CodeIgniter form_validation->run() always returns false?

I think this is happening because you have not set any validation rules.Controller code should look like this:

public function write_prof_review($prof_id){    $this->load->model('Queries');    // form stuff here    $this->load->helper('form');    $this->load->library('form_validation');    $data['prof_id'] = $prof_id;    // here it is; I am binding rules     $this->form_validation->set_rules('course_code', 'Course Code', 'required');    $this->form_validation->set_rules('easiness', 'easiness', 'required');    $this->form_validation->set_rules('helpfulness', 'helpfulness', 'required');    if($this->form_validation->run() == FALSE) {        $this->load->view('create_prof_review', $data);    }    else {        $this->Queries->submit_prof_review($prof_id, $this->USERID);        $this->load->view('form_submitted');    }}

Please refer to the CodeIgniter user guide; it will give you more information about validation rules.

I had the same problem though the cause was different. I was missing one of the input fields that I was validating from the form i.e

private function validate_data(){        $validate_data = array(            array(                'field' => 'steps',                'label' => 'Steps',                'rules' => 'trim|required|integer|xss_clean'            ),            array(                'field' => 'pace',                'label' => 'Pace',                'rules' => 'trim|required|integer|xss_clean'            ),            array(                'field' => 'speed',                'label' => 'Speed',                'rules' => 'trim|required|numeric|xss_clean'            ),            array(                'field' => 'distance',                'label' => 'Distance',                'rules' => 'trim|required|numeric|xss_clean'            )        );//end array validate_data        return $validate_data;  }

I was missing the speed input field in the form. I added it and the problem was solved. It really gave me a headache cause I was just reusing code that I have used so many times, so I could not understand why ($this->form_validation->run() was returning false, something that I had never experienced before.

You can go to system/library/Form_validation.php

and in

if (count($this->_config_rules) == 0){return FALSE;}

change false to true