CodeIgniter - File upload required validation

Question

I have 2 text fields and 1 file upload that are all required. Everything works when I require just the text fields, but when I require the file upload the validation error s

Answer 1

1. set a rule to check the file name (if the form is multipart)

   $this->form_validation->set_rules('upload_file[name]', 'Upload file', 'required', 'No upload image :(');

2. overwrite the $_POST array as follows:

   $_POST['upload_file'] = $_FILES['upload_file']

3. and then do:

   $this->form_validation->run()