CodeIgniter MVC model

Sep 3, 2020 PHP CodeIgniter

I mainly write how to write the MVC model of CodeIgniter.

#Controller

• -Create a controller that implements a class for creating static pages.

  The class to be created inherits the CI_Controller class of system / core / Controller.php.

  Take the name of the page as an argument.

  The method to load that page is show ()

  class Pages extends CI_Controller {
  
          public function show ($ page ='home')
          {
          }
  
  }
  

• -Class inheritance –Override: If the same method is used in the small class and the parent class, Coctus takes precedence and overwrites the parent class.

• -Method

  Methods with special roles

  –Default method: index () –Method executed when the second method is empty –Remap method: _remap () –Called prior to the default method (no need for the default method) –Normal URI routing is ignored. –Output method: _output () –You can do some processing before returning the data to the user’s browser. –Constructor method: Same name as class name () –Executed only once when the controller class is called. –Convenient when you want to initialize a library that is commonly used in the controller or when you want to execute a fixed process every time.

    ```php
    function __construct () {
    // Call the constructor of the parent controller class
    parent :: __ construct ();
           
    }
    `````
  

  –Private method: _Arbitrary method name () –Cannot access directly from the URL. –Called via the default method in the following format.

    ```php
    function index ()
    {
    echo $ this-> _private_method ();
    }
  
    function _private_method ()
    {
    echo'This is a private method';
    }
    `````
  

#View

• Feature –Can be written in PHP syntax and HTML tags –Views can be linked and have a hierarchical structure. –Helpers and libraries are available directly. –There is a cache function. –You can create pseudo variables like Smarty.

• -Load View

  $ this-> load-> view ('filename', associative array of data or object)
  

  <? php
     class Hello extends CI_Controller
     {
  // Contents of index () method >>'Hello World'
        public function index ()
  {
           echo "Hello World";
        }
  
  // Contents of about () method >> about.php
  public function about ()
  {
           $ this-> load-> view ('about');
        }
  .
     }
  ?>
  

• loop –Iterate using the foreach syntax.

  // Controller
  
  function index ()
  {
  $ data ["title"] = "Sample"
  $ data ["contents"] = array ("apple", "orange")
  $ this-> load-> view ("filename", $ data);
  }
  

  <title> <? = $ title?> </ Title>
  ..
  ..
  ..
  <ul>
  <? php foreach ($ contents as $ item) :?>
  <li> <? = $ Item;?> </ Li>
  <? php endforeach;?>
  </ ul>
  

#Model

• -How to write Model

  <? php
     class Model_name extends CI_Model
     {
        public function __construct ()
  {
           parent :: __ construct ();
        }
     }
  ?>
  

• -Load Model –Read

  // When you want to read /system/application/models/read/read.php
  $ this-> load-> model ('read / read');
  

  –Method execution

  $ this-> read-> function ();