Convert to Single-Page Application (SPA) with MSAL Authentication

[Copilot]

Overview

This PR converts the BuildEvents application from a server-side rendered (SSR) web application to a Single-Page Application (SPA) with MSAL (Microsoft Authentication Library) for Azure AD authentication.

Problem Statement

The application architecture needed clarification regarding whether it should be a Single-Page Application or a Web Application, and which authentication pattern to use:

• Single-Page Application (SPA): Runs entirely in browser, uses MSAL for client-side authentication, is a public client unable to store secrets
• Web Application: Runs code on server, maintains sessions, is a confidential client that can store secrets

This PR implements the SPA architecture with MSAL React, following Microsoft's recommended pattern for browser-based applications.

Changes Made

1. SPA Mode Configuration

Changed react-router.config.ts to enable SPA mode:

export default {
  ssr: false,  // Enables SPA mode
} satisfies Config;

2. MSAL Authentication Integration

• Added dependencies: @azure/msal-react and @azure/msal-browser
• Created store/authConfig.ts: MSAL configuration with environment variable support
• Updated store/useuser.tsx: Now uses useMsal() hook instead of server-side /.auth/me endpoint
• Created app/entry.client.tsx: Custom entry point that wraps the app with MsalProvider

3. Client-Side Data Fetching

Converted all server-side loaders to client-side data fetching using useEffect:

• app/routes/home.tsx - Design configuration loaded on client
• app/routes/app.tsx - Design configuration loaded on client
• app/favicon.tsx - Converted to static component

4. Documentation

• web/docs/AUTHENTICATION.md: Complete Azure AD setup guide
• web/docs/SPA_CONVERSION_SUMMARY.md: Technical implementation details
• web/.env.example: Environment variable template
• Updated web/README.md: Describes the SPA architecture

Authentication Architecture

Feature	Implementation
Framework	React with React Router (SPA mode)
Auth Library	MSAL React
Client Type	Public Client
Token Management	ID tokens for sign-in, Access tokens for APIs
Local Development	Uses default user (no Azure AD required)

Local Development

For localhost development, the application uses a default user automatically:

const defaultUser = {
  key: "seth-juarez",
  name: "Seth Juarez",
  email: "[email protected]",
  avatar: "/images/people/seth-juarez.jpg"
};

This allows immediate development without requiring Azure AD configuration.

Production Setup

To enable Azure AD authentication in production:

1. Register app in Azure AD as Single-page application (SPA)
2. Configure environment variables:

   VITE_AZURE_CLIENT_ID=your-client-id
   VITE_AZURE_AUTHORITY=https://login.microsoftonline.com/tenant-id
   VITE_AZURE_REDIRECT_URI=https://your-domain.com

3. Deploy static files from build/client directory

Screenshots

Home Page (SPA Mode):

App Page (showing default user for localhost):

Benefits

• ✅ Simpler Deployment: Static files only, no Node.js server required
• ✅ CDN-Friendly: Can be deployed to any CDN for global distribution
• ✅ Industry Standard: Follows Microsoft's recommended SPA authentication pattern
• ✅ Better Caching: Static assets can be aggressively cached
• ✅ Client-Side Routing: Instant page transitions

Testing

• ✅ TypeScript compilation successful
• ✅ Build generates proper SPA output with isSpaMode: true
• ✅ Application loads correctly in browser
• ✅ Default user displayed for localhost
• ✅ All routes functional

Documentation

• 📚 Authentication Setup Guide
• 📚 SPA Conversion Summary
• 📚 Environment Configuration

References

• MSAL React Documentation
• Azure AD SPA Quickstart
• React Router SPA Mode

Original prompt

Is this a single-page application or a web application? Single-page application (SPA)
A single-page application runs entirely in the browser and fetches page data (HTML, CSS, and JavaScript) dynamically or at application load time. It can call web APIs to interact with back-end data sources.

Because a SPA's code runs entirely in the browser, it's considered a public client that's unable to store secrets securely.

Language / framework Project on
GitHub Package Getting
started Sign in users Access web APIs
React MSAL React2 msal-react Quickstart Library can request ID tokens for user sign-in. Library can request access tokens for protected web APIs.
JavaScript MSAL.js2 msal-browser Quickstart Library can request ID tokens for user sign-in. Library can request access tokens for protected web APIs.
Angular MSAL Angular2 msal-angular Quickstart Library can request ID tokens for user sign-in. Library can request access tokens for protected web APIs.
Web application
A web application runs code on a server that generates and sends HTML, CSS, and JavaScript to a user's web browser to be rendered. The user's identity is maintained as a session between the user's browser (the front end) and the web server (the back end).

Because a web application's code runs on the web server, it's considered a confidential client that can store secrets securely.

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