ForPairs

A reactive state that updates based on when other values update, similar to computed, but only updating for specific key changes.

Type	Since	Scoped
State	0.4.3	Yes

Constructor

Computed(ReactiveValue : Value, CalculationFunction : (Use : (Value : Value) -> Value.Value, Index : any, Value: any) -> nil)

Properties

Value : any

The current value of the ForPairs state. Read-only.

Usage

ForPairs works just like computed behind the scenes, with the exception that only certain key changes will be triggered by index values in an array or dictionary value changes.

info

ForPairs is a better altnerative to Computed when re-computing similar arrays or dictionaries of data. For example, an inventory grid of items would benefit from this state, since Computed would force-computed every key, regardless of what changed specifically.

To construct, the first argument should be a value object that is always a table, with the second argument being a calculation similar to what you use in Computed. In addition to Use, this callback also passes Index and Value.

Rather than returning a final result calculation, you will only calculate on a per-value basis in the table.

Here is an example:

local MyValue = Value({1, 2, 3})

local TestState = ForPairs(MyValue, function(Use, Index, Value)
    return `{Index} = {Value * 2}`
end)

print(TestState.Value) -- Prints "1 = 2, 2 = 4, 3 = 6"

MyValue.Value = {4, 5, 6}

print(TestState.Value) -- Prints "1 = 8, 2 = 10, 3 = 12"