How do I do negative form validation in the encoder?
is_unique
is a form validation that prevents the value from being used in the database. But can I do the opposite? for example, I would like to have a value that exists in the database, so I do the following rules:
$this->form_validation->set_rules('email', 'Email', 'required|max_length[32]|valid_email|(!(is_unique[users.email]))');
But this seems unfortunate as I expected, any recommendations? Thank you.
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You can do it like this:
$this->form_validation->set_rules('email', 'Email', 'required|max_length[32]|valid_email|callback_email_available');
Controller method
public function email_available($str)
{
// You can access $_POST variable
$this->load->model('mymodel');
$result = $this->mymodel->emailAvailability($_POST['email']);
if ($result)
{
$this->form_validation->set_message('email_available', 'The %s already exists');
return FALSE;
}else{
return TRUE;
}
}
The mymodel.php model
public function emailAvailability($email)
{
$this->db->where('email',$email);
$query = $this->db->get('tablename');
return $query->row();
}
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Extend the Form_validation library by adding a class MY_Form_validation.php
to your folder /application/core
(assuming your subclass prefix MY
matches the default). This is a quick example that simply inverts the existing is_unique
one by changing the last line from return $query->num_rows() === 0;
.
class MY_Form_validation extends Form_validation
{
/**
* Match one field to others
*
* @access public
* @param string
* @param field
* @return bool
*/
public function is_not_unique($str, $field)
{
list($table, $field)=explode('.', $field);
$query = $this->CI->db->limit(1)->get_where($table, array($field => $str));
return $query->num_rows() > 0;
}
}
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Try your own callback function
$this->form_validation->set_rules('email', 'Email', 'required|max_length[32]|valid_email|callback_email_check');
The function will be something like this
public function email_check($str)
{
if ($str == 'test@test.com')
{
$this->form_validation->set_message('email_check', 'The %s field can not be the word "test@test.com"');
return FALSE;
}
else
{
return TRUE;
}
}
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