Stop codeigniter from redirection - codeigniter

Question

Is it possible to make codeigniter not to redirect after a failed login attempt and show a message on the same login box.
My login box is a popup type, which appears after I have clicked on the login button and disappears after clicking on the background.
Controllers
public function login_validation() {
$this->load->library('form_validation');
$this->form_validation->set_rules('email','Email','required|trim|callback_validate_credentials');
$this->form_validation->set_rules('password','Password','required|md5');
if($this->form_validation->run()){
$data=array(
'email' => $this->input->post('email'),
'is_logged_in' => 1
);
$this->session->set_userdata($data);
redirect('site/members');
}else {
$this->main();
}
}
public function validate_credentials(){
$this->load->model('model_users');
if($this->model_users->can_log_in()){
echo 'success';
} else {
echo 'failed';
}
}
I was trying to change elses with error messages but it still redirected to another page.
Html:
<div id="login-box" class="login-popup">
<input id="username" name="email" value="" type="text" autocomplete="on" placeholder="Username">
<input id="password" name="password" value="" type="password" placeholder="Password">
<button name="login_submit" class="submitbutton" onclick="checkFormData()">Login</button>
</div>
<script>
function checkFormData(){
$.ajax({
type: "POST",
url: "<?php echo base_url(); ?>site/validate_credentials",
data: {
email: $("#email").val(),
password: $("#password").val()
},
success: function(response) {
if(response == 'success'){
location.href = 'site/members';
} else {
$("#errors").show();
}
}
});
}
</script>

Answer 1

If you want to have the alert in the modal, you'll want to check the data with ajax (javascript or jquery). For example you'd have something like this:
function checkFormData(){
$.ajax({
type: "POST",
url: "<?php echo base_url(); ?>your_controller/validate_credentials",
data: {
email: $("#email").val(),
password: $("#password).val()
},
success: function(response) {
if(response == 'success'){
location.href = <where you want to send them>;
} else {
$("#errors").show();
}
}
});
}
And your HTML would look something like:
<div class="hide" id="errors">Incorrect username/password.</div>
<input type="email" id="email" />
<input type="password" id="password" />
The class="hide" is meant to be something CSS related where you would have something like "display: none;".
Then in your controller you'd check like this:
if($this->model_users->can_log_in()){
echo 'success';
} else {
echo 'failed';
}
The echoed response is what will be sent to your ajax success function.
Edit:
You need to not use the form submission for the above to work, because with that method we don't want to submit the form, we want to pass the data from it.
<div id="login-box" class="login-popup">
<input id="username" name="email" value="" type="text" autocomplete="on" placeholder="Username">
<input id="password" name="password" value="" type="password" placeholder="Password">
<button name="login_submit" class="submitbutton" onclick="checkFormData()">Login</button>
</div>
I've also changed the javascript function above to be viewed as a function.

Answer 2

use
window.location.href = '/redirectpage'