full validations description of codeIgniter create a controller and load the form validation library and helper form and url.
$this->load->helper(array("form","url"));
$this->load->library('form_validation');
and load your view. ####In view create a html form
<form class="form-basic" method="post">
<input type="text" name="name">
<input type="text" name="email">
</form>
and set rules for validate your form in controller
$this->form_validation->set_rules('name', 'name', 'required');
$this->form_validation->set_rules('email', 'email', 'required|valid_email');
Run validations rule by
if ($this->form_validation->run() == FALSE){
$this->pageData["from_status"] = "Form successfully validated";
}
To show the errors, there are a default function by codeigniter validation_errors() . Call this function in your view file.