Re: Pattern to avoid circular reference?
On Dec 6, 10:01 pm, Karthik V <karthikveeram...@gmail.com> wrote:
I've been facing this situation often:
class NewFeature
{
TheClass *theClass;
NewFeature(TheClass *t) { theClass = t; }
void act() { // call methods on theClass }
}
class TheClass
{
NewFeature *feature; // More commonly, a list of NewFeature objects
AddFeature(NewFeature *f) { feature = f; // or append f to a list of
NewFeature objects }
}
In the above case, TheClass class contains pointers to NewFeature
objects, and each NewFeature object contains a pointer to the same
TheClass instance. This does seem to work most of the time but I'm not
comfortable with the idea of this circular reference.
Is there a standard design pattern to overcome this? The closest I saw
was visitor pattern. If I use that here, I'd do something like
class NewFeature
{
TheClass *theClass;
void accept(TheClass *t) { theClass = t; }
void act() { // call methods on theClass }
}
class TheClass
{
AddFeature(NewFeature *f) { f->accept(this); f->act(); }
}
But in this case, I'm losing the ability to keep track of the
NewFeature objects I have. Especially, if NewFeature.act() runs some
thread that calls TheClass methods later, I want TheClass to be able
to start / stop the thread when I want; so maintaining a list of those
pointers will be useful. If I do, I end up having my earlier code.
Please help!
There is nothing wrong with using your method. You have just keeping a
pointer to the object and not the actual object thus you have no
circular reference. All the pointer is in the most general sense is an
integer. Using the actual object would be bad though as this would be
like having a nested class structure and lead to looping in
compilation.
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