Check if db row has specific values - mysql

Question

I am creating an event, each event will have attendees, I got this working fine, the problem I am having is an attendee can attend the same event twice, which is not good.
Event View
<?php if($this->session->userdata('user_id')): ?>
<hr>
<?php echo form_open('/attendees/add/'.$event['id']); ?>
<input type="hidden" name="user_id" value="<?php echo $_SESSION['user_id']; ?>">
<input type="submit" value="I'm in!" class="btn btn-success">
</form>
<?php endif; ?>
Attendees Controller
<?php
class Attendees extends CI_Controller {
public function add($event_id) {
// Check login
if(!$this->session->userdata('logged_in')){
redirect('users/login');
}
$this->form_validation->set_rules('user_id', 'required|callback_check_userid_eventid');
if($this->form_validation->run() === FALSE){
$this->session->set_flashdata('attendee_not_added', 'You are already on the list.');
redirect('home');
} else {
$this->attendee_model->add_attendee($event_id);
// Set message
$this->session->set_flashdata('attendee_added', 'You have been added to this event.');
redirect('events');
}
}
}
Attendees Model
<?php
class Attendee_model extends CI_Model {
public function __contruct() {
}
public function get_attendees($id = FALSE){
if($id === FALSE) {
$query = $this->db->get('attendees');
return $query->result_array();
}
$this->db->select('attendees.id, attendees.team, attendees.is_goalie, event.id, user.first_name, user.last_name');
$this->db->from('attendees');
$this->db->join('event', 'attendees.event_id = event.id', 'inner');
$this->db->join('user', 'attendees.user_id = user.id', 'inner');
$this->db->where('event.id', $id);
$query = $this->db->get();
return $query->row_array();
}
public function add_attendee($event_id){
$data = array(
'event_id' => $event_id,
'user_id' => $this->session->userdata('user_id')
);
return $this->db->insert('attendees', $data);
}
// Check attendee exists in event
public function check_userid_eventid($event_id, $user_id){
$query = $this->db->get_where('attendees', array('user_id' => $user_id, 'event_id' => $event_id));
if(empty($query->row_array())){
return true;
} else {
return false;
}
}
}
As you can see I tried creating a custom callback on the button form validation but it did not work.
If anyone can point me in the right direction, let me know if I am even somewhat close.
Thanks in advance.

Answer 1

You are not passing the $event_id value to the callback function. Replace your validation with the following line
$this->form_validation->set_rules('user_id', 'User ID', 'required|callback_check_userid_eventid['.$event_id.']');
add following callback function inside the Attendees Controller file
public function check_userid_eventid($user_id, $event_id){
$CI =& get_instance();
$CI->load->database();
$CI->form_validation->set_message('user_id_unique', "Sorry, that %s is already being used.");
return isset($CI->db) ? ($CI->db->limit(1)->get_where('attendees',compact('user_id','event_id'))->num_rows() == 0) : false;
}

Answer 2

Your callback is in a model that form validation knows nothing about. If you look at the docs: callbacks should be in the same controller as the form validation method that uses it.
However, you can use a function in a model as a callback with a different syntax:
$this->form_validation->set_rules(
'username', 'Username',
array(
'required',
array($this->users_model, 'valid_username')
)
);
as documented here.
Finally, on a false return, you need to make sure that you are setting a message as seen in this example:
public function username_check($str)
{
if ($str == 'test')
{
$this->form_validation->set_message('username_check', 'The {field} field can not be the word "test"');
return FALSE;
}
else
{
return TRUE;
}
}
In conclusion: the documentation has all the answers.

Answer 3

Put the call back function into Controller
<?php
class Attendees extends CI_Controller {
public function add($event_id) {
// Check login
if(!$this->session->userdata('logged_in')){
redirect('users/login');
}
$this->form_validation->set_rules('user_id', 'required|callback_check_userid_eventid');
if($this->form_validation->run() === FALSE){
$this->session->set_flashdata('attendee_not_added', 'You are already on the list.');
redirect('home');
} else {
$this->attendee_model->add_attendee($event_id);
// Set message
$this->session->set_flashdata('attendee_added', 'You have been added to this event.');
redirect('events');
}
}
// Check attendee exists in event
public function check_userid_eventid($event_id, $user_id){
$query = $this->db->get_where('attendees', array('user_id' => $user_id, 'event_id' => $event_id));
if(empty($query->row_array())){
return true;
} else {
return false;
}
}
}