_calendar

	Please take note, when multiple libraries are supplied in an array for
	the first parameter, this parameter is discarded.

.. php:method:: driver($library[, $params = NULL[, $object_name]])

	:param	mixed	$library: Library name as a string or an array with multiple libraries
	:param	array	$params: Optional array of parameters to pass to the loaded library's constructor
	:param	string	$object_name: Optional object name to assign the library to
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	This method is used to load driver libraries, acts very much like the
	``library()`` method.

	As an example, if you would like to use sessions with CodeIgniter, the first
	step is to load the session driver within your controller::

		$this->load->driver('session');

	Once loaded, the library will be ready for use, using ``$this->session``.

	Driver files must be stored in a subdirectory within the main
	"libraries" directory, or within your personal *application/libraries*
	directory. The subdirectory must match the parent class name. Read the
	:doc:`Drivers <../general/drivers>` description for details.

	Additionally, multiple driver libraries can be loaded at the same time by
	passing an array of drivers to the load method.
	::

		$this->load->driver(array('session', 'cache'));

	**Setting options**

	The second (optional) parameter allows you to optionally pass
	configuration settings. You will typically pass these as an array::

		$config = array(
			'sess_driver' => 'cookie',
			'sess_encrypt_cookie'  => true,
			'encryption_key' => 'mysecretkey'
		);

		$this->load->driver('session', $config);

	Config options can usually also be set via a config file. Each library
	is explained in detail in its own page, so please read the information
	regarding each one you would like to use.

	**Assigning a Driver to a different object name**

	If the third (optional) parameter is blank, the library will be assigned
	to an object with the same name as the parent class. For example, if
	the library is named Session, it will be assigned to a variable named
	``$this->session``.

	If you prefer to set your own class names you can pass its value to the
	third parameter::

		$this->load->library('session', '', 'my_session');

		// Session class is now accessed using:
		$this->my_session

.. php:method:: view($view[, $vars = array()[, return = FALSE]])

	:param	string	$view: View name
	:param	array	$vars: An associative array of variables
	:param	bool	$return: Whether to return the loaded view
	:returns:	View content string if $return is set to TRUE, otherwise CI_Loader instance (method chaining)
	:rtype:	mixed

	This method is used to load your View files. If you haven't read the
	:doc:`Views <../general/views>` section of the user guide it is
	recommended that you do since it shows you how this method is
	typically used.

	The first parameter is required. It is the name of the view file you
	would like to load.

	.. note:: The .php file extension does not need to be specified unless
		you use something other than .php.

	The second **optional** parameter can take an associative array or an
	object as input, which it runs through the PHP
	`extract() <https://secure.php.net/extract>`_ function to convert to variables
	that can be used in your view files. Again, read the
	:doc:`Views <../general/views>` page to learn how this might be useful.

	The third **optional** parameter lets you change the behavior of the
	method so that it returns data as a string rather than sending it to
	your browser. This can be useful if you want to process the data in some
	way. If you set the parameter to TRUE (boolean) it will return data. The
	default behavior is FALSE, which sends it to your browser. Remember to
	assign it to a variable if you want the data returned::

		$string = $this->load->view('myfile', '', TRUE);

.. php:method:: vars($vars[, $val = ''])

	:param	mixed	$vars: An array of variables or a single variable name
	:param	mixed	$val: Optional variable value
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	This method takes an associative array as input and generates
	variables using the PHP `extract() <https://secure.php.net/extract>`_
	function. This method produces the same result as using the second
	parameter of the ``$this->load->view()`` method above. The reason you
	might want to use this method independently is if you would like to
	set some global variables in the constructor of your controller and have
	them become available in any view file loaded from any method. You can
	have multiple calls to this method. The data get cached and merged
	into one array for conversion to variables.

.. php:method:: get_var($key)

	:param	string	$key: Variable name key
	:returns:	Value if key is found, NULL if not
	:rtype:	mixed

	This method checks the associative array of variables available to
	your views. This is useful if for any reason a var is set in a library
	or another controller method using ``$this->load->vars()``.

.. php:method:: get_vars()

	:returns:	An array of all assigned view variables
	:rtype:	array

	This method retrieves all variables available to your views.

.. php:method:: clear_vars()

	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	Clears cached view variables.

.. php:method:: model($model[, $name = ''[, $db_conn = FALSE]])

	:param	mixed	$model: Model name or an array containing multiple models
	:param	string	$name: Optional object name to assign the model to
	:param	string	$db_conn: Optional database configuration group to load
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	::

		$this->load->model('model_name');


	If your model is located in a subdirectory, include the relative path
	from your models directory. For example, if you have a model located at
	*application/models/blog/Queries.php* you'll load it using::

		$this->load->model('blog/queries');

	If you would like your model assigned to a different object name you can
	specify it via the second parameter of the loading method::

		$this->load->model('model_name', 'fubar');
		$this->fubar->method();

.. php:method:: database([$params = ''[, $return = FALSE[, $query_builder = NULL]]])

	:param	mixed	$params: Database group name or configuration options
	:param	bool	$return: Whether to return the loaded database object
	:param	bool	$query_builder: Whether to load the Query Builder
	:returns:	Loaded CI_DB instance or FALSE on failure if $return is set to TRUE, otherwise CI_Loader instance (method chaining)
	:rtype:	mixed

	This method lets you load the database class. The two parameters are
	**optional**. Please see the :doc:`database <../database/index>`
	section for more info.

