Access Parent Instance Variables from a Nested Class

[JoeSchmoe]

Hello,

Is there a recommended way for a method in a nested class to access the properties of the parent object?

For example:

Code: Select all

class ClassName 
{
    InstanceVar := Expression
    class NestedClass
    {
    	Method()
    	{
        	; How do I access InstanceVar from here?
    	}
     }
}

[nnnik]

@JoeSchmoe you need a reference towards the instance of ClassName in the NestedClass.
But unless we know how your classes relate to one another it's difficult to say.

[jeeswg]

Some ideas. Based on the example by Helgef here:
object classes: redefine __Set() temporarily / general queries - AutoHotkey Community
https://autohotkey.com/boards/viewtopic ... 47#p193947

Code: Select all

q::
obj := ClassName.NestedClass.Method()

obj := new ClassName.NestedClass
obj.Method()

ClassName.__Init.Call(o:=[])
MsgBox, % o.InstanceVar
return

class ClassName 
{
    InstanceVar := "Expression"
    class NestedClass
    {
    	Method()
    	{
        	; How do I access InstanceVar from here?
		ClassName.__Init.Call(o:=[])
		MsgBox, % o.InstanceVar " " A_ThisFunc

		vClass := StrSplit(A_ThisFunc, ".")[1]
		%vClass%.__Init.Call(o:=[])
		MsgBox, % o.InstanceVar " " A_ThisFunc
    	}
     }
}

[nnnik]

I would advise against this due to a mass of reasons that I'm not going to mention here.

[Helgef]

The important point is that instantiating either of the two classes, doesn't imply an instance of the other. Hence, as hinted by nnnik, if the child needs a parent, the child needs to create it (the parent doesn't need to know ), or the parent needs to create a child and tell it (and then the parent can forget it ever happened ).

Cheers.

[JoeSchmoe]

The important point is that instantiating either of the two classes, doesn't imply an instance of the other. Hence, as hinted by nnnik, if the child needs a parent, the child needs to create it (the parent doesn't need to know ), or the parent needs to create a child and tell it (and then the parent can forget it ever happened ).

Cheers.

Thanks, everyone, and especially Helgef for that super clear summary. It all makes perfect sense now.