In this example, we will demonstrate business logic. Ordering a product will trigger the model to update the product's quantity and check whether it's smaller than a certain amount.
This example will be constructed from the following controllers, model, and view:
application/controllers/order.php: This controller loads the modelproductmodel$this->load->model(' productmodel'): This controller renders the vieworderview, which displays all the products, and where each product has links to ordering a productapplication/models/productmodel.php: This model contains functions, which retrieve products, updates its quantity, and checks its quantityapplication/views/ orderview.php: The view displays all the products in a table, where each row has a link for ordering the product
Let us assume the URI to the project root is http://mydomain.com/myproject and http://mydomain.com/myproject/order.
The controller PHP file is located at application/controllers/order.php.
This controller is responsible for displaying the products and updates each product. If the product's quantity reaches a limit, it generates an error message.
The code and inline explanations are as follows:
<?php
if (!defined('BASEPATH')) exit('No direct script access allowed'),
class Order extends CI_Controller
{
// This method retrieves the products list and returns an array // of objects each containing product details
public function index()
{
// Loading the url helper
$this->load->helper('url'),
// Manually loading the database
$this->load->database();
// Loading the model class
$this->load->model('productmodel'),
$view_params['products'] = $this->productmodel->get_products();
$this->load->view('orderview', $view_params);
}
// This method checks the product's quantity.
// It updates the product row in the database or generates an // error message
public function product($product_id)
{
// Loading the url helper
$this->load->helper('url'),
// Manually loading the database
$this->load->database();
// Loading the model class
$this->load->model('productmodel'),
if (!$this->productmodel->update_quantity($product_id)) {
mail($user_mail, 'product' . $product_id . "reached it's limit", 'Order product' . $product_id);
}
redirect('product'),
}
}The model PHP file is located at application/models/productmodel.php.
In this example, the methods of the CI object db are called for generating and executing the SQL queries.
Please refer to the CI database's library available at http://ellislab.com/codeigniter/user-guide/database/index.html.
The code and inline explanations are as follows:
<?php
class Productmodel extends CI_Model
{
// The model's constructor method
public function __construct()
{
// Call the model constructor
parent::__construct();
}
// This method retrieves the products list and returns an array of // objects each containing product details.
public function get_products()
{
// Calling the CI's db object's method for generating the // SQL queries.
$query = $this->db->get('products'),
// returns an array of products objects
return $query->result();
}
// This method retrieves a specific product's details // identified by $product_id as a parameter.
public function get_product($product_id)
{
// Calling the CI's db object's methods for generating the // SQL queries.
$this->db->select('*'),
$this->db->from('products'),
$this->db->where('product_id', $product_id);
// Calling the CI's db object method for executing the query
$query = $this->db->get();
// Returning array of one object element containing the product // details.
return $query->result();
}
// This method adds a product to the products table parameters.
// $data - The data to insert into the table
public function addProduct($data)
{
// Calling the CI's db object method for inserting a product data // into the products table.
$this->db->insert('products', $data);
}
// This method updates a product row in the products table // parameters.
// $product_id - The product id
// $data - The updated data
public function updateProduct($product_id, $data)
{
// Calling the CI's db object's methods for generating the // SQL queries.
$this->db->where('product_id', $product_id);
// Calling the CI's db object method for updating the product data // in the products table.
$this->db->update('products', $data);
}
// This method checks whether the quantity exceeds it's limit.
private function check_quantity($product_id) {
// Calling the CI's db object's methods for generating the // SQL queries.
$this->db->select('product_quantity'),
$this->db->from('products'),
$this->db->where('product_id', $product_id);
// Calling the CI's db object method for executing the query.
$query = $this->db->get();
// Calling the result's method row, which returns the SQL query // result row.
$row = $query->row();
if ($row->product_quantity < 7) {
return false;
} else {
return true;
}
}
// This method updates a product quantity and return true or false, // if quantity reaches it's limit.
public function update_quantity($product_id)
{
$sql = "UPDATE products SET product_quantity = product_quantity - 1 WHERE product_id=" $product_id;
$this->db->query($sql);
// Checking if the quantity reached it's limit.
if ($this->check_quantity($product_id)) {
return true;
} else {
return false;
}
}
}The PHP view file is located at application/views/orderview.php. This view file displays a table with the products list.
The following are the code and inline explanations:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Products List</title>
</head>
<body>
<table>
<tr>
<th>ID</th>
<th>Name</th>
<th>SKU</th>
<th>Quantity</th>
<th>Actions</th>
</tr>
<?php foreach ($products as $product): ?>
<tr>
<td><?php echo $product->product_id; ?></td>
<td><?php echo $product->product_name; ?></td>
<td><?php echo $product->product_sku ; ?></td>
<td><?php echo $product->product_quantity ; ?></td>
<td><a href="<?php echo site_url("order/product/" . $product->product_id); ?>">Order Product</a></td>
</tr>
<?php endforeach; ?>
</table>
</body>
</html>..................Content has been hidden....................
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