v1.1.0

This release fixes a minor reconciliation bug and introduces a new binding API, Roact.joinBindings.

Changes Since 1.0.0

• Fixed an issue where updating a host element with children to an element with nil children caused the old children to not be unmounted. (#210)
• Added Roact.joinBindings, which allows combining multiple bindings into a single binding that can be mapped. (#208)

Roact.joinBindings

The new joinBindings API can be used to combine multiple bindings and use them to create a new binding!

You can use this to implement flexible sizing without going through the reconciler, for example:

local function Flex()
	local aSize, setASize = Roact.createBinding(Vector2.new())
	local bSize, setBSize = Roact.createBinding(Vector2.new())

	return Roact.createElement("Frame", {
		Size = Roact.joinBindings({aSize, bSize}):map(function(sizes)
			local sum = Vector2.new()

			for _, size in ipairs(sizes) do
				sum = sum + size
			end

			return UDim2.new(0, sum.X,  0, sum.Y)
		end),
	}, {
		A = Roact.createElement("Frame", {
			Size = UDim2.new(1, 0, 0, 30),
			[Roact.Change.AbsoluteSize] = function(instance)
				setASize(instance.Size)
			end,
		}),
		B = Roact.createElement("Frame", {
			Size = UDim2.new(1, 0, 0, 30),
			Position = aSize:map(function(size)
				return UDim2.new(0, 0, 0, size.Y)
			end),
			[Roact.Change.AbsoluteSize] = function(instance)
				setBSize(instance.Size)
			end,
		}),
	})
end