PHP works locally, not on server

Question

I've been developing a custom CMS using Codeigniter locally and I've just gotten to the point where I need to upload it to a staging server to do some more testing.

Everything works except for the sidebar section of the site that uses a widget system. I initially thought it was just differences between PHP versions, as I am running 5.4.4 locally and the server was 5.3. After upgrading the server to 5.4.7, the sidebar is still not appearing. I get no error, just nothing displays.

This is the Widget library code:

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

class Widgets {

    private $_ci;
    protected $parser_enable = FALSE;

    public function __construct() {
        $this->widgets();
    }

    public function widgets(){
        $this->_ci =& get_instance();
    }

    public function build($view,$data=array()){
        $view = get_class($this).'/'.$view;
        $subdir = '';
        if (strpos($view, '/') !== FALSE)
        {
                // explode the path so we can separate the filename from the path
                $x = explode('/', $view);

                // Reset the $class variable now that we know the actual filename
                $view = end($x);

                // Kill the filename from the array
                unset($x[count($x)-1]);

                // Glue the path back together, sans filename
                $subdir = implode($x, '/').'/';
        }

        $widget_view = APPPATH.'widgets/'.$subdir.'views/'.$view.EXT;

        if(file_exists($widget_view)){
            $widget_view = '../widgets/'.$subdir.'views/'.$view.EXT;
            if($this->parser_enable){
                $this->_ci->load->library('parser');
               return $this->_ci->parser->parse($widget_view,$data,TRUE);
            }
            else{
                return $this->_ci->load->view($widget_view,$data,TRUE);
            }
        }

        return FALSE;
    }

    public function __get($var) {
        static $ci;
        isset($ci) OR $ci = get_instance();
        return $ci->$var;
    }
}

Does anything jump out that could cause it not to display?

Is there anything I should be looking at to make it compatible, such as server modules? What on the server could be affecting this?

EDIT:

I have the widgets residing in the following path:

/public_html/application/widgets/recent_news/views/view.php

The $widget_view = 'widgets/'.$subdir.'views/'.$view.EXT; variable is returning widgets/Recent_news/views/view.php which is getting passed to:

if(file_exists($widget_view)){
    return $this->_ci->load->view($widget_view,$data,TRUE);
}

The application path in $widget_view doesn't seem to be correct on the staging server, so file_exists() returns false and doesn't load the view (which would have an incorrect path anyways).

I just can't seem to make it read the correct path, any suggestions?

Answer 1

If it's a staging server, go into the php.ini file and set

error_reporting = E_ALL | E_STRICT
display_errors = On

This will output whatever errors it finds so you can debug it.

Answer 2

Ended up just needing to subdir = strtolower($subdir);

Thanks for the help everyone