Model Bouncing - Best Practices?

[eluser]darioism[/eluser]
Didn't want to use the word "looping", but don't know what else to call it.

Let's say I have the following model:

Code:

$car_info = $this->cars->get($car_id);

I would design it to return an object with details about the car, and details about the manufacturer.

Then I also have the following model:

Code:

$manufacturer_info = $this->manufacturers->get($manufacturer_id);

I would design this to return an object of details about the manufacturer, and an array of cars produced by that manufacturer, with details of each car as an object.

The problem is, these models overlap and loop back and forth upon themselves, as they try to obtain information about each other's information. What would be a best practice as far as design in this case, and is there a programming term for this predicament? Thanks.

[eluser]WanWizard[/eluser]
You have to stop the recursion in your code.

You could do that with a second parameter (for example a boolean) for one of the two method calls, instructing the method not to dig deeper.

for example, if you call $this->car-get() from the manufacturers model, you allready know the manufacturer. So use the second parameter to indicate you only want car info, and no manufacturer details.

[eluser]darioism[/eluser]
Thanks for the reply.

I was hoping there was a more complex way of detecting this recursion or an advanced programming technique that I don't know about yet for architecting a solution. If not, the boolean approach is of course a good solution, but I like to have as few switches as possible in my code for simplicity. Maybe I'm overthinking it?

[eluser]WanWizard[/eluser]
You could do things dynamically by walking up the object chain ( this -> parent -> grandparent -> ... ) and check if the class object you are about to create is already present further up the chain.

Which is a lot of code, and is going to slow your application down considerably. Sometimes KISS is the best approach, if something sounds complex, it usually is...

[eluser]Nick_MyShuitings[/eluser]
[quote author="darioism" date="1283617090"]Thanks for the reply.

I was hoping there was a more complex way of detecting this recursion or an advanced programming technique that I don't know about yet for architecting a solution. If not, the boolean approach is of course a good solution, but I like to have as few switches as possible in my code for simplicity. Maybe I'm overthinking it?[/quote]

From the way you are thinking, it sounds like an ORM is what you are looking for. There are a few written specifically for CI, as well as wikis like this one regarding Doctrine: http://codeigniter.com/wiki/Using_Doctri...e_Igniter/.

If you want automatic mapping between objects from the database, then you are talking ORM.