gistfile1.php

<?php

defined('BASEPATH') OR exit('No direct script access allowed');
require(APPPATH.'/libraries/REST_Controller.php');
class Welcome extends CI_Controller {
	function user_get()
	{
		if(!$this->get('id'))
		{
			$this->response(NULL, 400);
		}

		$user = $this->user_model->get( $this->get('id') );

		if($user)
		{
			$this->response($user, 200); // 200 being the HTTP response code
		}

		else
		{
			$this->response(NULL, 404);
		}
	}

	function user_post()
	{
		$result = $this->user_model->update( $this->post('id'), array(
			'name' => $this->post('name'),
			'email' => $this->post('email')
		));

		if($result === FALSE)
		{
			$this->response(array('status' => 'failed'));
		}

		else
		{
			$this->response(array('status' => 'success'));
		}

	}

	function users_get()
	{
		$users = $this->user_model->get_all();

		if($users)
		{
			$this->response($users, 200);
		}

		else
		{
			$this->response(NULL, 404);
		}
	}
}