10 Blazor Best Practices

Blazor is an open-source web framework that allows developers to create interactive web apps using C# and HTML. It’s a great way to create rich and dynamic web applications without having to use JavaScript.

However, like any other technology, Blazor has its own set of best practices that developers should follow in order to create the most efficient and secure applications. In this article, we’ll discuss 10 Blazor best practices that developers should keep in mind when developing their applications.

1. Use the Blazor component model

The Blazor component model is a way of structuring the UI of an application into reusable, composable components. This allows developers to create complex UIs from smaller pieces that can be reused and recombined in different ways. It also makes it easier to maintain code since changes only need to be made in one place instead of multiple places throughout the application.

Using the Blazor component model also helps with performance. By breaking down the UI into smaller components, each component can be rendered independently, which reduces the amount of data sent over the network and improves overall page load times. Additionally, components can be cached on the client-side, so they don’t have to be re-downloaded every time the page is loaded.

Blazor components are also easy to test. Since components are self-contained, they can be tested individually without having to worry about other parts of the application. This makes it much easier to ensure that components are working correctly before deploying them to production.

2. Minimize JavaScript interop calls

JavaScript interop calls are necessary when using Blazor to access browser APIs that aren’t available in .NET. However, they can be expensive and slow down the performance of your application. This is because each time a JavaScript interop call is made, it requires a round-trip from the client to the server and back again. This adds latency to the user experience, which can lead to poor performance.

To minimize the number of JavaScript interop calls, you should first identify any areas where you can use native .NET code instead of relying on JavaScript. For example, if you need to access the DOM, consider using the built-in Blazor components or libraries like Blazorise instead of making a JavaScript interop call. If you do need to make an interop call, try to batch them together into fewer requests. This will reduce the amount of overhead associated with each request.

You can also take advantage of caching techniques to improve performance. By caching the results of JavaScript interop calls, you can avoid having to make multiple requests for the same data. Additionally, you can use lazy loading to only load the data when it’s needed, rather than preloading all of the data upfront.

3. Prefer server-side rendering over client-side

Server-side rendering is the process of generating HTML on the server and sending it to the client. This approach has several advantages over client-side rendering, which involves running JavaScript code in the browser to generate HTML.

The first advantage of server-side rendering is improved performance. Server-side rendering eliminates the need for a round trip from the client to the server, as all the HTML is generated on the server before being sent to the client. This reduces latency and improves page load times. Additionally, since the HTML is already rendered when it reaches the client, there is no need for additional processing by the browser, resulting in faster page loads.

The second advantage of server-side rendering is better SEO. Search engine crawlers are not able to execute JavaScript, so they cannot index content that is only available through client-side rendering. With server-side rendering, however, the HTML is already generated and can be indexed by search engines, improving your website’s visibility.

The third advantage of server-side rendering is improved security. Since the HTML is generated on the server, malicious scripts or other malicious code cannot be injected into the page. This makes it much harder for attackers to inject malicious code into your webpages.

To use server-side rendering with Blazor, you must configure your application to run on the server. You can do this by setting the “RazorCompileOnBuild” property to true in your project file. This will cause the Razor compiler to compile your pages at build time, ensuring that the HTML is generated on the server. Additionally, you should set the “RazorPagesAssemblyName” property to the name of your assembly, so that the Razor compiler knows where to look for your pages. Once these properties have been configured, you can start using server-side rendering in your Blazor applications.

4. Keep your components stateless and use services for state management

The main benefit of keeping components stateless is that it makes them easier to test and debug. When a component has no internal state, you can easily create tests for its behavior without having to worry about setting up the correct initial conditions or dealing with any side effects from previous interactions. This also makes it much simpler to identify bugs in your code since there are fewer variables to consider.

Using services for state management allows you to keep your components decoupled from each other. By using a service layer, you can ensure that changes made in one component don’t affect the behavior of another. This helps to make sure that your application remains maintainable and extensible over time.

Services also provide an easy way to share data between components. Instead of passing data through props or events, you can use a service to store the data and then inject it into any component that needs it. This makes it much easier to manage complex applications with multiple components that need access to the same data.

5. Leverage built-in validation attributes

When using Blazor, validation attributes are used to ensure that user input is valid before it is sent to the server. This helps prevent malicious data from being submitted and ensures that only valid data is accepted. Validation attributes can be applied directly to HTML elements or components in order to validate user input.

The built-in validation attributes provided by Blazor make it easy to quickly add validation rules to your application without having to write custom code. These attributes include Required, Range, MinLength, MaxLength, RegularExpression, Compare, EmailAddress, and more. Each of these attributes has a specific purpose and can be used to validate different types of user input. For example, the Required attribute will ensure that a field is not left blank, while the Range attribute will check if a value falls within a specified range.

