The form validation library seems to only work on POST. I need to use query strings and would like to use CI to validate the passed values. Is there a way to do this?
Reference How do I validate a form field in Codeigniter when using Get parameters?
Before validation rules, set the validation data with the following code.
$this->form_validation->set_data($_GET);
The current Codeigniter 3.0 development branch provides an option to insert your own variable instead of $_POST. So you could start using 3.0.
Alternatively, the only way in CI2.1 is to do $_POST=$_GET before you run the validation.
You could overwrite the Form_validation function run in a MY_Form_Validation and modify it.
See this page for the CodeIgniter 3 solution:- http://www.codeigniter.com/userguide3/libraries/form_validation.html#validating-an-array-other-than-post
For CodeIgniter 2 you can do $_POST = $_GET; before $this->form_validation->run() as mentioned above.