.. php:method:: dbforge([$db = NULL[, $return = FALSE]])

	:param	object	$db: Database object
	:param	bool	$return: Whether to return the Database Forge instance
	:returns:	Loaded CI_DB_forge instance if $return is set to TRUE, otherwise CI_Loader instance (method chaining)
	:rtype:	mixed

	Loads the :doc:`Database Forge <../database/forge>` class, please refer
	to that manual for more info.

.. php:method:: dbutil([$db = NULL[, $return = FALSE]])

	:param	object	$db: Database object
	:param	bool	$return: Whether to return the Database Utilities instance
	:returns:	Loaded CI_DB_utility instance if $return is set to TRUE, otherwise CI_Loader instance (method chaining)
	:rtype:	mixed

	Loads the :doc:`Database Utilities <../database/utilities>` class, please
	refer to that manual for more info.

.. php:method:: helper($helpers)

	:param	mixed	$helpers: Helper name as a string or an array containing multiple helpers
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	This method loads helper files, where file_name is the name of the
	file, without the _helper.php extension.

.. php:method:: file($path[, $return = FALSE])

	:param	string	$path: File path
	:param	bool	$return: Whether to return the loaded file
	:returns:	File contents if $return is set to TRUE, otherwise CI_Loader instance (method chaining)
	:rtype:	mixed

	This is a generic file loading method. Supply the filepath and name in
	the first parameter and it will open and read the file. By default the
	data is sent to your browser, just like a View file, but if you set the
	second parameter to boolean TRUE it will instead return the data as a
	string.

.. php:method:: language($files[, $lang = ''])

	:param	mixed	$files: Language file name or an array of multiple language files
	:param	string	$lang: Language name
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	This method is an alias of the :doc:`language loading
	method <language>`: ``$this->lang->load()``.

.. php:method:: config($file[, $use_sections = FALSE[, $fail_gracefully = FALSE]])

	:param	string	$file: Configuration file name
	:param	bool	$use_sections: Whether configuration values should be loaded into their own section
	:param	bool	$fail_gracefully: Whether to just return FALSE in case of failure
	:returns:	TRUE on success, FALSE on failure
	:rtype:	bool

	This method is an alias of the :doc:`config file loading
	method <config>`: ``$this->config->load()``

.. php:method:: is_loaded($class)

	:param	string	$class: Class name
	:returns:	Singleton property name if found, FALSE if not
	:rtype:	mixed

	Allows you to check if a class has already been loaded or not.

	.. note:: The word "class" here refers to libraries and drivers.

	If the requested class has been loaded, the method returns its assigned
	name in the CI Super-object and FALSE if it's not::

		$this->load->library('form_validation');
		$this->load->is_loaded('Form_validation');	// returns 'form_validation'

		$this->load->is_loaded('Nonexistent_library');	// returns FALSE

	.. important:: If you have more than one instance of a class (assigned to
		different properties), then the first one will be returned.

	::

		$this->load->library('form_validation', $config, 'fv');
		$this->load->library('form_validation');

		$this->load->is_loaded('Form_validation');	// returns 'fv'

.. php:method:: add_package_path($path[, $view_cascade = TRUE])

	:param	string	$path: Path to add
	:param	bool	$view_cascade: Whether to use cascading views
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	Adding a package path instructs the Loader class to prepend a given path
	for subsequent requests for resources. As an example, the "Foo Bar"
	application package above has a library named Foo_bar.php. In our
	controller, we'd do the following::

		$this->load->add_package_path(APPPATH.'third_party/foo_bar/')
			->library('foo_bar');

.. php:method:: remove_package_path([$path = ''])

	:param	string	$path: Path to remove
	:returns:	CI_Loader instance (method chaining)
	:rtype:	CI_Loader

	When your controller is finished using resources from an application
	package, and particularly if you have other application packages you
	want to work with, you may wish to remove the package path so the Loader
	no longer looks in that directory for resources. To remove the last path
	added, simply call the method with no parameters.

	Or to remove a specific package path, specify the same path previously
	given to ``add_package_path()`` for a package.::

		$this->load->remove_package_path(APPPATH.'third_party/foo_bar/');

.. php:method:: get_package_paths([$include_base = TRUE])

	:param	bool	$include_base: Whether to include BASEPATH
	:returns:	An array of package paths
	:rtype:	array

	Returns all currently available package paths.