Create RESTful API with Code Igniter #5 : Get user data, Encode data, and Generate token

Repository

https://github.com/bcit-ci/CodeIgniter

What Will I Learn?

• Get user data for data payload to encode
• Encode data
• Generate token

Requirements

• Basic PHP
• Install Ci > 3.1
• Local server (Xampp, Wampp, or etc)
• Mysqli

Resources

• Code igneter - https://www.codeigniter.com/
• JSON Web tokens - https://jwt.io/

Difficulty

Basic

Tutorial Content

In this tutorial, we will continue the previous tutorial series, in the previous tutorial, We have checked whether the email and password of a user are valid or not. Then we will start using the token system in our authentication system. We have checked a valid user or not like the picture below:

Get input user

We have checked a valid user, now we will encode user data. to get user data we can take the value like the following:

• Get user data from email

public function login() {
        if (!$this->user->is_valid()) { //CHECK IF USER VALID OR NOT
            return $this->response([
                'success'   => false,
                'message'   => 'Password or Email is wrong'
            ]);
}
        // IF USER VALID GET USER DATA FROM EMAIL
        
        $email = $this->input->post('email');   //GET USER INPUT 'email'
        $user = $this->user->get_all('email',$email);   //GET USER DATA
}

• Get user input: We can take input values that are POST by the user like this $email = $this->input->post('email);. 'email' is the key that was POST.

• Get user data: If the user is valid then we will fetch user data from the email $user = $this->user->get_all('email',$email);. We can use the function get_all() in the models User.php. The following is the code snippet from User.php that we created in the previous tutorial series.

public function get_all($key = null, $value = null) {
       if($key != null) {
           $query  = $this->db->get_where('users', array($key => $value));
           return $query->result();
       }
       $query  = $this->db->get('users');
       return $query->result();
   }

in the function get_all('email',$email) We have two parameters, key and value. the key is the 'email' and the value is $email. The following are the data that we managed to take from $user = $this->user->get_all('email',$email);

array(1) {
  [0]=>
  object(stdClass)#18 (5) {
    ["id"]=>
    string(1) "9"
    ["email"]=>
    string(20) "[email protected]"
    ["password"]=>
    string(60) "$2y$10$KJnQm6seBE6J61ARqjT8MeuniH.D2grQhBQho4Q4aiit0aIQnCBL2"
    ["created_at"]=>
    string(19) "2018-10-24 22:06:05"
    ["updated_at"]=>
    string(19) "0000-00-00 00:00:00"
  }
}

Encode token

Encode is the process of converting information from a source (object) into data, which is then sent to the recipient or observer, as in the data processing system. Now we will encode based on user data and some other additional data.

• Collect data

Before we encode data to generate tokens, we need to collect the data needed to encode tokens. The following are the data that we will use to encode:

$date = new DateTime();
// Collect data
        $payload['id']      = $user[0]->id
        $payload['email']   = $user[0]->email;
        $payload['iat']     = $date->getTimestamp();
        $payload['exp']     = $date->getTimestamp() + 60*60*2;
        
var_dump ($payload);

$payload is a variable in the form of an array. The keys are:

1. $payload['id'] is id value from $user[0]->id;
2. $payload['email'] is email value from $user[0]->email;
3. $payload['iat'] iat is just a key that stands for in At
4. $payload['exp'] exp is just a key for expired time.

The Display when we do var_dump ($payload) to see the $payload data structure.

array(4) {
  ["id"]=>
  string(1) "9"
  ["email"]=>
  string(20) "[email protected]"
  ["iat"]=>
  int(1540702117)
  ["exp"]=>
  int(1540709317)
}

• Encode token

After we get all the data that we need, then we will encode all data. to encode we can use JWT: :($payload, $this->secret). $payload is the data that we will encode and $this-> secret is a secret key to be combined with encoded data.

public function login() {
        if (!$this->user->is_valid()) {
            return $this->response([
                'success'   => false,
                'message'   => 'Password or Email is wrong'
            ]);
        }

        //Get User data
        $email = $this->input->post('email');
        $user = $this->user->get_all('email',$email);

        // Collect data
        $date = new DateTime();
        $payload['id']      = $user[0]->id;
        $payload['email']   = $user[0]->email;
        $payload['iat']     = $date->getTimestamp();
        $payload['exp']     = $date->getTimestamp() + 60*60*2;

        // Encode data
        $output['id_token'] = JWT::encode($payload, $this->secret);
        $this->response($output); // Show the result to JSON
    }

We can save the encoded data results in an array that is $output['id_token']. Tokens are encoded from $payload and $this-> secret

We can create a $secret as a variable like this:

private $secret = "This is a secret key"; // CREATE VARIABLE TO PRIVATE

and then we can see the results in POSTMAN because we have displayed the data in JSON $this->response($output);, the following is an example:

You can see as the picture above, we have succeeded to get the token that results from generating the data that we have collected from user data. Now we can save this token as access to our RESTfull API.

We have successfully generated tokens based on the data we encode. in the next tutorial, we will use this token as access to recognize valid users and we will also use it as a middleware so we can set any endpoints that can be accessed by the user. thank you for following this tutorial, hopefully, can help you.

Curriculum

Create RESTful API with Code Igniter #1 : Basic installation, Setup configuration and Database, Create Routes API

Create RESTful API with Code Igniter #2 : Create API register, Models and Controllers, JSON Response

Create RESTful API with Code Igniter #3 : Create Endpoint for Users and User detail, Dynamic functions

Create RESTful API with Code Igniter #4 : JWT(JSON Web Token) Concept, Login function and Decode password

Proof of workdone

https://github.com/milleaduski/RESTful-CI