codeigniter help causing error while loading model - codeigniter

Question

I am not sure whats wrong with my code.......it causing an error while loading model.......
please help...........
my controller
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Exams extends CI_Controller {
public function index(){
$ob = new exam_class();
$ob->set_exam(0,'Html exam','1','20');
$ob->create_exam();
echo 'success';
}
}
class exam_class{
private $id;
private $title;
private $catagory;
private $timeLength;
function set_exam($id,$title,$catagory,$timeLength){
$this->id = $id;
$this->title = $title;
$this->catagory = $catagory;
$this->timeLength = $timeLength;
}
function create_exam(){
$this->load->model('examModel');
$this->examModel->create_exams($title,$catagory,$timeLength);
}
}
model
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class ExamModel extends CI_Model {
public function create_exams($title,$catagory,$timeLength){
$data = array(
'title' => $title ,
'catagory' => $catagory ,
'timeLength' => $timeLength
);
$this->db->insert('exams', $data);
}
}
error
A PHP Error was encountered
Severity: Notice
Message: Undefined property: exam_class::$load
Filename: controllers/exams.php
Line Number: 26
Fatal error: Call to a member function model() on a non-object in C:\xampp\htdocs\exam\application\controllers\exams.php on line 26

Answer 1

You shouldn't put more than one class in a file. Controller should be something like this.
class Exams extends CI_Controller {
private $id;
private $title;
private $catagory;
private $timeLength;
public function __construct()
{
parent::__construct();
$this->load->model('examModel');
}
public function index(){
$this->set_exam(0,'Html exam','1','20');
$this->create_exam();
echo 'success';
}
function set_exam($id,$title,$catagory,$timeLength){
$this->id = $id;
$this->title = $title;
$this->catagory = $catagory;
$this->timeLength = $timeLength;
}
function create_exam(){
$this->examModel->create_exams($title,$catagory,$timeLength);
}
}

Answer 2

Along with #shin i want to include that go to this file
....\testproject\application\config\autoload.php
and edit this to add your models
$autoload['model'] = array('modelName1','modelName2');
and to load the models from any time from any controller . This will automatically load your models.No need to add
$this->load->model('modelName');

Answer 3

Tip : Keep it simple
In your controller :
public function __construct()
{
parent::__construct();
$this->load->model('examModel');
}
public function index()
{
$exam_data = $this->process_exam_data(0,'Html exam','1','20');
$insert_status = $this->examModel->create_exams($exam_data);
if($insert_status===TRUE){
echo "Exam Insert Successful!";
}
else{
echo "Exam Insert Failed";
}
}
public function process_exam_data($id, $title, $category, $timelength)
{
// Do whatever you want with the data, calculations etc.
// Prepare your data array same as to be inserted into db
$final_data = array(
'title' => $processed_title,
'catagory' => $processed_category,
'timeLength' => $processed_time
);
return $final_data;
}
And in your model :
public function create_exams($data)
{
$result = $this->db->insert('exams', $data); // Query builder functions return true on success and false on failure
return $result;
}
Your index function is the main function which does the calling, whereas all the processing work is done in the process_exam_data function.
Have a nice day :)