Building TodoApp with Blazor WebAssembly: Modern .NET Web Development

The Challenge: Modern Web Development with .NET

The TodoApp project was born from a desire to explore modern web development with Microsoft’s .NET ecosystem. “How can we create rich, interactive web applications using C# instead of JavaScript?” This wasn’t just about building another todo app - it was about leveraging the power of .NET for full-stack web development.

The project combines Blazor WebAssembly’s client-side capabilities with .NET’s robust development experience to create a modern, responsive web application.

📝 What I Built

The TodoApp is a comprehensive web application that provides:

Single Page Application: Fast, responsive user experience with no page reloads
Real-time Updates: Instant UI updates without server roundtrips
Data Persistence: Local storage and state management
Responsive Design: Works seamlessly across all devices
Component Architecture: Reusable UI components with Razor syntax
Modern UI: Clean, intuitive interface with smooth animations

🛠️ The Technical Stack

Frontend: Blazor WebAssembly

I chose Blazor WebAssembly for its ability to run C# in the browser:

// Example of a Blazor component
@page "/todo"
@using TodoApp.Data

<h3>Todo List</h3>

<div class="form-group">
    <input @bind="newTodo" @bind:event="oninput" @onkeypress="@(async (e) => { if (e.Key == "Enter") { await AddTodo(); } })" 
           placeholder="What needs to be done?" class="form-control" />
    <button @onclick="AddTodo" class="btn btn-primary">Add Todo</button>
</div>

<ul class="list-group">
    @foreach (var todo in todos)
    {
        <li class="list-group-item d-flex justify-content-between align-items-center">
            <span class="@(todo.IsComplete ? "text-muted text-decoration-line-through" : "")">
                @todo.Title
            </span>
            <button @onclick="() => RemoveTodo(todo)" class="btn btn-sm btn-danger">Delete</button>
        </li>
    }
</ul>

@code {
    private List<TodoItem> todos = new();
    private string newTodo = "";

    private async Task AddTodo()
    {
        if (!string.IsNullOrWhiteSpace(newTodo))
        {
            todos.Add(new TodoItem { Title = newTodo });
            newTodo = "";
            StateHasChanged();
        }
    }

    private void RemoveTodo(TodoItem todo)
    {
        todos.Remove(todo);
        StateHasChanged();
    }
}

Data Models: C# Classes

Clean, type-safe data models:

// Example of a data model
public class TodoItem
{
    public int Id { get; set; }
    public string Title { get; set; } = "";
    public bool IsComplete { get; set; }
    public DateTime CreatedDate { get; set; } = DateTime.Now;
}

Component Architecture: Razor Components

Reusable UI components with proper separation of concerns:

// Example of a reusable component
@code {
    [Parameter]
    public string Title { get; set; } = "";

    [Parameter]
    public EventCallback<string> OnTitleChanged { get; set; }

    [Parameter]
    public bool IsComplete { get; set; }

    [Parameter]
    public EventCallback<bool> OnCompleteChanged { get; set; }
}

🔧 The Biggest Challenges

1. State Management

Managing application state in a Blazor WebAssembly app was challenging. I had to:

Implement proper component lifecycle management
Handle state updates and UI re-rendering
Manage local storage for data persistence
Ensure proper state synchronization

2. Component Communication

Building a component-based architecture required:

Understanding parameter passing between components
Implementing event callbacks for parent-child communication
Managing component lifecycle events
Creating reusable component libraries

3. Performance Optimization

Ensuring the app runs smoothly in the browser meant:

Optimizing component rendering
Implementing virtual scrolling for large lists
Managing memory usage
Reducing bundle size

4. Browser Compatibility

Making the app work across different browsers involved:

Testing WebAssembly support
Handling browser-specific behaviors
Ensuring consistent rendering
Managing polyfills and fallbacks

🎯 What I Learned

Blazor WebAssembly

Component Lifecycle: Understanding component initialization and disposal
State Management: Managing application state effectively
Event Handling: Implementing user interactions and callbacks
Data Binding: Using one-way and two-way data binding
Routing: Implementing client-side routing with Blazor

.NET Web Development

Razor Syntax: Writing dynamic HTML with C#
Dependency Injection: Using DI container in Blazor
Configuration Management: Managing app settings
Error Handling: Implementing proper error boundaries
Logging: Adding comprehensive logging

Modern Web Development

Single Page Applications: Building SPAs with .NET
Component Architecture: Creating reusable UI components
Responsive Design: Making apps work on all devices
Performance Optimization: Optimizing for web performance
Progressive Enhancement: Building accessible web apps

Development Experience

Hot Reload: Using Blazor’s hot reload capabilities
Debugging: Debugging C# code in the browser
Testing: Writing unit tests for Blazor components
Deployment: Deploying Blazor WebAssembly apps
Tooling: Using Visual Studio and VS Code effectively

🚀 The Impact

The TodoApp demonstrates:

Modern .NET Development: Showcasing .NET’s web capabilities
Component Reusability: Creating maintainable UI components
Performance: Fast, responsive web applications
Developer Experience: Excellent tooling and debugging
Cross-Platform: Running C# code in any modern browser

🔮 Future Enhancements

Looking ahead, I plan to:

Add Backend Integration: Connect to ASP.NET Core Web API
Implement Authentication: Add user authentication and authorization
Add Real-time Features: Implement SignalR for live updates
Add Offline Support: Implement PWA features
Add Testing: Comprehensive unit and integration tests

💡 Key Takeaways

This project taught me that .NET is a powerful platform for modern web development. Blazor WebAssembly brings the full power of C# to the browser, enabling developers to build rich, interactive web applications with familiar tools and languages.

The most rewarding part was seeing how C# code could run directly in the browser, providing a seamless development experience from backend to frontend. The component-based architecture and strong typing made the codebase more maintainable and less error-prone.

The TodoApp stands as a testament to .NET’s evolution into a full-stack development platform. It’s a reminder that modern web development doesn’t have to mean abandoning the benefits of strongly-typed languages and excellent tooling.

This project continues to evolve as I explore more advanced Blazor features and .NET web development capabilities. The journey of building modern web applications with .NET is ongoing, and each iteration brings new insights and improvements.

The Challenge: Modern Web Development with .NET#

📝 What I Built#

🛠️ The Technical Stack#

Frontend: Blazor WebAssembly#

Data Models: C# Classes#

Component Architecture: Razor Components#

🔧 The Biggest Challenges#

1. State Management#

2. Component Communication#

3. Performance Optimization#

4. Browser Compatibility#

🎯 What I Learned#

Blazor WebAssembly#

.NET Web Development#

Modern Web Development#

Development Experience#

🚀 The Impact#

🔮 Future Enhancements#

💡 Key Takeaways#