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03-07-2012, 03:54 PM

[eluser]1cookie[/eluser]
hi

Ive been reading a book about design patterns (strategy) with PHP. I've got it working in native PHP like so:

Code:
&lt;?php

require 'class.lesson.php';

require 'class.coststratergy.php';

require 'class.timedcoststratergy.php';

require 'class.fixedcoststratergy.php';

require 'class.seminar.php';

require 'class.lecture.php';

$lessons[] = new Seminar( 4, new TimedCostStratergy() );

$lessons[] = new Lecture( 4, new FixedCostStratergy() );

foreach ( $lessons as $lesson ){

 print "lesson charge: {$lesson->cost()}";

 print " - charge type: {$lesson->chargeType()}.<br />\n";

 }

echo '<pre>';

var_dump($lessons);

echo '</pre>';

This prints:

Quote: lesson charge: 20 - charge type: Houly Rate.
lesson charge: 30 - charge type: Fixed Rate.

array(2) {
[0]=>
object(Seminar)#1 (2) {
["duration":"Lesson":private]=>
int(4)
["costStratergy":"Lesson":private]=>
object(TimedCostStratergy)#2 (0) {
}
}
[1]=>
object(Lecture)#3 (2) {
["duration":"Lesson":private]=>
int(4)
["costStratergy":"Lesson":private]=>
object(FixedCostStratergy)#4 (0) {
}
}
}

to the browser - correct output!

The trouble begins when I try to acheive the same thing in CI with:

Code:
//controller:

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

include ('/var/www/Composition/application/libraries/CostStrategy.php');

include ('/var/www/Composition/application/libraries/Lesson.php');

include ('/var/www/Composition/application/libraries/TimedCostStrategy.php');

include ('/var/www/Composition/application/libraries/FixedCostStrategy.php');

include ('/var/www/Composition/application/libraries/Lecture.php');

include ('/var/www/Composition/application/libraries/Seminar.php');

class Front extends CI_Controller {

 public function __construct()

 {

  parent::__construct();

 }

 public function index()

        {               

            $data['lessons'] = new Seminar( 4, new TimedCostStrategy() );

            $data['lessons'] = new Lecture( 4, new FixedCostStrategy() );

            $this->load->view('index', $data);

        }

}

Code:
//view:

<!DOCTYPE html>

&lt;html&gt;

    &lt;head&gt;

        &lt;title&gt;Composition with design patterns&lt;/title&gt;

        &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;

    &lt;/head&gt;

    &lt;body&gt;

        &lt;?php 

            foreach( $lessons as $lesson ){

                echo "lesson charge: {$lesson->cost()}.";

                echo "charge type: {$lesson->chargeType()}\n";

            }

            /*

             * Expecting:

             * lesson charge: 20. charge type: Hourly rate

             * lesson charge: 30. charge type: Fixed rate

             */

            echo '<pre>';

                var_dump($lesson->cost());

                 var_dump($lessons);

            echo '</pre>';

        ?&gt;

    &lt;/body&gt;

&lt;/html&gt;

The above prints:

Quote:A PHP Error was encountered

Severity: Notice

Message: Undefined variable: lesson

Filename: views/index.php

Line Number: 22

Fatal error: Call to a member function cost() on a non-object in /var/www/Composition/application/views/index.php on line 22

to the browser. A uml diagram can be seen

here

So in my codeigniter version

Code:
$lesson->cost()

$lesson is not an object?? And you need an instance to call a method right. I'm chasing my tail a bit right now?