144 words (approximately 1 min)

Overview

By default, when the app launches, all assemblies are automatically downlaoded from the web server. Blazor can be instructed to postpone downloading an assembly.

Implementation Steps

1. Register the Lazily-Loaded Assemblies in Project File

csproj

<ItemGroup>
    <BlazorWebAssemblyLazyLoad Include="ExampleProject.dll" />
</ItemGroup>

2. Make Changes to Router in App.razor

App.razor

<!-- Inject LazyAssemblyLoader which is automatically registered with DI by the framework -->
@using Microsoft.AspNetCore.WebAssembly.Services
@inject LazyAssemblyLoader

<Router AppAssembly="@typeof(App).Assembly" AdditionalAssemblies="@lazyLoadedAssemblies"
        OnNavigateAsync="@OnNavigateAsync">
    ...
</Router>

@code
{
    private List<Assembly> lazyLoadedAssemblies = new();

    private async Task OnNavigateAsync(NavigationContext args)
    {
        // check if we are navigating to the detail page for the first time
        if (args.path.Contains("employeedetail"))
        {
            // use js-interop to make an async network call and retrieve the
            // array of assemblies to be loaded lazily:
            var assemblies = await LazyAssemblyLoader.LoadAssembliesAsync(
                new string[] { "BethanysPieShop.ComponentsLibrary.dll" }
            )
            
            // add those assemblies to the List<Assembly>:
            lazyLoadAssemblies.AddRange(assemblies);
        }
    }
}