How to Rebuild a Web Application Video into an Angular Application using Replay AI

TL;DR: Rebuild a web application from a video recording into a fully functional Angular application using Replay's behavior-driven reconstruction and Supabase integration.

Forget pixel-perfect screenshots. The future of code generation understands intent. We're moving beyond static images and into a world where video becomes the source of truth. I'm going to walk you through how to rebuild a web application from a simple video recording, turning it into a working Angular application using Replay.

The Problem with Traditional Code Generation#

Screenshot-to-code tools are a dime a dozen. But they all suffer from the same fundamental flaw: they only see the what, not the why. They generate code based on visual appearances, completely missing the user's journey and the application's underlying logic. This leads to brittle, incomplete code that requires significant manual intervention.

Behavior-Driven Reconstruction with Replay#

Replay changes the game by analyzing video recordings to understand user behavior and application flow. This "behavior-driven reconstruction" allows Replay to generate more accurate, complete, and maintainable code. We're talking multi-page applications, seamless Supabase integration, and intelligent style injection – all driven by the user's actions in the video.

Why Angular?#

Angular provides a robust framework for building complex web applications. Its component-based architecture, TypeScript support, and strong community make it an ideal choice for projects generated with Replay. The generated code will be clean, modular, and easy to maintain.

Rebuilding a Web Application: A Step-by-Step Guide#

Let's dive into the process of rebuilding a web application from video to Angular code using Replay. We'll assume you have a video recording of a user interacting with a simple web application – perhaps a basic to-do list or a simple e-commerce flow.

Step 1: Recording the Application Flow#

The first step is to record a clear and concise video of the application flow you want to rebuild. Make sure the video captures all the key interactions, including:

• •Page navigation
• •Form submissions
• •Button clicks
• •Data display

💡 Pro Tip: Speak clearly while recording to narrate what you are doing. This helps Replay better understand the user intent.

Step 2: Uploading and Processing the Video in Replay#

1. •Access Replay: Navigate to the Replay platform (https://replay.build).
2. •Upload Video: Upload the video recording of your web application flow.
3. •Configure Settings: Configure the output settings. Select "Angular" as the target framework. You can also specify a Supabase project if you want to automatically connect to your database.

📝 Note: The processing time will depend on the length and complexity of the video. Replay uses Gemini to analyze the video, identify UI elements, and understand user interactions.

Step 3: Reviewing the Generated Code#

Once the processing is complete, Replay will present you with the generated Angular code. This code will be structured into components, services, and modules, reflecting the application flow captured in the video.

Here's an example of a generated Angular component for a simple login form:

typescript
// src/app/components/login-form/login-form.component.ts
import { Component, OnInit } from '@angular/core';
import { AuthService } from '../../services/auth.service';

@Component({
  selector: 'app-login-form',
  templateUrl: './login-form.component.html',
  styleUrls: ['./login-form.component.css']
})
export class LoginFormComponent implements OnInit {
  username = '';
  password = '';
  errorMessage: string | null = null;

  constructor(private authService: AuthService) { }

  ngOnInit(): void {
  }

  async onSubmit() {
    try {
      await this.authService.login(this.username, this.password);
      // Redirect to dashboard or home page
    } catch (error: any) {
      this.errorMessage = error.message;
    }
  }
}

And the corresponding HTML template:

html
<!-- src/app/components/login-form/login-form.component.html -->
<div class="login-form">
  <h2>Login</h2>
  <div *ngIf="errorMessage" class="error-message">{{ errorMessage }}</div>
  <form (ngSubmit)="onSubmit()">
    <div class="form-group">
      <label for="username">Username:</label>
      <input type="text" id="username" name="username" [(ngModel)]="username" required>
    </div>
    <div class="form-group">
      <label for="password">Password:</label>
      <input type="password" id="password" name="password" [(ngModel)]="password" required>
    </div>
    <button type="submit">Login</button>
  </form>
</div>

Step 4: Integrating with Supabase (Optional)#

If you configured Replay to integrate with your Supabase project, the generated code will automatically include the necessary services and components for interacting with your database. This includes authentication, data fetching, and data manipulation.

⚠️ Warning: Ensure your Supabase credentials are secure and properly configured in your Angular application.

Replay can generate Supabase service files, like this:

typescript
// src/app/services/supabase.service.ts
import { Injectable } from '@angular/core';
import { createClient, SupabaseClient } from '@supabase/supabase-js';
import { environment } from 'src/environments/environment';

@Injectable({
  providedIn: 'root'
})
export class SupabaseService {
  private supabase: SupabaseClient;

  constructor() {
    this.supabase = createClient(environment.supabaseUrl, environment.supabaseKey);
  }

  getClient(): SupabaseClient {
    return this.supabase;
  }

  async getTodos() {
    const { data, error } = await this.supabase
      .from('todos')
      .select('*');

    if (error) {
      console.error('Error fetching todos:', error);
      return [];
    }

    return data;
  }

  async addTodo(task: string) {
    const { data, error } = await this.supabase
      .from('todos')
      .insert([{ task }]);

    if (error) {
      console.error('Error adding todo:', error);
    }

    return data;
  }
}

Step 5: Fine-Tuning and Customization#

While Replay generates a significant portion of the application code, some fine-tuning and customization may be required. This includes:

• •Adjusting Styles: Modify the CSS styles to match your desired design. Replay intelligently injects styles, but you may need to refine them.
• •Adding Custom Logic: Implement any custom business logic that wasn't explicitly captured in the video.
• •Connecting to APIs: Integrate with external APIs if your application requires it.

Step 6: Deploying Your Angular Application#

Once you're satisfied with the generated code, you can deploy your Angular application to your preferred hosting platform, such as Netlify, Vercel, or Firebase Hosting.

Benefits of Using Replay#

• •Faster Development: Significantly reduce development time by automating the code generation process.
• •Improved Accuracy: Generate more accurate and complete code compared to traditional screenshot-to-code tools.
• •Enhanced Maintainability: Create clean, modular, and maintainable Angular code.
• •Seamless Integration: Easily integrate with Supabase and other backend services.
• •Behavior-Driven: Capture user intent and application flow for a more realistic and functional application.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage. Paid plans are available for more extensive use and access to advanced features.

How is Replay different from v0.dev?#

While both tools aim to accelerate UI development, Replay uses video input and behavior-driven reconstruction, whereas v0.dev primarily uses text prompts and AI-generated designs. Replay focuses on replicating existing applications from video, while v0.dev focuses on creating new UIs from scratch.

What types of applications can I rebuild with Replay?#

Replay is suitable for rebuilding a wide range of web applications, from simple to-do lists to complex e-commerce platforms. The key is to capture a clear and concise video of the application flow.

What if the video quality is poor?#

While Replay can handle some level of video noise, a clear and well-lit video will always yield the best results. Ensure that the UI elements are clearly visible in the video.

Can I use Replay to rebuild mobile applications?#

Currently, Replay primarily focuses on web applications. Support for mobile application reconstruction may be added in the future.

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