What is Blazor in .NET Core?

Overview of Blazor

           +-------------------------------+
           |                               |
           |   Blazor (Full Stack in C#)   |
           |                               |
           +-------------------------------+
                        |
    +-------------------+--------------------+
    |                                          |
+-------------------+               +-------------------+
|  Blazor WebAssembly  |              |   Blazor Server    |
|  (Runs in Browser)   |              |   (Runs on Server) |
+-------------------+               +-------------------+

Blazor is a UI framework in .NET Core for building interactive, client-side web applications using C# instead of JavaScript. It allows developers to create rich, modern web applications by leveraging Razor syntax and components while working entirely within the .NET ecosystem.

Blazor runs in two modes:

1. Blazor WebAssembly (WASM): Runs entirely on the client-side using WebAssembly, enabling .NET code to run in the browser.
2. Blazor Server: Runs on the server, with the UI updates sent to the client via SignalR (real-time communication over WebSockets).

Blazor is part of ASP.NET Core and integrates with the existing features of the .NET ecosystem, such as dependency injection, routing, and component-based development.

The Idea Behind Blazor

Full-Stack with C#

+----------------------------------+
| Full Stack Development in C#     |
+----------------------------------+
|  Client-side UI     |  Server-side Logic   |
| (Blazor Components) |  (.NET APIs, DB)     |
+----------------------------------+

Blazor aims to provide full-stack web development using .NET. Traditionally, web development involves using JavaScript for client-side interactivity and C# or other languages for server-side logic. With Blazor, developers can build both the client-side and server-side parts of a web application using C#.

The core idea is to give .NET developers a way to use their existing C# knowledge to create rich, client-side web applications without needing to learn JavaScript frameworks like React or Angular.

Key Features of Blazor

Component-Based Architecture

  +----------------------------------+
  |      Parent Component (App)      |
  +----------------------------------+
               |
    +------------------+  +------------------+
    |   Child Component |  |  Child Component |
    +------------------+  +------------------+

• C# and .NET for full-stack development: Allows you to share code and libraries between client and server.
• Component-based architecture: Web applications are built using reusable UI components.
• Single Page Application (SPA): Blazor supports SPA development for building modern, dynamic, and fast web applications.
• WebAssembly support: Runs C# code directly in the browser via WebAssembly, without plugins.
• Integration with .NET ecosystem: Can use existing .NET libraries, tools, and features like dependency injection, LINQ, and Entity Framework.
• Razor Components: Uses the Razor syntax to create interactive components for the UI.
• Interoperability with JavaScript: If needed, Blazor can interoperate with JavaScript for complex tasks.

Blazor Hosting Models

1. Blazor WebAssembly (Client-Side):

   WebAssembly Client-Side Flow

   +----------------+        +--------------+       +--------------+
   |  Browser       | <----> |  Blazor App  |       |  WebAssembly |
   +----------------+        +--------------+       +--------------+
   • Runs entirely in the browser using WebAssembly.
   • The application is downloaded to the client, including the .NET runtime and DLLs, and runs directly within the browser.
   • No server round trips for rendering UI; everything happens client-side.

2. Blazor Server (Server-Side):

   Server-Side Communication

   +--------------+     WebSocket    +--------------+
   |    Client    | <--------------> |   Blazor App  |
   +--------------+    (SignalR)     +--------------+
   • The application runs on the server, with the UI updates communicated to the client via SignalR (real-time communication).
   • The server handles most of the computation, while the browser merely reflects the UI changes.
   • Only minimal data is sent back and forth (typically, events like button clicks or UI updates).

Benefits of Blazor

Benefits of Blazor

  +--------------------------------+
  |         Benefits of Blazor     |
  +--------------------------------+
  |  1. Full .NET Stack            |
  |  2. Component-Based UI         |
  |  3. WebAssembly Performance    |
  |  4. Server-Side or Client-Side |
  +--------------------------------+

1. Full .NET Stack for Web Development:

   • Blazor allows developers to write both the client-side and server-side of web applications in C#, sharing code and libraries across both.
   • Developers can use their existing .NET skills, tools, and libraries.

2. Avoid JavaScript for Complex UI Logic:

   • No need to use JavaScript for building interactive web UIs. This allows developers who prefer C# to avoid the complexities of JavaScript frameworks.

3. Component-Based Development:

   • Similar to modern frameworks like React and Angular, Blazor uses a component-based architecture. Each UI element is built as a reusable component, promoting modularity and easier maintenance.

4. WebAssembly Performance:

   • Blazor WebAssembly runs .NET code directly in the browser at near-native speed. It leverages WebAssembly, a binary instruction format that runs in modern browsers.

5. Great Developer Experience:

   • Developers can use familiar .NET tools like Visual Studio, NuGet, and the powerful C# language to build web applications.
   • Integration with .NET tooling (e.g., debugging, testing, code sharing) makes development smoother.

6. No Plugins or Native Dependencies:

   • Blazor WebAssembly runs entirely within the browser using WebAssembly, so no additional plugins (like Silverlight or Flash) are needed.
   • This also makes deployment easier, as applications run across all modern browsers.

7. Server-Side Rendering:

   • With Blazor Server, applications can run on the server, and only UI events and updates are transmitted to the client. This approach reduces the initial payload and increases app performance on low-powered devices.

8. Seamless JavaScript Interop:

   • While Blazor enables building apps without JavaScript, developers can still interoperate with JavaScript when needed, allowing for incremental adoption of Blazor in existing JavaScript-heavy apps.

9. Cross-Platform:

   • Since Blazor is built on top of ASP.NET Core, it runs cross-platform (Windows, macOS, Linux). Applications can be hosted on different environments.

Blazor Use Cases

• Single Page Applications (SPAs): Blazor can be used to create dynamic, modern SPAs without relying on JavaScript frameworks like Angular or React.
• Line-of-Business (LoB) Applications: Businesses looking to streamline web development and reuse existing .NET infrastructure can leverage Blazor.
• Progressive Web Applications (PWAs): Blazor can be used to build PWAs, which offer offline capabilities and app-like behavior.
• Internal Tools: Companies can build internal web-based tools using Blazor to keep everything in .NET.

Differences Between Blazor and Traditional JavaScript Frameworks

+-----------------------+-----------------------+-----------------------+
|   Feature             |      Blazor            |   JavaScript Frameworks|
+-----------------------+-----------------------+-----------------------+
| Primary Language      |       C#               |      JavaScript        |
| Hosting Models        |  WebAssembly, Server   | Client-side            |
| Tooling               |   .NET Tools (VS, CLI) | npm, webpack, etc.     |
+-----------------------+-----------------------+-----------------------+

Conclusion

Blazor Ecosystem Overview

+------------------------------------------+
|               Blazor                     |
+------------------------------------------+
|  Full-Stack in C# |  Reusable Components |
|  WebAssembly      |  .NET Ecosystem      |
|  Server-side UI   |  Client-side UI      |
+------------------------------------------+

Blazor represents a major shift in how web applications can be built in the .NET ecosystem, allowing developers to leverage the power of C# and the broader .NET platform for full-stack web development. With its component-based architecture, cross-platform support, and integration with WebAssembly, Blazor enables a seamless experience for .NET developers to build modern, interactive web applications without needing JavaScript frameworks.