What is Blazor?

Blazor is a modern web framework developed by Microsoft that allows developers to build interactive, client-side web applications using C# instead of JavaScript. The name “Blazor” is a combination of “Browser” and “Razor” (the templating engine used in ASP.NET Core). Blazor is part of the ASP.NET Core ecosystem and can run in the browser via WebAssembly or on the server, making it a versatile solution for modern web application development.

Blazor allows developers to leverage their existing C# and .NET skills to write client-side code directly, providing a seamless experience for full-stack developers. Blazor applications are highly interactive and can be used to create single-page applications (SPA) or progressive web apps (PWA), providing a similar experience to JavaScript-based frameworks like React or Angular.

Blazor uses WebAssembly to run .NET code in the browser, or it can run on the server using SignalR for real-time communication with the client-side.

Key Features of Blazor:

1. C# in the Browser: Developers can write client-side code using C# and Razor instead of JavaScript.
2. WebAssembly: Blazor WebAssembly allows .NET applications to run directly in the browser without needing a server round-trip.
3. Two Hosting Models: Blazor offers two modes—Blazor WebAssembly (client-side) and Blazor Server (server-side).
4. Reusability: Blazor enables the reusability of .NET libraries across both the client and server, ensuring consistency in logic.
5. Component-based: Blazor uses a component-based architecture, where UI elements and logic are encapsulated in reusable components.

What Are the Major Use Cases of Blazor?

Blazor is gaining popularity due to its flexibility, allowing developers to build various types of web applications. Below are the major use cases of Blazor:

1. Web Application Development:

• Use Case: Blazor is used for building full-fledged web applications where the frontend and backend can both be written in C#.
• Example: Developers can use Blazor to create admin dashboards, e-commerce websites, or enterprise applications without needing JavaScript.
• Why Blazor? The ability to use C# for both frontend and backend code simplifies development, particularly for teams already familiar with the .NET ecosystem.

2. Single-Page Applications (SPAs):

• Use Case: Blazor is ideal for building single-page applications (SPAs), which allow dynamic content loading without reloading the entire page.
• Example: A task management tool where users can add, delete, and edit tasks without refreshing the page.
• Why Blazor? It provides a responsive, interactive user experience by leveraging WebAssembly and client-side C# code execution.

3. Progressive Web Apps (PWAs):

• Use Case: Blazor allows developers to build progressive web apps that work offline and provide native-like experiences on the web.
• Example: Offline-capable apps like note-taking or calendar applications, which can work without an internet connection.
• Why Blazor? Blazor’s WebAssembly allows for native-like performance in the browser, making it a great choice for building PWAs.

4. Cross-Platform Development:

• Use Case: With Blazor, developers can build web applications that run across different platforms, such as Windows, macOS, and Linux, with minimal code changes.
• Example: A cross-platform data visualization app where the same application logic runs in the browser on various operating systems.
• Why Blazor? As WebAssembly runs in modern browsers across operating systems, Blazor applications are platform-independent.

5. Enterprise Applications:

• Use Case: Blazor is well-suited for enterprise applications that require high scalability, maintainability, and integration with other Microsoft technologies.
• Example: An enterprise-grade financial management tool that integrates with SQL Server, Azure, and other Microsoft services.
• Why Blazor? Blazor seamlessly integrates with ASP.NET Core, Entity Framework, and Azure, making it a great choice for enterprise solutions.

6. Real-time Applications (Blazor Server):

• Use Case: Blazor Server is useful for building real-time applications that require immediate updates, such as chat applications, collaborative tools, or live dashboards.
• Example: A real-time stock price monitoring dashboard that shows live updates based on the stock market.
• Why Blazor Server? Blazor Server uses SignalR to establish a persistent connection between the client and the server for real-time updates.

How Blazor Works Along with Architecture?

Blazor can operate using two main architectures: Blazor WebAssembly (client-side) and Blazor Server (server-side). Let’s explore how both architectures work and how Blazor functions within these contexts.

1. Blazor WebAssembly (Client-Side) Architecture:

• WebAssembly is a low-level assembly language that runs in modern browsers, enabling high-performance web applications. With Blazor WebAssembly, C# code is compiled into WebAssembly and executed directly in the browser.
• Process Flow:
  1. Compilation: C# code is compiled into WebAssembly (WASM) binary format.
  2. Execution: The WebAssembly runtime in the browser executes the C# code, running the Blazor app entirely on the client side.
  3. Interaction: UI updates and interactions are handled by Blazor’s component system, which communicates directly with the browser without the need for server communication (except for backend APIs).
• Advantages of Blazor WebAssembly:
  • Client-side execution: No need to rely on server requests for rendering UI updates.
  • Offline support: Applications can run offline once loaded into the browser.
  • Rich Interactivity: Provides rich, interactive experiences for web applications.

