In codeigniter controller is not being called and its giving a blank page

Question

I have got many blogs. I have tried to find a solution why controller is not loading the page and displaying a blank page . But I would not find it useful. But the code works fine in localhost. I don't know why it is so. Unable find a solution. Any help would be appreciated.

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Config_test extends CI_Controller {

public function __construct(){
    parent::__construct();

    if( $this->session->userdata('logged_in') != TRUE ){
        redirect('login?reurl='.current_url());
    }elseif (!$this->usergroup_model->page_allowed()) {
        //This check will ensure that only authorised users can have access to any 
        //functions present in this controller
        //Route all control requests only through config function only
        show_error('The url is either wrong or the inputs are inadquate. Please navigate with the help of menu bar only...');
        die();
    }

    $this->moduleID = '3';
    $this->menu['main_menus'] = $this->usergroup_model->menu_access();
    $this->menu['sub_menus'] = $this->usergroup_model->submenu_access($this->moduleID);
    $this->menu['module_name'] = $this->usergroup_model->module_name($this->moduleID);
    $this->load->vars($this->menu);

    $this->load->model('model_1');
    $this->load->model('model_2');
    $this->load->model('model_3');
}

function index(){
    $this->config();
}

function config($action=null)
{
    //If customer ID is null... redirect to dashboard...        
    if($this->session->userdata('dashboard_customer_id') == null)
        redirect('dashboard');

    switch ($action) 
    {
        case 'add':
            $this->add();
            break;
        case 'add_save':
            $this->add_save();
            break;
        case 'add_success':
            $this->add_success();
            break;
        case 'edit':
            $this->edit();
            break;
        case 'edit_save':
            $this->edit_save();
            break;
        case 'edit_success':
            $this->edit_success();
            break;
        default:
            $this->edit();
            break;
    }
}

function add()
{
    //doing some function 
}

function add_save()
{
    //some code 
}

function add_success()
{
    //some code
}

function edit()
{
    //some code
}

function edit_save()
{
    //some code 
}

function edit_success()
{
    //Not used here...
}   

} 

And this is my url http://localhost/tester/index.php/Config_test

Answer 1

May be mod_rewrite is not enabled on server.

enable mod_rewrite on server

Answer 2

The problem can be caused by many thinks like a missing extension of php. Have you looked into error logs. Maybe if you provide some more info I can be able to help you. What is the version of php you are using in localhost and the live system.

Answer 3

Apache is case-sensitive by default, so:

http://localhost/tester/index.php/Config_test

should be lowercase:

http://localhost/tester/index.php/config_test

Of course, keep the controller class name capitalized.