How to implement Repository Pattern in Codeigniter? - php

Question

When I programmed in ASP.NET MVC, there was a neat pattern called Repository. I want to implment it in Codeigniter but I do not know how. Here is what I actually want:
$mock_repository = new MockRepository();
$mock_repository->add(new Item(‘title1′, ‘description1′, 1));
$mock_repository->add(new Item(‘title2′, ‘description2′, 2));
$mock_repository->add(new Item(‘title3′, ‘description3′, 1));
$controller = new Item_controller($mock_repository);
$items = $controller->get_items_by_user_id(1);
$this->_assert_equals(count($items), 2);
I am using TOAST for Unit Testing. So how do I instantiate a controller within a test? The test is of course, another controller itself.

Answer 1

From what I know, to create a Generic Repository Pattern like in C#, you need 2 things PHP 5.6 dosen't have:
Real Method Overloading.
Generic Interface or Generic Abstract Class in PHP.
Click here for more on Generic Repository Pattern in C#.
However you can still create pseudo method overloading in PHP with the help of magic method __call, and we can type little more code for the generic part of the pattern.
Note: Before creating this pattern in Codeigniter 3.0 you will need to create a table in the database, and create auto loader for folder application/libraries.
First we need to create Interface in application/libraries folder:
<?php
interface IRepository
{
public function getById($id);
public function select($columns);
public function delete($id);
}
Seconde we need to create Abstract Class implementing the Interface and extending the CI_Model to be able to use the Database librarie:
<?php
abstract class Base_repository extends CI_Model implements IRepository
{
/**
* This must be valid table name in the Database.
*
* #var string $table Name of the table.
*/
protected $table;
public function __construct()
{
parent::__construct();
}
/**
* Pseudo method overloading.
* It's called when method is not declared in the abstract class.
*
* #param string $name Name of the method
* #param mixed $arguments Arguments of the method
*/
public function __call($name, $arguments)
{
switch ($name)
{
case 'save':
if ($arguments[0]->id > 0)
{
$this->update($arguments[0]);
}
else
{
$this->insert($arguments[0]);
}
break;
}
}
/**
* Get row with id.
*
* #param integer $id
* #return mixed
*/
public function getById($id)
{
return $this->db->get_where($this->table, ['id' => $id])->row_array();
}
/**
* Select columns.
*
* #param array $columns
* #return mixed
*/
public function select($columns = ['*'])
{
$this->db->select($columns);
return $this->db->get($this->table)->result();
}
/**
* Insert data.
*
* #param object $item
* #return void
*/
private function insert($item)
{
unset($item->id);
$this->db->insert($this->table, $item);
}
/**
* Update data.
*
* #param object $item
* #return void
*/
private function update($item)
{
$this->db->where('id =', $item->id);
unset($item->id);
$this->db->update($this->table, $item);
}
/**
* Delete data.
*
* #param integer $id
* #return void
*/
public function delete($id)
{
$this->db->delete($this->table, ['id' => $id]);
}
}
Third test the repository. Make a new model in application/model, and extend Base_repository, set table name and overload save method, create entity for this model:
<?php
/**
* The entity class.
*/
class Test
{
public $id;
public $info;
}
class Test_model extends Base_repository
{
/**
* Tell what table we are using.
*/
public function __construct()
{
parent::__construct();
$this->table = 'test';
}
/**
* "Overload" save method and call it from the parent.
*
* #param test $item Make use of the Dependency Injection.
* #return void
*/
public function save(Test $item)
{
parent::save($item);
}
}
Try it in the controller. Load the model and try to get, insert, ect...
To create real models is the same procedure. If you need to add more methods that will be the same for every model add them in the abstract class if you need to create methods only for specific model add it only in this model.
I don't recommend Codeigniter freamwork. Here are some patterns for PHP CLICK!

Answer 2

You would have to completely hijack the system files to load a controller from another controller. It can't be done, methinks.

Answer 3

It can be done with HMVC.
$result = Modules::run('controller/get_items_by_user_id', $params);
$this->_assert_equals($result, $expected);