Non-public accessible function in CakePHP - php

Question

I have built a simple Notification system in my Cake app that I want to have a function that will create a new notification when I call a certain method. Because this is not something the user would actually access directly and is only database logic I have put it in the Notification model like so:
class Notification extends AppModel
{
public $name = 'Notification';
public function createNotification($userId, $content, $url)
{
$this->create();
$this->request->data['Notification']['user_id'] = $userId;
$this->request->data['Notification']['content'] = $content;
$this->request->data['Notification']['url'] = $url;
$result = $this->save($this->request->data);
if ($result)
{
$this->saveField('datetime', date('Y-m-d H:i:s'));
$this->saveField('status', 0);
}
}
}
And then whenever I want to create a notification within my app I just do:
$this->Notification->createNotification($userId,'Test','Test');
However this doesn't work! The controller is talking to the model fine, but it doesn't create the row in the database... I'm not sure why... but it would seem I'm doing this wrong by just doing all the code in the model and then calling it across the app.
Edit: Based on answers and comments below, I have tried the following the code to create a protected method in my notifications controller:
protected function _createNotification($userId, $content, $url)
{
$this->Notification->create();
$this->request->data['Notification']['user_id'] = $userId;
$this->request->data['Notification']['content'] = $content;
$this->request->data['Notification']['url'] = $url;
$result = $this->save($this->request->data);
if ($result)
{
$this->saveField('datetime', date('Y-m-d H:i:s'));
$this->saveField('status', 0);
}
}
Now the thing that is stumping me still (apologies if this is quite simple to others, but I have not used protected methods in CakePHP before) is how do I then call this from another controller? So for example If have a method in my PostsController and want to create a notification on successful save, how would I do this?
I thought about in my PostsController add method:
if($this->save($this->request-data){
$this->Notification->_createNotification($userId,'Test','Test');
}
But being protected I wouldn't be able to access the method from outside of the NotificationsController. Also I'm using the same syntax as if I was calling a function from a model so again it doesn't feel right.
Hopefully someone can help me out and get me back on track as this is a new area to me.

Answer 1

the controller should pass all data to the model
$this->createNotification($this->request->data);
the model then can use the data:
public function createNotification(array $data) {
$key = $data[$this->alias]['key'];
$data[...] = ...;
$this->create();
return $this->save($data);
}
you never ever try to access the controller (and/or its request object) from within a model.
you can also invoke the method from other models, of course:
public function otherModelsMethod() {
$this->Notification = ClassRegistry::init('Notification');
$data = array(
'Notification' => array(...)
);
$this->Notification->createNotification($data);
}
and you can make your methods verbose, but that usually makes it harder to read/understand/maintain with more and more arguments:
public function createNotification($userId, $content, $url) {
$data = array();
// assign the vars to $data
$data['user_id'] = $userId;
...
$this->create();
return $this->save($data);
}
so this is often not the cake way..

Answer 2

Methods in a model are not "publicly accessible" by definition. A user cannot call or invoke a method in a model. A user can only cause a controller action to be initiated, never anything in the model. If you don't call your model method from any controller, it's never going to be invoked. So forget about the "non-public" part of the question.
Your problem is that you're working in the model as if you were in a controller. There is no request object in a model. You just pass a data array into the model method and save that array. No need for $this->request. Just make a regular array(), put the data that was passed by the controller in there and save it.

Answer 3

The whole approach is totally wrong in the MVC context IMO and screams for the use of the CakePHP event system. Because what you want is in fact trigger some kind of event. Read http://book.cakephp.org/2.0/en/core-libraries/events.html
Trigger an Event and attach a global event listener that will listen for this kind of events and execute whatever it should do (save something to db) when an event happens. It's clean, flexible and extendible.
If you did a proper MVC stack for your app most, if not all, events aka notifications should be fired from within a model like when a post was saved successfully for example.

Answer 4

This is what I have ended up doing. While it certainly isn't glamorous. It works for what I want it to do and is a nice quick win as the notifications are only used in a few methods so I'm not creating a large amount of code that needs improving in the future.
First to create a notification I do the following:
$notificationContent = '<strong>'.$user['User']['username'].'</strong> has requested to be friends with you.';
$notificationUrl = Router::url(array('controller'=>'friends','action'=>'requests'));
$this->Notification->createNotification($friendId,$notificationContent,$notificationUrl);
Here I pass the content I want and the URL where the user can do something, in this case see the friend request they have been notified about. The url can be null if it's an information only notification.
The createNotification function is in the model only and looks like:
public function createNotification($userId, $content, $url = null)
{
$this->saveField('user_id',$userId);
$this->saveField('content',$content);
$this->saveField('url',$url);
$this->saveField('datetime', date('Y-m-d H:i:s'));
$this->saveField('status', 0);
}
This creates a new record in the table with the passed content, sets its status to 0 (which means unread) and the date it was created. The notification is then set as read when a user visits the notifications page.
Again this is most probably not an ideal solution to the problem outlined in this question... but it works and is easy to work with And may prove useful to others who are learning CakePHP who want to run functions from models when building prototype apps.
Remember nothing to stop you improving things in the future!

Answer 5

First of all, you can improve your last solution to do one save() (instead of 5) the following way:
public function createNotification($userId, $content, $url = null){
$data = array(
'user_id' => $userId,
'content' => $content,
'url' => $url,
'datetime' => date('Y-m-d H:i:s'),
'status' => 0
);
$this->create();
$this->save($data);
}
When I began programming CakePHP(1.3) more than a year ago I also had this problem.
(I wanted to use a function of a controller in any other controller.)
Because I didn't know/researched where to place code like this I've done it wrong for over a year in a very big project. Because the project is really really big I decided to leave it that way. This is what i do:
I add a function (without a view, underscored) to the app_controller.php:
class AppController extends Controller {
//........begin of controller..... skipped here
function _doSomething(){
//don't forget to load the used model
$this->loadModel('Notification');
//do ur magic (save or delete or find ;) )
$tadaaa = $this->Notification->find('first');
//return something
return $tadaaa;
}
}
This way you can access the function from your Notification controller and your Posts controller with:
$this->_doSomething();
I use this kind of functions to do things that have nothing to do with data submittance or reading, so i decided to keep them in the app_controller. In my project these functions are used to submit e-mails to users for example.. or post user actions to facebook from different controllers.
Hope I could make someone happy with this ;) but if you're planning to make a lot of these functions, it would be much better to place them in the model!