Learning how to use roact for roblox ui is a bit like switching from a manual typewriter to a high-end laptop; it feels weird at first, and you might miss the "tactile" feel of dragging frames around in Roblox Studio, but once you get it, you'll never want to go back. If you've ever found yourself drowning in a sea of Instance.new("Frame") calls or struggling to keep your UI updated when a player's stats change, Roact is going to be your new best friend. It's a declarative library for Roblox that's heavily inspired by React, and it changes the way we think about building interfaces.
Instead of telling Roblox how to change the UI (step-by-step instructions), you just describe what the UI should look like at any given time. It's a subtle shift in logic, but it makes your code way cleaner and much easier to debug.
Why Even Bother with Roact?
Look, I get it. The standard "drag-and-drop" method in Roblox Studio is easy for small projects. You make a ScreenGui, throw in some frames, add a local script, and you're done. But as soon as your game grows—maybe you're building a complex inventory system or a detailed HUD—managing those instances becomes a nightmare. You end up with "spaghetti code" where one script is trying to hide a frame while another is trying to change its color, and suddenly everything is flickering or breaking.
Roact solves this by making the UI a direct reflection of your data. If your data changes, Roact automatically updates the UI to match. You don't have to manually find the TextLabel and change its text; you just tell Roact, "The text should be whatever is in this variable," and it handles the rest.
Getting Started: The Setup
Before we dive into the code, you need to actually get Roact into your project. Most professional developers use Rojo to sync code from VS Code into Roblox, which is the "proper" way to use Roact. However, if you're just starting out, you can simply grab the Roact model from the Creator Store or GitHub and drop it into ReplicatedStorage.
Once you've got the Roact module sitting there, you're ready to start scripting. You'll usually want a single LocalScript (often called a "Main" or "Mount" script) that handles the initial setup.
Your First Component
In Roact, everything is a component. A component is just a piece of UI—like a button, a health bar, or an entire menu. Here's a super basic example of how to create a simple label:
```lua local Roact = require(game.ReplicatedStorage.Roact)
local MyLabel = Roact.createElement("TextLabel", { Size = UDim2.new(0, 200, 0, 50), Position = UDim2.new(0.5, -100, 0.5, -25), Text = "Hello, Roact!", BackgroundColor3 = Color3.fromRGB(255, 255, 255) })
local handle = Roact.mount(MyLabel, game.Players.LocalPlayer.PlayerGui, "HelloWorldUI") ```
In this snippet, Roact.createElement is the star of the show. It takes three arguments: the type of instance (a TextLabel), a table of properties (Size, Text, etc.), and any children (which we left out here). Then, Roact.mount actually puts it into the game.
Understanding Props and State
This is where things get interesting. If you want to know how to use roact for roblox ui effectively, you have to master Props and State.
Props (short for properties) are things you pass into a component from the outside. Think of them like arguments in a function. If you have a "BlueButton" component, you might pass in the text you want that button to display as a prop.
State, on the other hand, is internal. It's the component's memory. If you have a button that tracks how many times it's been clicked, that "click count" is state. When the state changes, Roact "re-renders" the component automatically.
Creating a Functional Component
While the createElement method works, most people use "Stateful Components" or "Functional Components." Here's a quick look at a button that changes color when you click it:
```lua local Counter = Roact.Component:extend("Counter")
function Counter:init() -- Setting the initial state self:setState({ count = 0 }) end
function Counter:render() return Roact.createElement("TextButton", { Size = UDim2.new(0, 200, 0, 50), Text = "Clicks: " .. self.state.count, [Roact.Event.MouseButton1Click] = function() self:setState({ count = self.state.count + 1 }) end }) end ```
See how we didn't have to manually find the button and update its text? We just updated the state, and Roact saw that change and decided, "Hey, I need to redraw this button because the count changed."
Deeply Nested UI (Children)
In a real game, you're not just making one label. You're making frames inside frames inside scrolling frames. Roact handles this by letting you pass a third argument to createElement: a table of children.
lua local MyMenu = Roact.createElement("Frame", { Size = UDim2.new(0, 400, 0, 300), }, { Header = Roact.createElement("TextLabel", { Text = "Main Menu", Size = UDim2.new(1, 0, 0, 50), }), CloseButton = Roact.createElement("TextButton", { Text = "X", Position = UDim2.new(1, -50, 0, 0), Size = UDim2.new(0, 50, 0, 50), }) })
By nesting elements like this, your code structure actually starts to look like the UI hierarchy in the Explorer window. It's very visual, even though it's just text.
The "Thinking in Roact" Mindset
The hardest part about figuring out how to use roact for roblox ui isn't the syntax—it's the mental shift. You have to stop thinking about events and start thinking about data.
Don't think: "When the player dies, find the screen and make it red." Think: "The UI should be red whenever the player is dead."
It sounds like the same thing, but in code, it's the difference between a mess of listeners and a clean, predictable system. If you base your UI on a "Store" (like Rodux, which is the Roblox version of Redux), you can have one central place where all your game data lives, and your UI just listens to that data.
Tips for the Road
- Don't mount everything at once: Only mount your main App component. Everything else should be a child of that.
- Keep components small: Don't write a 500-line script for your whole HUD. Break it down! Make a
HealthBarcomponent, aStaminaBarcomponent, and anInventorySlotcomponent. It makes things way easier to fix later. - Use Roact-align or similar tools: If you're using VS Code, look into developer tools that help you visualize your Roact tree.
- Watch out for performance: Roact is fast, but if you're re-rendering a massive list of 1,000 items every single frame, you're going to feel it. Use keys (a special property) to help Roact track which items changed and which stayed the same.
Is Roact Still the Best Choice?
Now, a quick "pro tip." While Roact is amazing, Roblox actually officially released their own version of React recently (often called React-lua). It's very, very similar to Roact, but it's more aligned with the modern JavaScript React ecosystem (using things like Hooks).
If you're just learning how to use roact for roblox ui today, don't worry—the skills are almost 100% transferable. Roact was the pioneer, and it's still used in countless top-tier games. Whether you use the original Roact or the newer Roblox React, the declarative philosophy is the same.
Final Thoughts
Making the jump to Roact feels like a lot of work at first. You'll probably spend an hour just trying to get a frame to show up correctly. But once it clicks, you'll find that you can build interfaces ten times faster than you used to. No more hunting through the Explorer for a misplaced UICorner, and no more writing wait() loops to check if a value has changed.
The Roblox UI landscape is evolving, and declarative libraries are at the center of it. Take the time to practice, build a few small components, and before you know it, you'll be building complex, reactive UIs that look and feel like professional software. Happy coding!