Unable to access an error message - Callback validation in CodeIgniter - php

Question

I have simple code thats not working. I made validation for checkbox and I get error:
Unable to access an error message corresponding to your field name accept_terms_checkbox.(accept_terms)
This is my code:
Controller:
public function formularz2()
{
$this->load->helper(array('form', 'url'));
$this->load->library('form_validation');
$data['szkolenia'] = $this->Szkolenie_m->pobierz();
//VALIDATION!!
$this->form_validation->set_rules('imie', 'Imię', 'required');
$this->form_validation->set_message('required', 'Błąd: wypełnij powyższe pole');
$this->form_validation->set_rules('accept_terms_checkbox', 'checkbox', 'callback_accept_terms');
//CALLBACK FUNCTION!!
function accept_terms()
{
if ($this->input->post('accept_terms_checkbox'))
{
return TRUE;
}
else
{
$error = 'Please read and accept our terms and conditions.';
$this->form_validation->set_message('accept_terms', $error);
return FALSE;
}
}
//Po przesłaniu danych
if (!empty($_POST))
{
$konsultant = $this->uri->segment(3);
$dane = array(
'email1' => $this->input->post('email'),
'imie' => $this->input->post('imie'),
'nazwisko' => $this->input->post('nazwisko'),
'nazwa_firmy' => $this->input->post('firma'),
'konsultant_id' => $konsultant,
);
//Trzeba jeszcze tutaj ogarnąć wrzucanie pivotów zaznaczonych checkboxów
$boxes = $_POST['formChecks'];
$N = count($boxes);
$ostatni_id = $this->Osoby_m->ostatni_id();
for($i=0; $i < $N; $i++)
{
$this->Osoby_m->nowy_wpis_formularz($boxes[$i]);
}
//Pobrać id dodanej osoby = policzyć ile osób w bazie +1
$this->Osoby_m->nowa_osoba($dane);
}
if ($this->form_validation->run() == FALSE)
{
$this->load->view('formularz', $data);
}
else
{
$this->load->view('wyslano_formularz');
}
}
My View:
<?php echo form_open(); ?>
<div class="form-group">
<label for="email" class="col-sm-2 control-label">Email:</label>
<div class="col-sm-10">
<input type="email" class="form-control" id="email" name="email" placeholder="Email" value="<?php echo set_value('email'); ?>">
<p class="help-block"><?php echo form_error('email'); ?></p>
</div>
</div>
<div class="form-group">
<label for="imie" class="col-sm-2 control-label">Imię:</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="imie" name="imie" placeholder="Imię" value="<?php echo set_value('imie'); ?>">
<p class="help-block"><?php echo form_error('imie'); ?></p>
</div>
</div>
<div class="form-group">
<label for="nazwisko" class="col-sm-2 control-label">Nazwisko: </label>
<div class="col-sm-10">
<input type="text" class="form-control" id="nazwisko" name="nazwisko" placeholder="Nazwisko" value="<?php echo set_value('nazwisko'); ?>">
<p class="help-block"><?php echo form_error('nazwisko'); ?></p>
</div>
</div>
<div class="form-group">
<label for="firma" class="col-sm-2 control-label">Firma:</label>
<div class="col-sm-10">
<input type="text" class="form-control" id="firma" name="firma" placeholder="Firma" value="<?php echo set_value('firma'); ?>">
<p class="help-block"><?php echo form_error('firma'); ?></p>
</div>
</div>
<div class="col-sm-12" style="margin-bottom: 30px; margin-top: 30px;"> <h3>Wybierz interesujące Cię szkolenia</h3></div>
<div class="form-group">
<label class="col-sm-2 control-label">Szkolenia:</label>
<div class="col-sm-10">
<?php foreach ($szkolenia as $szkolenie): ?>
<div class="checkbox">
<label><input id="szkolenie<?php echo $szkolenie->id; ?>" type="checkbox" name="formChecks[]" value="<?php echo $szkolenie->id; ?>"> <?php echo $szkolenie->nazwa_szkolenia; ?></label>
<br>
</div>
<?php endforeach; ?>
</div>
</div>
//CALLBACK CHECKBOX
<div class="form-group">
<div class="col-sm-12" style="margin-top: 50px;">
<input type="checkbox" name="accept_terms_checkbox" value="1"/> Zgadzam się na otrzymywanie maili od firmy Gamma<br>
<p><?php echo form_error('accept_terms_checkbox') ?></p>
</div>
</div>
<button type="submit" class="btn btn-lg btn-success" style="margin-top: 50px;">Odbierz Voucher</button>
<?php echo form_close(); ?>

Answer 1

In order to use your own callback method with codeigniter's validation class, you must declare the method. IN your case ( add this to your controller or a helper etc...):
public function accept_terms($user_input){
if($user_input != ""){
return True;
}else{
$this->form_validation->set_message('accept_terms_checkbo', 'The %s field can not be empty"');
return False;
}

Answer 2

I fixed this error by simple validation without callback function. I figure out that I don't need callback function for Terms of Services checkbox.
$this->form_validation->set_rules('accept_terms_checkbox', 'Checkbox', 'required');
$this->form_validation->set_message('required', 'You need to accept Terms of Services');