Friends & Mutual Trust¶
In traditional OOP, your choices for member visibility are often binary: either everyone can see it (public), only family can see it (protected), or only you can see it (pri`vate).
Ignition introduces Friends, allowing you to grant specific external objects or functions access to your internal state without compromising your class hierarchy.
The friend Helper¶
The friend function creates a one-way trust relationship. If Object A friends Object B, then B can see A's secrets, but A cannot see B's.
When you friend another object, you are trusting every method and the constructor of that object.
local player = new(PlayerClass)()
local pet = new(PetClass)()
-- Pet can now access player's private properties
friend(player, pet)
This is the least privilege approach. You can trust a specific method by its name. This allows the guest to access your private data only while that specific method is running.
-- Only trust the 'Sync' method of the DataManager
friend(MyObject, DataManager, "Sync")
You can also friend raw Luau functions or tables containing functions (like utility libraries).
friend(MyObject, function()
-- This specific closure can now touch MyObject's private fields
end)
mutual Trust¶
If you want two objects to have full access to each other's internals (a "partnership" relationship), use mutual. This is equivalent to calling friend twice in both directions.
local PartA = new(PhysicsObject)()
local PartB = new(PhysicsObject)()
-- Both objects can now see each other's private physics state
mutual(PartA, PartB)