CodeIgniter 4 Rest Api Example Tutorial

In this tutorial, you will learn how to make CRUD rest API in PHP Codeigniter 4 frameworks with MySQL database and use it with postman application.

How to Create RESTful APIs in CodeIgniter 4

Use the following steps to create rest API in CodeIgniter 4 framework with MySQL database and call endpoints with postman application:

• Step 1: Setup Database and Table
• Step 2: Setup Codeigniter Project
• Step 3: Basic Configurations
• Step 4: Setup Database Credentials
• Step 5: Create Model
• Step 6: Create Controller
• Step 7: Start Development server

Step 1: Setup Database and Table

First of all, create database by using the following SQL query command:

CREATE DATABASE demo;

After that, select your database and run the following sql query to create a Product table into your database:

CREATE TABLE product(
product_id INT(11) PRIMARY KEY AUTO_INCREMENT,
product_name VARCHAR(200),
product_price DOUBLE
)ENGINE=INNODB;

Step 2: Setup Codeigniter 4 Project

In this step, we will download the latest version of Codeigniter 4, Go to this link https://codeigniter.com/download Download Codeigniter 4 fresh new setup and unzip the setup in your local system xampp/htdocs/ . And change the download folder name “demo”

Step 3: Basic Configurations

Next, we will set some basic configuration on the app/config/app.php file, so let’s go to application/config/config.php and open this file on text editor.

Set Base URL like this

public $baseURL = 'http://localhost:8080';
To
public $baseURL = 'http://localhost/demo/';

Step 4: Setup Database Credentials

In this step, we need to connect our project to the database. we need to go app/Config/Database.php and open database.php file in text editor. After opening the file in a text editor, We need to set up database credentials in this file like below.

	public $default = [
		'DSN'      => '',
		'hostname' => 'localhost',
		'username' => 'root',
		'password' => '',
		'database' => 'demo',
		'DBDriver' => 'MySQLi',
		'DBPrefix' => '',
		'pConnect' => false,
		'DBDebug'  => (ENVIRONMENT !== 'production'),
		'cacheOn'  => false,
		'cacheDir' => '',
		'charset'  => 'utf8',
		'DBCollat' => 'utf8_general_ci',
		'swapPre'  => '',
		'encrypt'  => false,
		'compress' => false,
		'strictOn' => false,
		'failover' => [],
		'port'     => 3306,
	];

Step 5: Create Model

So go to app/Models/ and create here one model. And you need to create one model name ProductModel.php and update the following code into your ProductModel.php file:

<?php namespace App\Models;
 
use CodeIgniter\Model;
 
class ProductModel extends Model
{
    protected $table = 'product';
    protected $primaryKey = 'product_id';
    protected $allowedFields = ['product_name','product_price'];
}

Step 6: Create Controller

Now, Navigate app/Controllers and create a controller name Products.php. Then update the following method into Products.php controller file:

<?php namespace App\Controllers;
 
use CodeIgniter\RESTful\ResourceController;
use CodeIgniter\API\ResponseTrait;
use App\Models\ProductModel;
 
class Products extends ResourceController
{
    use ResponseTrait;
    // get all product
    public function index()
    {
        $model = new ProductModel();
        $data = $model->findAll();
        return $this->respond($data);
    }
 
    // get single product
    public function show($id = null)
    {
        $model = new ProductModel();
        $data = $model->getWhere(['product_id' => $id])->getResult();
        if($data){
            return $this->respond($data);
        }else{
            return $this->failNotFound('No Data Found with id '.$id);
        }
    }
 
    // create a product
    public function create()
    {
        $model = new ProductModel();
        $data = [
            'product_name' => $this->request->getVar('product_name'),
            'product_price' => $this->request->getVar('product_price')
        ];
        $model->insert($data);
        $response = [
            'status'   => 201,
            'error'    => null,
            'messages' => [
                'success' => 'Data Saved'
            ]
        ];
        return $this->respondCreated($response);
    }
 
    // update product
    public function update($id = null)
    {
        $model = new ProductModel();
        $input = $this->request->getRawInput();
        $data = [
            'product_name' => $input['product_name'],
            'product_price' => $input['product_price']
        ];
        $model->update($id, $data);
        $response = [
            'status'   => 200,
            'error'    => null,
            'messages' => [
                'success' => 'Data Updated'
            ]
        ];
        return $this->respond($response);
    }
 
    // delete product
    public function delete($id = null)
    {
        $model = new ProductModel();
        $data = $model->find($id);
        if($data){
            $model->delete($id);
            $response = [
                'status'   => 200,
                'error'    => null,
                'messages' => [
                    'success' => 'Data Deleted'
                ]
            ];
            return $this->respondDeleted($response);
        }else{
            return $this->failNotFound('No Data Found with id '.$id);
        }
         
    }
 
}

In the above controller method works as follow:

• Index() – This is used to fetch all product.
• create() – This method is used to insert product info into DB table.
• update() – This is used to validate the form data server-side and update it into the MySQL database.
• show() – This method is used to fetch single product info into DB table.
• delete() – This method is used to delete data from the MySQL database.

Now “Routes.php” file from App/Configuration folder and define route in it:

$Route->get('/', 'home :: index');

Then, change the following:

$Route->resource('product');

This configuration allows us to access the following EndPoint:

Step 7: Start Development server

Open your terminal and run the following command to start development server:

php spark serve

Next, Open the postman app to call above created APIs as follow:

1: Get all products info from DB table, you can call get all product info api in postman app as follow:

http://localhost:8080/products

2: And if you want to get single product info, you can use the as follow in postman app:

http://localhost:8080/products/10

3: For insert new product info into DB table, you can call create apis as follow:

http://localhost:8080/products

4: For update info into DB table using the update api, you can call update info api as follow:

5: For delete product info using codeigniter api, you can call delete api as follow:

Conclusion

In this Codeigniter 4 rest API example tutorial, you have learned how to create restful API in Codeigniter 4 framework.

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