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January 5, 20268 min readTechnical Deep Dive:

Technical Deep Dive: Using the Tailwind CLI Using Recorded UI for components

R
Replay Team
Developer Advocates

TL;DR: This article dives into using Replay's video-to-code engine to rapidly prototype Tailwind CSS components by recording UI interactions and generating functional code, eliminating tedious manual coding.

The future of UI development isn't writing code line by line. It's capturing user behavior and letting the machine reconstruct it. Screenshot-to-code tools are dead on arrival. They only understand visual appearances, not intent. We need tools that understand the why behind the UI.

That's where Replay comes in. We use "Behavior-Driven Reconstruction," treating video recordings as the source of truth to generate working, multi-page UI components. Forget static images; think dynamic user flows. And today, we're going to explore how to use Replay to generate Tailwind CSS components directly from recorded UI interactions.

The Problem: Tailwind CSS Component Development is Repetitive#

Tailwind CSS is fantastic for rapid styling. However, building even simple components often involves a tedious cycle:

  1. •Write HTML structure.
  2. •Add Tailwind classes.
  3. •Preview.
  4. •Adjust classes.
  5. •Repeat steps 3 and 4 ad nauseam.

This iterative process consumes valuable time that could be spent on higher-level logic and application architecture. And it's prone to errors. We need a way to bypass this repetitive churn.

The Solution: Replay + Tailwind CLI = Rapid Prototyping#

Replay analyzes video recordings of UI interactions, understanding the user's intent and generating functional code. Combined with the Tailwind CLI's JIT (Just-In-Time) mode, you can rapidly iterate on styles and see changes instantly. Here's the magic:

  1. •Record: Record yourself interacting with a UI design (e.g., Figma prototype, existing website). Show the behavior you want to capture.
  2. •Replay: Upload the recording to Replay.
  3. •Generate: Replay uses Gemini to generate the HTML and Tailwind CSS code.
  4. •Refine: Fine-tune the generated code, leveraging Tailwind's JIT mode for immediate feedback.

This approach shifts the focus from manual coding to guiding the machine with real-world examples.

Technical Deep Dive: Building a Button Component#

Let's walk through building a simple button component using Replay and the Tailwind CLI.

Step 1: Setup#

First, ensure you have Node.js and npm installed. Then, create a new project directory and initialize npm:

bash
mkdir tailwind-replay-demo
cd tailwind-replay-demo
npm init -y

Next, install Tailwind CSS, PostCSS, and Autoprefixer as development dependencies:

bash
npm install -D tailwindcss postcss autoprefixer

Create a

text
tailwind.config.js
file:

bash
npx tailwindcss init -p

This creates a basic Tailwind configuration file. We'll leave it with the default settings for this example.

Create a

text
src
directory and an
text
index.html
file inside it:

bash
mkdir src
touch src/index.html

Add the following Tailwind directives to your

text
src/index.html
file within the
text
<style>
tags:

html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Tailwind Replay Demo</title>
    <style>
        @tailwind base;
        @tailwind components;
        @tailwind utilities;
    </style>
</head>
<body>
    <h1>Button Demo</h1>
    <button class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded">
        Click Me
    </button>
</body>
</html>

Finally, start the Tailwind CLI in watch mode to process your CSS:

bash
npx tailwindcss -i ./src/index.html -o ./dist/output.css --watch

This command will watch your

text
src/index.html
file for changes and generate a
text
dist/output.css
file containing the compiled CSS. You'll need to link this CSS file in your HTML for the styles to apply.

Step 2: Recording the UI Interaction#

Now, use a screen recording tool (QuickTime on macOS, OBS Studio, etc.) to record yourself interacting with a button on a website or design prototype. The recording should clearly show:

  1. •The initial state of the button.
  2. •The hover state (if any).
  3. •The click/active state (if any).

Keep the recording short and focused on the button's behavior. The clearer the recording, the better the results from Replay.

Step 3: Generating Code with Replay#

Upload the recording to Replay. Replay will analyze the video and attempt to reconstruct the button's HTML and CSS. It will infer the different states (default, hover, active) based on the visual changes in the recording.

💡 Pro Tip: For best results, use a clean and consistent UI during the recording. Avoid distractions or sudden changes in the environment.

