Learn CODEIGNITER with Real Code Examples

<?php

// application/controllers/Counter.php
class Counter extends CI_Controller {
    public function __construct() {
        parent::__construct();
        $this->load->library('session');
        if (!$this->session->has_userdata('count')) {
        $this->session->set_userdata('count', 0);
        }
    }

    public function index() {
        $count = $this->session->userdata('count');
        echo "<h2>Counter: $count</h2>";
        echo "<form method='post' action='/counter/increment'><button type='submit'>+</button></form>";
        echo "<form method='post' action='/counter/decrement'><button type='submit'>-</button></form>";
        echo "<form method='post' action='/counter/reset'><button type='submit'>Reset</button></form>";
    }

    public function increment() {
        $count = $this->session->userdata('count') + 1;
        $this->session->set_userdata('count', $count);
        redirect('/counter');
    }

    public function decrement() {
        $count = $this->session->userdata('count') - 1;
        $this->session->set_userdata('count', $count);
        redirect('/counter');
    }

    public function reset() {
        $this->session->set_userdata('count', 0);
        redirect('/counter');
    }
}

Demonstrates a simple CodeIgniter controller and routes for a counter using session for state persistence.