Question

Say I have a login form in CodeIgniter — I can set validation rules for individual inputs, but is there a way to throw a model/controller level error and a message?

Specifically, if the below method does not return TRUE, I want my form to re-display with the message “The email address or password is incorrect”. Currently the controller just reloads the view and the set_value()s

public function authorize_user()
{
    $this->db->where('email', $this->input->post('email'));
    $this->db->where('password', $this->input->post('password'));

    $q = $this->db->get('users');

    if($q->num_rows() == 1){
        return true;
    }
}

Perhaps I’m overthinking this and I should just attach that error message to the email input?

Answer 1

You can use a callback function to accomplish this. The steps are as follow:
1. Your authorize_user() function must be in the controller you set the rules.
2. You make a “callback” rule by adding a code similar to:

$this->form_validation->set_rules('email', 'email', 'callback_authorize_user['.$this->input->post("password").']');

Note that I added a parameter for the callback function. These kind of functions automatically receive a parameter which is determined by the first argument of set_rules(). In this case, the argument passed automatically to the callback function is the email. Aditionally, I pass the password as second parameter.

3.Add the respective parameters to your function:

public function authorize_user($email,$password)
{
   //As I said before, the email is passed automatically cause you set the rule over the email field.
    $this->db->where('email', $email);
    $this->db->where('password', $password);

    $q = $this->db->get('users');

    if($q->num_rows() == 1){
        return true;
    }
}

More info at: http://codeigniter.com/user_guide/libraries/form_validation.html#callbacks

Hope it helps!