Description
CodeIgniter Core System Classes are used to allow own versions of class definitions and extensions. Original core classes of CodeIgniter can be swapped with the own versions or else core versions can be extended. Core System classes will not be used mostly except in the situations when required own significance.
Some of the CodeIgniter Core System Classes are:
- Benchmark : CodeIgniter Benchmark lets to log the time to run or multiple parts or lines of an application.
- Config : The Config class acts as a mediator to fetch configuration preferences.
- Controller : A Controller is basic class file that is named in a way that can be associated with a URI.
- Hooks : Hooks are used to enabled/disabled profiling for the whole applications depending on the configuration file value which will be TRUE/FALSE.
- Router : Routes gives the permission to define user own rules in URI routing.
- Exceptions : set_exception_handler function helps to handle CodeIgniter Exceptions.
- URI : URI Routing helps in mapping class/method relationship again in the given context.
- Language : Language class helps for internationalization by switching to different languages.
- Log : A log file is created each time the page runs which are controlled by the developer. log_message() writes the messages in log file.
- Input : The Input Class processes global input data before itself to maintain security.
- Output : The output class sends the finalized web page to the requesting browser.
- Loader : Loader class loads the elements like helpers, drivers.
- Security : The Security Class has various methods that maintains security for an application.
- Utf8 : Sets internal encoding for multi-byte string functions if required
Description
Open the file path application/core and create the file named "Splessons.php" (If the folder "core" is not present, it can be created manually) and enter the below code.
[php]
class CI_Splessons
{
//statements
}
[/php]
Core System classes in CodeIgniter can be extended or swapped with own versions in 3 different ways.
- Own class should extend the parent class of CodeIgniter. For example, to extend a controller use extend
CI_Controlleras a parent class. - Class type should be headed by a prefix like SP_. For example, CI_ can be replaced with SP_.
- The file name should be same as the class name. For example, if the controller name is Sp_Controller then the file name should be Sp_Controller.php.
Example
Create a controller file "SP_Controller" in the core folder present in the path folder application/core.
[php]
class SP_Controller extends CI_Controller {
public function __construct()
{
parent::__construct();
}
}
?>
[/php]
In the above code, it can be understood that SP_Controller is the own version which extends the parent controller CI_Controller.
Then create a Model in the same core folder present in application/core directory.
[php]
class SP_Model extends CI_Model
{
public function __construct()
{
// Call the CI_Model constructor
parent::__construct();
}
}
?>
[/php]
Now the above created own system classes are used as base system classes in other models and controllers. Create a model 
To see the output of the created example, enter the url 
Sample that extends the class SP_Model.
[php]
<?php
class Sample extends SP_Model
{
public function getModel()
{
echo "<h1>This is Model Function</h1>";
}
}
?>
[/php]
Then create a controller Sppage that extends the class SP_Controller.
[php]
<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Sppage extends SP_Controller {
public function index()
{
$this->load->view('welcome_message');
}
public function spmodel()
{
$this->load->model('Sample'); //calling model
$this->Sample->getModel();
}
}
[/php]
Output: When searched with the url localhost/Codeigniter/index.php/sppage the output will be as follows.
localhost/Codeigniter/index.php/sppage/spmodel.
Key Points
- CodeIgniter Core System Classes are used to allow own versions of class definitions and extensions.
- CodeIgniter Core System Classes - In application/core folder, system classes will be created.