2. Blazor Server Architecture:

• Blazor Server works by maintaining a connection between the client and server using SignalR (a real-time communication library). In this architecture, the UI rendering occurs on the server, and only the UI updates are sent to the browser over a persistent connection.
• Process Flow:
  1. SignalR Connection: The client establishes a persistent SignalR connection with the server.
  2. UI Rendering: All UI components are executed on the server, and the results (UI updates) are sent to the browser over the SignalR connection.
  3. Interaction: When a user interacts with the UI (e.g., clicks a button or enters text), the events are sent back to the server to process and update the UI, which then updates the client-side.
• Advantages of Blazor Server:
  • Smaller Application Size: Only the UI updates are sent over the network, making it suitable for lower-bandwidth scenarios.
  • Real-time Communication: Best for applications that require real-time updates.
  • Centralized Logic: The application’s logic and state are stored on the server, simplifying management.

3. Common Components and Lifecycle:

• Blazor Components: In both WebAssembly and Server models, Blazor relies heavily on components—reusable, modular UI building blocks. Components have their own lifecycle, including:
  1. OnInitializedAsync(): Invoked when the component is initialized.
  2. OnParametersSetAsync(): Invoked when the parameters are set.
  3. OnAfterRenderAsync(): Invoked after the component is rendered.
• Component Reusability: Components can be reused across different pages and applications, allowing developers to build maintainable and scalable web applications.

What Are the Basic Workflow of Blazor?

The basic workflow in Blazor involves the following steps:

1. Set Up the Project:

• The first step in any Blazor project is to create a new Blazor application using Visual Studio or the .NET CLI.
• Example: Create a Blazor WebAssembly app using the .NET CLI:

dotnet new blazorwasm -o BlazorApp
cd BlazorApp
dotnet run

2. Design Components:

• Define your UI components. These components define the building blocks of your Blazor application, such as buttons, forms, data grids, etc.
• Each component is defined as a .razor file that includes HTML and C# code.
• Example: A simple Counter.razor component:

@page "/counter"

<h3>Counter</h3>

<p>Current count: @count</p>
<button class="btn btn-primary" @onclick="IncrementCount">Increment</button>

@code {
    private int count = 0;
    
    private void IncrementCount()
    {
        count++;
    }
}

3. Run and Test:

• After creating the necessary components, run the application to view the rendered components in a browser. The app will be served through a local development server.
• In Blazor WebAssembly, the app runs directly in the browser using WebAssembly, while in Blazor Server, it communicates with the server for rendering updates.

4. Debug and Deploy:

• Debug your application by using browser developer tools or the built-in debugging tools in Visual Studio. Once your application is ready, deploy it to a web server.
• Example Deployment: Deploy a Blazor app to Azure, AWS, or any web server that supports static files.

Step-by-Step Getting Started Guide for Blazor

To get started with Blazor, follow these steps:

Step 1: Install .NET SDK

• Make sure you have the .NET SDK installed on your machine. You can download it from the official Microsoft website.

Step 2: Create a Blazor Application

• Open your terminal or command prompt and run the following command to create a new Blazor application:

dotnet new blazorwasm -o BlazorApp
cd BlazorApp
dotnet run

Step 3: Create Components

• In the Pages folder, create a new .razor file for each component you want to build (e.g., Counter.razor).

Step 4: Run and Test the Application

• Once your components are ready, run the application locally to test it:

dotnet run

Step 5: Publish the Application

• Once you’re happy with the application, you can publish it to any web server or cloud service like Azure or AWS.

The post Guide to Blazor: Use Cases, Architecture, Workflow, and Getting Started appeared first on scmGalaxy.

📌 What is AspNetCore.Scalar?

AspNetCore.Scalar is a lightweight, extensible, and highly-focused library for ASP.NET Core applications that simplifies model binding, input validation, and data sanitization at the property level.

It introduces the concept of “Scalars”, which are strongly-typed wrappers around primitive data types like strings, integers, booleans, etc., adding value like automatic validation, normalization, and rich error handling — all without cluttering your core domain models.

In simple terms:

AspNetCore.Scalar helps you validate and normalize user input early, safely, and elegantly in your ASP.NET Core Web APIs and MVC apps.

Instead of spreading validation logic across your controllers, services, or view models, Scalar centralizes and automates it, keeping your application clean, secure, and easy to maintain.

