Hello Friends,

Now let's see example of how to use REST API in in codeigniter 4. This is a short guide on codeigniter 4 if REST API in. Here you will learn how to use REST API in in codeigniter 4. We will use how to use if REST API in using codeigniter 4. Let's get started with how to REST API in use in codeigniter 4.

Here i will give you many example how you can use REST API in codeigniter 4.

we require to download or install codeigniter project, it can install in a two ways, so first fire bellow command:

<?php
composer create-project codeigniter4/appstarter
?>

This step is completely optional, if you want you can open app/Config/Boot/production.php and set display_errors property to 1 and enable the error debugging in Codeigniter app.

ini_set('display_errors', '1');

We will store and manage the data in the database; that’s what REST API set out to do.

Open PHPMyAdmin and create a new database.

CREATE DATABASE demo;

Inside the demo database, create a new table employees where all the values will be stored using RESTful API.

CREATE TABLE employees (
    id int(11) NOT NULL AUTO_INCREMENT COMMENT 'Primary Key',
    name varchar(100) NOT NULL COMMENT 'Name',
    email varchar(255) NOT NULL COMMENT 'Email Address',
    PRIMARY KEY (id)
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='datatable demo table' AUTO_INCREMENT=1;
  
INSERT INTO `employees` (`id`, `name`, `email`) VALUES
(1, 'John Doe', 'john@gmail.com'),
(2, 'Vanya Hargreeves', 'vanya@gmail.com'),
(3, 'Luther Hargreeves', 'luther@gmail.com'),
(4, 'Diego Hargreeves', 'diego@gmail.com'),
(5, 'Klaus Hargreeves', 'klaus@gmail.com'),
(6, 'Ben Hargreeves', 'ben@gmail.com'),
(7, 'The Handler', 'handler@gmail.com');

If you don’t know how to connect codeigniter with MySQL database. Then, add database details such as database name, username, password in application/config/database.php file.

public $default = [
    'DSN'      => '',
    'hostname' => 'localhost',
    'username' => 'test',
    'password' => '4Mu99BhzK8dr4vF1',
    'database' => 'demo',
    'DBDriver' => 'MySQLi',
    'DBPrefix' => '',
    'pConnect' => false,
    'DBDebug'  => (ENVIRONMENT !== 'development'),
    'cacheOn'  => false,
    'cacheDir' => '',
    'charset'  => 'utf8',
    'DBCollat' => 'utf8_general_ci',
    'swapPre'  => '',
    'encrypt'  => false,
    'compress' => false,
    'strictOn' => false,
    'failover' => [],
    'port'     => 3306,
];

CodeIgniter\Database\Exceptions\DatabaseException #8

Unable to connect database : Codeigniter

If anyhow you get the Codeigniter – cannot connect to MySQL database error, then change the hostname value based on your local server e.g MAMPP or XAMPP.

# MAMPP
public $default = [
    'hostname' => '/Applications/MAMP/tmp/mysql/mysql.sock',
]

# XAMPP
public $default = [
    'hostname' => '/Applications/XAMPP/xamppfiles/var/mysql/mysql.sock',
]

Create a model file EmployeeModel.php file inside the app/Models/ directory. Place the following code inside the file to define the Model.

<?php 
namespace App\Models;
use CodeIgniter\Model;

class EmployeeModel extends Model
{
    protected $table = 'employees';
    protected $primaryKey = 'id';
    protected $allowedFields = ['name', 'email'];
}

Create a controller Employee.php in app/Controllers/ folder. In this file we will create the functions those will relentlessly handle the Create, Read, Update and Delete operations.

<?php 
namespace App\Controllers;
use CodeIgniter\RESTful\ResourceController;
use CodeIgniter\API\ResponseTrait;
use App\Models\EmployeeModel;

class Employee extends ResourceController
{
    use ResponseTrait;

    // all users
    public function index()
    {
        $model = new EmployeeModel();
        $data['employees'] = $model->orderBy('id', 'DESC')->findAll();
        return $this->respond($data);
    }

    // create
    public function create()
    {
        $model = new EmployeeModel();
        $data = [
            'name' => $this->request->getVar('name'),
            'email'  => $this->request->getVar('email'),
        ];
        $model->insert($data);
        $response = [
            'status'   => 201,
            'error'    => null,
            'messages' => [
                'success' => 'Employee created successfully'
            ]
        ];
      return $this->respondCreated($response);
    }

    // single user
    public function show($id = null)
    {
        $model = new EmployeeModel();
        $data = $model->where('id', $id)->first();
        if($data){
            return $this->respond($data);
        }else{
            return $this->failNotFound('No employee found');
        }
    }

    // update
    public function update($id = null)
    {
        $model = new EmployeeModel();
        $id = $this->request->getVar('id');
        $data = [
            'name' => $this->request->getVar('name'),
            'email'  => $this->request->getVar('email'),
        ];
        $model->update($id, $data);
        $response = [
            'status'   => 200,
            'error'    => null,
            'messages' => [
                'success' => 'Employee updated successfully'
            ] 
        ];
      return $this->respond($response);
    }

    // delete
    public function delete($id = null)
    {
        $model = new EmployeeModel();
        $data = $model->where('id', $id)->delete($id);
        if($data){
            $model->delete($id);
            $response = [
                'status'   => 200,
                'error'    => null,
                'messages' => [
                    'success' => 'Employee successfully deleted'
                ]
            ];
            return $this->respondDeleted($response);
        }else{
            return $this->failNotFound('No employee found');
        }
    }
}

The methods below deal with a particular task with RESTful API, let me enumerate all the functions performed by each method that we defined in the controller.

-> index() – Get’s all the records from the database.

-> create() – It propels an employee record into the database table.

-> show() – It gets a single employee record from the database.

-> update() – It updates the user record into the database.

-> delete() – It deletes an employee record the database.

To sustain the impetus of data between client and server we need API, to access the api we also need to define the route in CI.

Open the app/Config/Routes.php file, and look for the following code.

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

Next, remove the above line of code and add the given line of code.

$routes->resource('employee');

Eventually, we have gone through every imperative. Now, Its time to start the application using the following command:

php spark serve

Let us test out the REST API that gets all the user records from the database.

GET All Records

http://localhost:8080/employee

It will help you....