What is wrong with this password update process?

I am working on a basic blog application in Codeigniter 3.1.8 and Bootstrap 4.

I have added a registration and login system to this application. I am current working on a password reset system.

For a reason I have not been able to figure out, the password update process is flawed. I don't know if the issue is with the controller or the model.

In the controller I have:

PHP Code:

class Newpassword extends CI_Controller {
  private $token = '';

    public function index($token) {
        $data = $this->Static_model->get_static_data();
        $data['pages'] = $this->Pages_model->get_pages();
        $data['tagline'] = 'New password';
        $data['categories'] = $this->Categories_model->get_categories();
        $this->token = $token;

        // Form validation rules
        $this->form_validation->set_rules('password', 'Password', 'required|min_length[6]');
        $this->form_validation->set_rules('cpassword', 'Confirm password', 'required|matches[password]');
        $this->form_validation->set_error_delimiters('<p class="error-message">', '</p>');

     if(!$this->form_validation->run()) {
        $this->load->view('partials/header', $data);
        $this->load->view('auth/newpassword');
        $this->load->view('partials/footer');
     } else {
        $this->add();
     }
  }

  public function add() {
    $data = $this->Static_model->get_static_data();
    $data['pages'] = $this->Pages_model->get_pages();
    $data['tagline'] = 'New password';
    $data['categories'] = $this->Categories_model->get_categories();

    // Encrypt new password
    $enc_password = password_hash($this->input->post('password'), PASSWORD_DEFAULT);

    // Update password column
    $token = $this->token;

    if ($this->Usermodel->set_new_password($token, $enc_password)) {
      redirect('login'); 
      $this->session->set_flashdata("new_password_success", "Your new password was set");
    } else {
        $this->session->set_flashdata("new_password_fail", "We have failed updateing your password");
    }
  }
} 


In the model:

PHP Code:

public function set_new_password($token, $enc_password) {
        $this->db
            ->where(['token' => $token])
            // set new password and reset token to NULL
            ->update('authors', array('password' => $enc_password, 'token' => NULL));
    }
} 


The form that is used to set the new password:

PHP Code:

<?php echo form_open(base_url('newpassword/add')); ?>
  <div class="form-group <?php if(form_error('password')) echo 'has-error';?>">
    <input type="password" name="password" id="password" class="form-control" placeholder="Password">
    <?php if(form_error('password')) echo form_error('password'); ?> 
  </div>
  <div class="form-group <?php if(form_error('cpassword')) echo 'has-error';?>">
    <input type="password" name="cpassword" id="cpassword" class="form-control" placeholder="Confirm password">
    <?php if(form_error('cpassword')) echo form_error('cpassword'); ?> 
  </div>
  <div class="form-group mb-2">
    <input type="submit" value="Set password" class="btn btn-block btn-md btn-success">
  </div>            
<?php echo form_close(); ?>

Where is my mistake?

@Ajax30,

What error messages are you getting?

@Ajax30,

What error messages are you getting?

No error message. Check the branch.

$token = ''

$token = ''

What line? What is wrong with it?

PHP Code:

class Newpassword extends CI_Controller {
  private $token = ''; 


You pass it to a method, but it's empty.

PHP Code:

// add()
    $token = $this->token;

    if ($this->Usermodel->set_new_password($token, $enc_password)) { 


PHP Code:

<?php echo form_open(base_url('newpassword/add')); ?>