Create RESTful API in CodeIgniter 4

In CodeIgniter 4, there is already CodeIgniter\RESTful\ResourceController that make building RESTful API easier. It can consume the model by provide modelName property.

Preparation

1. Register Routes

// app/Config/Routes.php
$routes->resource('products');

2. Create Model and Entity Classes

For example, we have the ProductModel class:

<?php namespace App\Models;

use App\Entities\Product;
use CodeIgniter\Model;

class ProductModel extends Model
{
    protected $table           = 'product';

    /**
     *  $returnType as entity class  in RESTful API might not work in CodeIgniter 4.0.2.
     *  You can define as "object" at CodeIgniter 4.0.2 for RESTful API usage.
     *
     *       protected $returnType      = 'object';
     *
     */
    protected $returnType      = Product::class;

    protected $allowedFields   = [
        'product_code',
        'product_name',
    ];
    protected $validationRules = [
        'product_code' => 'required|alpha_numeric|exact_length[5]|is_unique[product.product_code,id,{id}]',
        'product_name' => 'required|alpha_numeric_space|min_length[3]|max_length[255]|is_unique[product.product_name,id,{id}]',
    ];
}

Above model require entity class, so, we can create as follow:

<?php namespace App\Entities;

use CodeIgniter\Entity;

class Product extends Entity
{
    protected $attributes = [
        'product_code' => null,
        'product_name' => null,
    ];

        // filter on create/update data if necessary
    public function setProductCode(string $productCode): self
    {
        $this->attributes['product_code'] = strtoupper($productCode);
        return $this;
    }

        // filter on create/update data if necessary
    public function setProductName(string $productName): self
    {
        $this->attributes['product_name'] = ucwords($productName);
        return $this;
    }
}

3. Ensure the pages has “csrf” filter DISABLED for the RESTful API pages

CSRF usually uses only for public web interation forms. For API, we can use authorization token (eg: for Oauth usage). We can disable csrf filter in app/Config/Filters.php like the following:

<?php namespace Config;

use App\Filters\PostRequestOnly;
use CodeIgniter\Config\BaseConfig;

class Filters extends BaseConfig
{
    // ... 

    public $globals = [
        'before' => [
            'csrf' => [
                'except' =>  [
                    '/products',
                    '/products/*',
                ],
            ],
        ],
    ];

    // ...
}

The API

We can create a controller for it, that extends CodeIgniter\RESTful\ResourceController:

<?php namespace App\Controllers;

use CodeIgniter\RESTful\ResourceController;

class Products extends ResourceController
{
    protected $modelName = 'App\Models\ProductModel';
    protected $format    = 'json';
}

For display all products, we can create method index:

// ...
    public function index()
    {
        return $this->respond($this->model->findAll());
    }
// ...

This is the output of all products:

For display product by id, we can add method show:

// ...
    public function show($id = null)
    {
        $record = $this->model->find($id);
        if (! $record)
        {
            return $this->failNotFound(sprintf(
                'product with id %d not found',
                $id
            ));
        }

        return $this->respond($record);
    }
// ...

This is the output when product found and not found:

For create new product data, we can add method create:

// ...
    public function create()
    {
        $data = $this->request->getPost();
        if (! $this->model->save($data))
        {
            return $this->fail($this->model->errors());
        }

        return $this->respondCreated($data, 'product created');
    }
// ...

Above, we use getPost() from request object to get POST data. This is the output when product creation is succeed and failed:

For update product data, we can add method update:

// ...
    public function update($id = null)
    {
        $data       = $this->request->getRawInput();
        $data['id'] = $id;

        if (! $this->model->save($data))
        {
            return $this->fail($this->model->errors());
        }

        return $this->respond($data, 200, 'product updated');
    }
// ...

Above, we use getRawInput() from request object to get PUT data. Currently, there is no “respondUpdated” method, I created Pull Request for it at https://github.com/codeigniter4/CodeIgniter4/pull/2816 for addition of “respondUpdated” method.

This is the output when product update is succeed and failed:

Now, the last one, the delete, we can add delete method:

// ...
    public function delete($id = null)
    {
        $delete = $this->model->delete($id);
        if ($this->model->db->affectedRows() === 0)
        {
            return $this->failNotFound(sprintf(
                'product with id %d not found or already deleted',
                $id
            ));
        }

        return $this->respondDeleted(['id' => $id], 'product deleted');
    }
//...

This is the output when product delete is succeed and failed:

That’s it 😉