CakePHP call to member function on non-object - cakephp

Question

I have the following Model and Controller files, and when i visit this url, http://....../pois/index i get this error:
Notice (8): Undefined property: PoisController::$Poi [APP/controllers/pois_controller.php, line 5]
Fatal error: Call to a member function find() on a non-object in /home/joecoyle/public_html/app/controllers/pois_controller.php on line 5
The Model is this, called poi.php:
<?php
class Poi extends AppModel {
}
?>
And the controller is this, named pois_controller.php
<?php
class PoisController extends AppController {
function index(){
$this->set('pois',$this->Poi->find('all'));
}
}
?>
As i am new to CakePHP i am not sure what is causing this error, as everything seems to be named, right, and i am following the tutorial on the CakePHP site...
Thanks

Answer 1

You need add var $name = "Poi"; to initialize your class in the controller.
And I've tested that in PHP5.It seems that this is necessary.
Edit:
controller file name:pois_controller.php,code:
<?php
class PoisController extends AppController
{
var $name = "Poi";
function index()
{
debug($this->Poi);
exit;
}
}
?>
database name:pois.Structure:id ,name
And using /pois/ will got:
Poi Object
(
[name] => Poi
[useDbConfig] => default
[useTable] => pois
[displayField] => name
[id] =>
[data] => Array
(
)
[table] => pois
[primaryKey] => id
[_schema] => Array
(
[id] => Array
(
[type] => integer
[null] =>
[default] =>
[length] => 11
[key] => primary
)
[name] => Array
(
[type] => integer
[null] =>
[default] =>
[length] => 11
)
...etc

Answer 2

If SpawnCxy's solution doesn't do the job (my own controllers set the name property to the pluralized version rather than the singular variation that the model takes), take a look at the inflection. "Poi" isn't a "common" word and a quick test tells me that CakePHP 1.2.6 doesn't handle this word the way you're thinking it will:
echo '<p>' . Inflector::singularize( 'Pois' ) . '</p>'; # prints "Pois"
echo '<p>' . Inflector::pluralize( 'Poi' ) . '</p>'; # prints "Pois"
The point of this, of course, is that Cake may not be making the correct association between the PoisController (plural) and the Poi model (singular) the way it does for most common English names.

Answer 3

An alternative to adapting your code to Cake's pluralising/singularising rules is the converse: adapting Cake's rules to your code:
In app/config/inflections.php, find the $irregularPlural line, and change it to:
$irregularPlural = array('poi'=>'pois');
This will instruct Cake to treat the singular of "Pois" as "Poi."
This is a good choice when changing the inflection rules creates better readability/comprehensibility of the rest of your code. For example, by default, Cake treats the singular of "News" as "New". However, it made more sense to find news items with $this->News->find than $this->New->find, so I tweaked the inflection rules.

Answer 4

It's a problem because $this->Poi has not been initialized as an object. I'm not familiar with CakePHP, but in your init function in the PoisController or in contructor you should call $this->Poi = new Poi(); so in the index action when you try to call find(), the method will be called on an instance of Poi model.