Laravel 4 Present Model - php

Question

In Laravel 4, I have a model linking to a database table. Let's call it Model.
Say that this model has a database column called Property A and Property B.
When I make get request call to my model, i.e. Model::all() or Model::find($id), I don't want to return Property A or Property B, but some kind of function of the two, which appears to the front-end as some kind of read-only field, i.e. Property C.
Do I need to use a presenter library here, or is there a way by overriding model functions within Laravel 4?
The key for me here is that the property shows up when I call Model::all()
EDIT:
From my understanding this should return an attribute with the name foo constantly with the value "foo":
Model
class DiscountLink extends Eloquent {
protected $table = 'discountLinks';
protected $hidden = array('tag');
protected $fillable = array('name', 'currency', 'language', 'price', 'instalments', 'expires', 'active', 'foo');
public function getFooAttribute()
{
return "foo";
}
}
Controller
class DiscountLinkController extends \BaseController {
public function index()
{
return DiscountLink::all();
}
}

Answer 1

Use an accessor in your Model. To concatenate A and B, for instance:
public function getPropertyCAttribute()
{
return $this->attributes['property_a'] . ' ' . $this->attributes['property_b'];
}
And then you can access Model::find($id)->propertyC.
If you want the attribute to be automatically included in your model's results array (e.g. if you're sending the results of Model::all() or Model::get() as JSON, for example), add an $appends declaration to the top of your model:
protected $appends = array('PropertyC');
If the function is something that can be done in the database (like concatenation, sum, etc.), you could also add a DB::raw command to your query, like:
Model::select(*, DB::raw('CONCAT(PropertyA, " ", PropertyA) AS PropertyC'))->...