📌 Major Use Cases of AspNetCore.Scalar

You can use AspNetCore.Scalar in a wide range of modern ASP.NET Core application scenarios:

• Web API Input Validation
  Validate user-provided API request fields (e.g., email addresses, usernames, phone numbers) early during model binding.
• Sanitize User Input
  Normalize or clean up raw data inputs like trimming whitespaces, enforcing case rules (lowercase, uppercase), or formatting numbers before they hit your application logic.
• Microservices Input Contracts
  Enforce strict input contracts between services by making sure incoming data follows expected formats and constraints.
• Security Hardening
  Prevent injection attacks and other input-related vulnerabilities by validating and sanitizing at the first point of entry.
• Domain-Driven Design (DDD)
  Encapsulate validation rules inside value objects without bloating the domain entities.
• Developer Productivity
  Reduce repetitive validation code and avoid cluttering controllers and DTOs with manual if-else checks.
• Error Reporting
  Provide clear and structured error messages on invalid user input automatically.

Overall, AspNetCore.Scalar is ideal for any project where input validation, data quality, and code maintainability are top priorities.

📌 How AspNetCore.Scalar Works (Architecture Overview)

AspNetCore.Scalar operates through a simple but powerful architectural flow:

🔹 Core Components:

• Scalar Types
  Custom classes that wrap a primitive type (like Email, PhoneNumber, Username).
• Scalar Model Binders
  Intercept incoming HTTP request data during the ASP.NET Core model binding pipeline and instantiate scalar types automatically.
• Scalar Validators
  Run predefined or custom validation rules (length checks, format validation, etc.) on the bound input data.
• Scalar Normalizers
  Optionally sanitize/transform input (e.g., trimming spaces, converting to lowercase).
• Integration with ModelState
  Scalar errors are pushed automatically into ModelState for seamless error reporting in APIs or MVC views.

🛠️ Internal Workflow:

1. Request data (query, body, route) arrives.
2. Model binding detects scalar types.
3. Scalars validate and normalize the data.
4. If validation passes, the scalar is injected into the controller action.
5. If validation fails, errors are added to ModelState, and appropriate HTTP 400 responses are generated.

This tight integration allows input processing before your application logic sees any data — keeping your business layer pure and safe.

📌 Basic Workflow of AspNetCore.Scalar

Here’s how a typical AspNetCore.Scalar interaction looks like:

1. Define a Scalar Class
   Create a strongly typed wrapper for a specific kind of input (like EmailAddress, Username).
2. Configure Scalar Bindings
   Register scalar types into the ASP.NET Core dependency injection system.
3. Bind Scalars in Controllers
   Use scalar types as parameters in API or MVC controller actions.
4. Validation and Normalization Happen Automatically
   Scalars validate incoming user input at the model-binding stage.
5. Handle Errors
   If input fails validation, ASP.NET Core automatically returns an error response, or you can customize the response.
6. Use Validated Data
   Valid scalar values are available in controller methods for further business processing.

📌 Step-by-Step Getting Started Guide for AspNetCore.Scalar

Here’s how you can easily get started:

1️⃣ Install AspNetCore.Scalar

You can install via NuGet:

dotnet add package AspNetCore.Scalar

Or in Visual Studio, search for AspNetCore.Scalar in the NuGet package manager.

2️⃣ Create Your First Scalar

using Scalar;

public class Email : ScalarOf<string>
{
    public Email(string value) : base(value) {}

    protected override void Validate()
    {
        if (string.IsNullOrWhiteSpace(Value))
            throw new ScalarValidationException("Email is required.");

        if (!Value.Contains("@"))
            throw new ScalarValidationException("Email must contain @ symbol.");
    }

    protected override string Normalize(string value)
    {
        return value.Trim().ToLower();
    }
}

3️⃣ Register Scalars in Startup

In your Program.cs or Startup.cs, register scalar model binding:

builder.Services.AddScalarModelBinder();

4️⃣ Use Scalars in Controller Actions

[ApiController]
[Route("[controller]")]
public class UsersController : ControllerBase
{
    [HttpPost]
    public IActionResult Register([FromBody] Email email)
    {
        // If this point is reached, email is already validated
        return Ok($"Registered user with email: {email.Value}");
    }
}

5️⃣ Customize Error Responses (Optional)

Customize model state error behavior:

builder.Services.Configure<ApiBehaviorOptions>(options =>
{
    options.InvalidModelStateResponseFactory = context =>
    {
        var errors = context.ModelState.Values
                       .SelectMany(x => x.Errors)
                       .Select(x => x.ErrorMessage);
        return new BadRequestObjectResult(new { Errors = errors });
    };
});

The post AspNetCore.Scalar Explained: Modern Input Validation and Binding for .NET Web Apps appeared first on scmGalaxy.