Step 4: Refining the Generated Code#

Replay will output code similar to this:

html
<button class="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded">
  Click Me
</button>

This code is a good starting point, but you'll likely need to refine it. For example, you might want to:

  • •Adjust the padding, font size, or border radius.
  • •Add or modify the hover/active states.
  • •Extract the button into a reusable component.

Tailwind's JIT mode makes this refinement process incredibly fast. Simply modify the Tailwind classes in your HTML, and the changes will be reflected in your browser instantly.

📝 Note: Replay's generated code may not be perfect on the first try. The key is to use it as a foundation and leverage your own knowledge of Tailwind CSS to fine-tune the component.

Step 5: Creating a Reusable Component#

Once you're happy with the button's appearance and behavior, you can extract it into a reusable component. This can be done in various ways, depending on your framework of choice (React, Vue, etc.).

For example, if you're using React, you could create a

text
Button.js
file:

jsx
// Button.js
import React from 'react';

const Button = ({ children, onClick }) => {
  return (
    <button
      className="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded"
      onClick={onClick}
    >
      {children}
    </button>
  );
};

export default Button;

And then use it in your application:

jsx
// App.js
import React from 'react';
import Button from './Button';

const App = () => {
  return (
    <div>
      <Button onClick={() => alert('Button clicked!')}>Click Me</Button>
    </div>
  );
};

export default App;

Replay vs. Traditional Methods: A Comparison#

Here's a comparison of Replay with traditional Tailwind CSS component development methods and screenshot-to-code tools:

FeatureManual CodingScreenshot-to-CodeReplay
InputCodeScreenshotVideo
Behavior Analysis❌❌✅
Multi-Page Support✅ (Manual)❌✅
Learning CurveHighMediumLow
AccuracyHighLowMedium (improving)
Time to PrototypeSlowMediumFast
Understanding Intent❌❌✅ (Behavior-Driven)
Supabase Integration❌❌✅
Style Injection❌❌✅
Product Flow Maps❌❌✅

As you can see, Replay offers a unique advantage by understanding user behavior from video recordings, enabling faster and more accurate prototyping.

Why Video Matters: Behavior-Driven Reconstruction#

The crucial difference between Replay and other code generation tools is our focus on behavior. Screenshots only capture a static image. They don't tell you how a user interacts with the UI, what happens on hover, or how the UI responds to clicks.

Video, on the other hand, provides a rich stream of information about user behavior. Replay analyzes this stream to infer the underlying logic and generate code that accurately reflects the intended functionality. This "Behavior-Driven Reconstruction" is the key to unlocking truly rapid and intelligent UI development.

⚠️ Warning: Replay works best with clear and consistent UI interactions. Avoid rapid mouse movements, sudden changes in the environment, or ambiguous gestures.

Benefits of Using Replay with Tailwind CLI#

  • •Rapid Prototyping: Generate Tailwind CSS components in seconds, not hours.
  • •Reduced Manual Coding: Minimize repetitive tasks and focus on higher-level logic.
  • •Improved Accuracy: Replay understands user behavior, leading to more accurate code generation.
  • •Enhanced Collaboration: Share video recordings and generated code with your team for faster feedback and iteration.
  • •Learning Tailwind: By seeing the generated code, you can learn more about Tailwind CSS classes and best practices.
  • •Supabase Integration: Seamlessly integrate generated components with your Supabase backend.
  • •Style Injection: Easily apply custom styles to generated components.
  • •Product Flow Maps: Visualize user flows and interactions within your application.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage. Paid plans are available for higher usage and access to advanced features. Check our pricing page for the most up-to-date information.

How is Replay different from v0.dev?#

v0.dev is a text-to-code tool. You describe the UI you want and it generates code. Replay is a video-to-code tool. You show Replay the UI and how you interact with it, and it generates code based on your behavior. Replay understands intent, not just appearance.

What kind of video formats does Replay support?#

Replay supports most common video formats, including MP4, MOV, and WebM.

Can I use Replay with other CSS frameworks besides Tailwind?#

While Replay is optimized for Tailwind CSS, it can also generate code for other CSS frameworks with some adjustments. We are actively working on expanding support for other frameworks.

Ready to try behavior-driven code generation? Get started with Replay - transform any video into working code in seconds.

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