You don't seem to have worked with behaviors much. Try to use the containable, tree or other core or plugin behaviors, then you will soon figure out the basics.
First of all, behaviors are attached to models (and since 2.3: loaded), not the other way around. A model then gets "richer" in functionality.
Either statically be using public $actsAs
or dynamically using
$this->Behaviors->attach('Something'); // since 2.3: load() instead of attach()
It can directly access the behavior methods. Lets say we have a method foo() in your behavior. You can then call it from your model as
$this->foo($foo, $bar);
Or from your controller as
$this->Document->Behaviors->attach('Something')
$this->Document->foo($foo, $bar);
Awesome, right? The behavior method usually has this declaration:
public function foo(Model $Model, $foo, $bar) {
$alias = $Model->alias;
// do sth
}
As you can see, you always pass the model into it implicitly (as first argument automatically passed). You can access all its attributes.
And do not touch the constructor of the model. no need to do that.
If you really need to pass an object in at runtime, why does your approach not work?
public function setObject(MyClass $obj) {
$this->Obj = $obj;
}
Now you can internally use the object from your behavior methods
public function doSth(Model $Model) {
$this->Obj->xyz();
}
Also this might not be the most elegant approach.