How can I do this without breaking the MVC framework in CakePHP?

Question

Sorry for what is a generic title. I'm not the best at titles.

Anyway the way Cake passes around data (as a hash) is pretty much the reason why I even need to ask this question. If when I passed a variable/obj from the controller to the view, it was an object that I can ask questions to (i.e. $duck->quack() ) rather than having it be an array/dictionary (i.e. $duck['Duck']['quack'] == true) this would be easy.

What I have in my app is a list of items that a user x can own or not. In certain views I display all the items in the database/app (i.e. paginate) and for each item I need to know if the logged in user owns it or not. To answer this question I need to do a query (due to a complicated HABTM relationship), which is done inside the Model. In other words my Item model has a function isOwnedByUser($user_id, $item_id) which is true if it is owned by user. I want to call this function from the view.

Naturally this is violating the MVC framework, but I'm not sure how else to do it. I had four ideas:

Idea 1:

Do this inside a helper:

App:Import('Model','Item');
$item = new Item();
$item->isOwnedByUser($user_id,$item_id);

and call the helper from the view (and pass in the $item_id and $user_id of course). But this REALLY violates the MVC framework.

Idea 2:

Create a action inside item_controller.php and call the action from the view using requestAction(). But I heard that this was extremeley inefficent

Now these two ideas I found when I was looking for a solution to my problem but according to them those two ideas are bad so I came up with two more solutions:

Idea 3:

When returning the paginated data to the view, I can make sure that all items have a 'user_id' key so that I can check the key in the view against the logged in user's id to see if he/she owns item. But this would require a) me to re-write pagination b) very ugly queries especially for certain views (search), c) overall ugliness and slowness. So I decided to abandon this idea

Idea 4:

Every time a view needs to know if an item is owned by user, I'll just pass along another array from the controller that contains ALL the items a user owns and in the view you can just use in_array() to check if user owns said item. Of course the problem to this is obvious: what if the user has lots of items?

In short I'm stuck at this and I have no clue where to go from here and I'd appreciate all help! Thanks!

Answer 1

I'd combine 3 and 4.

In your action, after you get all the paginated items:

$items = $this->paginate('Item');

Get their IDs and combine that with the user ID to fetch all the user's items.

$itemIds = Set::extract('/Item/id', $items);

$usersItems = $this->Item->User->find
    (
     'all',
     array
     (
      'conditions' => array
      (
       'User.id' = $userId,
       'Item.id' => $itemIds
      ),
      'fields' => array('User.id', 'Item.id')
     )
);

Now you can set the $usersItems in a format you prefer and set both that and $items for the view. That would bring you to your option 4 and in_array(), except it would probably be Set::extract() or Set::check().

Something like this should do it:

if (Set::extract(sprintf('/Item[id=%s]', $itemId), $usersItems))
{
    // user has the item
}

(I wrote this from my memory so... you know what to do if it fails :))

Edit:

Alternatively, you can do something like this (it should be faster than the above, just make sure to move Set::extract() out of the loop):

$usersItemIds = Set::extract('/Item/id', $usersItems);

if (in_array($itemId, $usersItemIds))
{
    // user has the item
}

Answer 2

I know this is an old question, but it seems like maybe the ACL component would be a good option here.