Using the built-in validation attributes also makes it easier to maintain your application since you don’t have to manually update any custom validation logic when changes are made. Additionally, they provide an intuitive way for users to understand what type of data is expected from them. By leveraging the built-in validation attributes, developers can easily create robust applications with minimal effort.

6. Make sure to dispose of resources when they are no longer needed

When a Blazor component is no longer needed, it should be disposed of to free up resources. This is especially important when dealing with components that use external resources such as databases or web services. If these resources are not properly disposed of, they can remain in memory and cause performance issues.

To ensure proper disposal of resources, the Dispose() method should be called on any objects that implement IDisposable. This will release any unmanaged resources associated with the object. Additionally, any event handlers registered by the component should also be unregistered. This will prevent them from being triggered after the component has been disposed.

It’s also important to make sure that all child components are disposed of when their parent component is disposed. To do this, the OnDisposing() method should be overridden in the parent component and used to call the Dispose() method on each of its children. This ensures that all resources associated with the component tree are released.

Furthermore, if the component uses an async task, then the Cancel() method should be called on the task before disposing of the component. This will stop the task from running and allow the resources associated with it to be freed up.

7. Leverage the new CSS isolation feature in Blazor

CSS isolation is a feature that allows developers to scope their CSS styles to specific components. This means that the styles applied to one component will not affect any other components, and vice versa. This helps prevent conflicts between different components on the same page, as well as making it easier to maintain and debug code.

The way this works in Blazor is by using the @key directive. The @key directive takes a unique identifier for each component, which can be used to create a scoped style sheet. For example, if you have two components with the same class name, but they are given different keys, then the styles applied to one component will not affect the other.

This makes it much easier to manage complex applications, since you don’t have to worry about conflicting styles from different components. It also makes debugging simpler, since you can easily identify which component is causing an issue.

8. Use code splitting to reduce initial download size

Code splitting is a technique that allows developers to split their code into smaller chunks, which can then be loaded on demand. This means that instead of downloading the entire application at once, users only download the parts they need when they need them. This reduces the initial download size and improves performance by reducing the amount of data that needs to be transferred over the network.

Blazor makes it easy to implement code splitting with its built-in routing system. By using route parameters, developers can create separate routes for each page or component in their application. When a user navigates to a specific page or component, Blazor will automatically load the associated code chunk. This ensures that only the necessary code is downloaded, resulting in faster loading times and reduced bandwidth usage.

Additionally, code splitting also helps improve caching efficiency. Since each code chunk is stored separately, browsers are able to cache individual components more effectively. This means that if a user visits multiple pages within an application, they won’t have to re-download the same code every time. Instead, the browser will simply retrieve the cached version from memory, resulting in improved performance.

9. Take advantage of dependency injection

Dependency injection (DI) is a software design pattern that allows for the decoupling of components in an application. It enables developers to create loosely coupled code, which makes it easier to maintain and test applications. DI also helps reduce the amount of boilerplate code needed to wire up components.

When using Blazor, taking advantage of dependency injection can help make your code more organized and maintainable. By injecting services into components, you can easily access them from anywhere in the component tree without having to manually pass them around. This reduces the need for complex wiring logic and makes it easier to refactor components.

Additionally, DI makes it easy to swap out implementations of services at runtime. For example, if you have a service that needs to be mocked during testing, you can inject a mock implementation instead of the real one. This makes it much easier to write unit tests for components.

Blazor provides built-in support for dependency injection through its ServiceProvider class. The ServiceProvider class allows you to register services with the framework and then inject them into components as needed. You can also use third-party libraries such as Autofac or Microsoft’s own Dependency Injection library to manage dependencies.

10. Leverage shared projects for common code

Shared projects are a great way to share code between multiple Blazor applications. This is because they allow you to create a single project that can be referenced by multiple other projects, and any changes made in the shared project will automatically be reflected in all of the referencing projects. This makes it much easier to maintain common code across multiple applications, as any changes only need to be made once in the shared project.

Using shared projects also helps with organization, as all of the common code can be kept in one place. This makes it easier to find and manage the code, as well as making it simpler for developers to understand how the code works. Additionally, since the code is stored in a single location, it’s easy to keep track of which version of the code is being used in each application.

When using shared projects, it’s important to ensure that the code is properly organized and structured. This means creating separate folders for different types of code, such as models, services, and components. It also means ensuring that the code is properly commented so that it’s easy to understand what each piece of code does. Finally, it’s important to make sure that the code is tested thoroughly before deploying it to production.