+ +
+

Loader Class

+

Loader, as the name suggests, is used to load elements. These elements +can be libraries (classes) View files, +Drivers, +Helpers, +Models, or your own files.

+
+

Note

+

This class is initialized automatically by the system so there +is no need to do it manually.

+
+ +
+

Application “Packages”

+

An application package allows for the easy distribution of complete sets +of resources in a single directory, complete with its own libraries, +models, helpers, config, and language files. It is recommended that +these packages be placed in the application/third_party directory. Below +is a sample map of an package directory.

+

The following is an example of a directory for an application package +named “Foo Bar”.

+
/application/third_party/foo_bar
+
+config/
+helpers/
+language/
+libraries/
+models/
+
+
+

Whatever the purpose of the “Foo Bar” application package, it has its +own config files, helpers, language files, libraries, and models. To use +these resources in your controllers, you first need to tell the Loader +that you are going to be loading resources from a package, by adding the +package path via the add_package_path() method.

+
+

Package view files

+

By Default, package view files paths are set when add_package_path() +is called. View paths are looped through, and once a match is +encountered that view is loaded.

+

In this instance, it is possible for view naming collisions within +packages to occur, and possibly the incorrect package being loaded. To +ensure against this, set an optional second parameter of FALSE when +calling add_package_path().

+
$this->load->add_package_path(APPPATH.'my_app', FALSE);
+$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
+
+
+
+
+
+

Class Reference

+
+
+class CI_Loader
+
+
+library($library[, $params = NULL[, $object_name = NULL]])
+
+++ + + + + + + + +
Parameters:
    +
  • $library (mixed) – Library name as a string or an array with multiple libraries
    • +
  • $params (array) – Optional array of parameters to pass to the loaded library’s constructor
    • +
  • $object_name (string) – Optional object name to assign the library to
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

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.

+
+ +
+
+driver($library[, $params = NULL[, $object_name]])
+
+++ + + + + + + + +
Parameters:
    +
  • $library (mixed) – Library name as a string or an array with multiple libraries
    • +
  • $params (array) – Optional array of parameters to pass to the loaded library’s constructor
    • +
  • $object_name (string) – Optional object name to assign the library to
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

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 +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
+
+
+
+ +
+
+view($view[, $vars = array()[, return = FALSE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $view (string) – View name
    • +
  • $vars (array) – An associative array of variables
    • +
  • $return (bool) – Whether to return the loaded view
    • +
+
Returns:

View content string if $return is set to TRUE, otherwise CI_Loader instance (method chaining)

+
Return type:

mixed

+
+

This method is used to load your View files. If you haven’t read the +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() function to convert to variables +that can be used in your view files. Again, read the +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 = $this->load->view('myfile', '', TRUE);
+
+
+
+ +
+
+vars($vars[, $val = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $vars (mixed) – An array of variables or a single variable name
    • +
  • $val (mixed) – Optional variable value
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

CI_Loader

+
+

This method takes an associative array as input and generates +variables using the PHP 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.

+
+ +
+
+get_var($key)
+
+++ + + + + + + + +
Parameters:
    +
  • $key (string) – Variable name key
    • +
+
Returns:

Value if key is found, NULL if not

+
Return type:

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().

+
+ +
+
+get_vars()
+
+++ + + + + + +
Returns:An array of all assigned view variables
Return type:array
+

This method retrieves all variables available to your views.

+
+ +
+
+clear_vars()
+
+++ + + + + + +
Returns:CI_Loader instance (method chaining)
Return type:CI_Loader
+

Clears cached view variables.

+
+ +
+
+model($model[, $name = ''[, $db_conn = FALSE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $model (mixed) – Model name or an array containing multiple models
    • +
  • $name (string) – Optional object name to assign the model to
    • +
  • $db_conn (string) – Optional database configuration group to load
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

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();
+
+
+
+ +
+
+database([$params = ''[, $return = FALSE[, $query_builder = NULL]]])
+
+++ + + + + + + + +
Parameters:
    +
  • $params (mixed) – Database group name or configuration options
    • +
  • $return (bool) – Whether to return the loaded database object
    • +
  • $query_builder (bool) – 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)

+
Return type:

mixed

+
+

This method lets you load the database class. The two parameters are +optional. Please see the database +section for more info.

+
+ +
+
+dbforge([$db = NULL[, $return = FALSE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $db (object) – Database object
    • +
  • $return (bool) – 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)

+
Return type:

mixed

+
+

Loads the Database Forge class, please refer +to that manual for more info.

+
+ +
+
+dbutil([$db = NULL[, $return = FALSE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $db (object) – Database object
    • +
  • $return (bool) – 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)

+
Return type:

mixed

+
+

Loads the Database Utilities class, please +refer to that manual for more info.

+
+ +
+
+helper($helpers)
+
+++ + + + + + + + +
Parameters:
    +
  • $helpers (mixed) – Helper name as a string or an array containing multiple helpers
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

CI_Loader

+
+

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

+
+ +
+
+file($path[, $return = FALSE])
+
+++ + + + + + + + +
Parameters:
    +
  • $path (string) – File path
    • +
  • $return (bool) – Whether to return the loaded file
    • +
+
Returns:

File contents if $return is set to TRUE, otherwise CI_Loader instance (method chaining)

+
Return type:

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.

+
+ +
+
+language($files[, $lang = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $files (mixed) – Language file name or an array of multiple language files
    • +
  • $lang (string) – Language name
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

CI_Loader

+
+

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

+
+ +
+
+config($file[, $use_sections = FALSE[, $fail_gracefully = FALSE]])
+
+++ + + + + + + + +
Parameters:
    +
  • $file (string) – Configuration file name
    • +
  • $use_sections (bool) – Whether configuration values should be loaded into their own section
    • +
  • $fail_gracefully (bool) – Whether to just return FALSE in case of failure
    • +
+
Returns:

TRUE on success, FALSE on failure

+
Return type:

bool

+
+

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

+
+ +
+
+is_loaded($class)
+
+++ + + + + + + + +
Parameters:
    +
  • $class (string) – Class name
    • +
+
Returns:

Singleton property name if found, FALSE if not

+
Return type:

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');
+
+$this->load->is_loaded('Form_validation');      // returns 'fv'
+
+
+
+ +
+
+add_package_path($path[, $view_cascade = TRUE])
+
+++ + + + + + + + +
Parameters:
    +
  • $path (string) – Path to add
    • +
  • $view_cascade (bool) – Whether to use cascading views
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

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:

+
$this->load->add_package_path(APPPATH.'third_party/foo_bar/')
+        ->library('foo_bar');
+
+
+
+ +
+
+remove_package_path([$path = ''])
+
+++ + + + + + + + +
Parameters:
    +
  • $path (string) – Path to remove
    • +
+
Returns:

CI_Loader instance (method chaining)

+
Return type:

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.:

+
$this->load->remove_package_path(APPPATH.'third_party/foo_bar/');
+
+
+
+ +
+
+get_package_paths([$include_base = TRUE])
+
+++ + + + + + + + +
Parameters:
    +
  • $include_base (bool) – Whether to include BASEPATH
    • +
+
Returns:

An array of package paths

+
Return type:

array

+
+

Returns all currently available package paths.

+
+ +
+ +
+
+ + +