Building Single Page Applications with Blazor and C#

Introduction to WebAssembly and Blazor

In this introduction we will look at how browsers are now capable of running .NET assemblies in the Browser using WebAssembly, .NET and Blazor. Getting hands on is the best way to learn. You will create your first Blazor project in Visual Studio, run the project to see it work, and finally inspect the different aspects of the project to get a “lay of the land” view for how Blazor applications are developed.

• Building Rich Web Experiences, Past, Present and Future
• Introducing Web Assembly
• Web Assembly and .NET
• Getting Started with Blazor – Easy!
• Understanding the difference between Blazor WASM and. Blazor Server
• Blazor Features Overview
• Generating your project with Visual Studio, dotnet CLI or Visual Studio Code
• Examining the generated solution and its projects
• LAB: Getting started with Blazor

Blazor Data Binding

Modern web applications use the Model-View-ViewModel approach which heavily relies on data binding. Blazor is no exception! We will look at the different ways to do data binding with Blazor.

• A Quick Look at Razor
• One Way Data Binding
• Event Handling and Data Binding
• Two Way Data Binding
• Reporting Changes with StateHasChanged
• LAB: Building a simple pizza ordering web site with Blazor

Blazor Forms and Validation

Most applications need users to enter some data. So how do we present this to the user, capture changes made and validate the data?

• Working with Forms in Blazor
• Adding validation to your forms
• Disabling the "Submit" button when validation detects errors
• Implementing custom validation in Blazor - Fluent Validation
• LAB: Adding a form to the PizzaPlace application

Blazor Components.

In modern web development we build applications by constructing them from components, which typically are again built from smaller components. A Blazor component is a self-contained chunk of user interface with a single responsibility. Blazor Components are classes built from razor and C# and are easier to understand, debug and maintain. And of course, you can re-use the same component in different pages.

• What is a Blazor Component?
• Building a Simple Blazor Component
• Component Parameters
• Conditional Rendering and ChildContent
• Separating the View and View-Model
• Component Data Binding
• Attribute Splatting
• Understanding EventCallback
• Referring to Components
• Styling Components
• LAB: Create components to improve the pizza ordering web site's maintainability

Understanding Blazor Component Lifecycle Hooks

Blazor Components are born, go through changes and get removed. Here we will look at places where you can intercept some of a component's life-cycle.

• Understanding Lifecycle Hooks
• Limiting unnecessary Rerendering of components with ShouldRender
• Using Virtualization to limit rendering
• Help Blazor with change detection using @key
• LAB: Limit unnecessary rerendering with ShouldRender

Reusing components with Component Libraries

You can easily distrubute your components as a component libary. This way your components can be used across several Blazor projects. We will also look at developing for both Blazor platforms with the ability to used advanced debugging features.

• Building a Component Library
• Consuming a Component Library
• Example: Using the QuickGrid Component
• LAB: Building for both Blazor WebAssembly and Blazor Server

Services and Dependency Injection.

Dependency Inversion is one of the basic principles of good Object-Oriented design. The big enabler is Dependency Injection. In this chapter we will discuss dependency inversion and injection and why it is a fundamental part of Blazer. We will illustrate this by building a Service that encapsulates where the data gets retrieved and stored.

• Understanding Dependency Inversion & Injection
• Some Inversion of Control Containers
• Blazor and Dependency Injection
• Building Blazor Services
• LAB: Create a service to talk to the data store

Data Storage and Microservices

In general client-side browser applications need to store some of their data. In some cases, such as game apps, the application can store its data in the browser itself, using browser local storage. But in most cases storage will happen on the server which has access to database engines such as SQL Server. In this chapter we will cover the basics of storing data using Entity Framework Core and exposing that data using REST and microservices built on top of ASP.NET Core. Of course Blazor can also work with REST services built on top of other runtimes.

• What is REST?
• Invoking Server Functionality with REST
• Building a Simple Microservice with ASP.NET Core
• What is Entity Framework Core?
• Generating the Database with Code First
• Testing your Microservice using Postman
• LAB: Storing the pizzas and orders in the database with EF Core

Communication with Microservices

So how do you talk to a REST service with Blazor? We will use the HttpClient class you probably already know from other .NET projects, but with a twist.

• Sending and receiving data
• Using the HttpClient Class and IHttpClientFactory interface
• The HttpClientJSONExtensions Methods
• Taking full control with HttpRequestMessage
• Retrieving Data From the Server
• Storing Changes
• LAB: Talk to the server

Single Page Applications and Routing.

Blazor is a .NET framework you use for building Single Page Applications, just like you can use popular JavaScript frameworks such as Angular, React and VueJs. But what is a Single Page Application (SPA)? We will look at using routing to jump between different sections of a SPA and sending data between different components.

• What is a Single Page Application?
• Using Layout Components
• Understanding Routing
• Setting the Route Template
• Redirecting to Other Pages
• Sharing State between Components
• Lazy Loading parts of your Blazor web site
• Handling location changing events
• LAB: Add a route to show a pizza's detail

JavaScript Interoperability

Sometimes there is just no escape from using JavaScript 😊. For example, Blazor itself uses JavaScript to update the browser's Document Object Model (DOM) from your Blazor components. You can too. In this chapter we will look at interoperability with JavaScript and, as an example, we will build a Blazor Component Library to display a geographic map.

• Why do we still need JavaScript in Blazor?
• Calling JavaScript from C#
• Calling .NET Methods from JavaScript
• Displaying a map with a JavaScript library
• LAB: Add a map to show the location of the resto and customer

Security

How can we add authentication to a Blazor application?

• Adding authentication to a Blazor Server application
• Adding authentication to a Blazor WASM application
• LAB: Protecting your Blazor application