// Internal for testing.
internal async Task RunAsyncCore(CancellationToken cancellationToken)
{
if (_started)
{
throw new InvalidOperationException("The host has already started.");
}
_started = true;
CultureProvider.ThrowIfCultureChangeIsUnsupported();
// EntryPointInvoker loads satellite assemblies for the application default culture.
// Application developers might have configured the culture based on some ambient state
// such as local storage, url etc as part of their Program.Main(Async).
// This is the earliest opportunity to fetch satellite assemblies for this selection.
await CultureProvider.LoadCurrentCultureResourcesAsync();
var tcs = new TaskCompletionSource <object>();
using (cancellationToken.Register(() => { tcs.TrySetResult(null); }))
{
var loggerFactory = Services.GetRequiredService <ILoggerFactory>();
_renderer = new WebAssemblyRenderer(Services, loggerFactory);
var rootComponents = _rootComponents;
for (var i = 0; i < rootComponents.Length; i++)
{
var rootComponent = rootComponents[i];
await _renderer.AddComponentAsync(rootComponent.ComponentType, rootComponent.Selector, rootComponent.Parameters);
}
await tcs.Task;
}
}
public static int Add(WebAssemblyRenderer renderer)
{
var id = _nextId++;
_renderers?.Add(id, renderer);
return(id);
}
public Task StartAsync(CancellationToken cancellationToken = default)
{
// We need to do this as early as possible, it eliminates a bunch of problems. Note that what we do
// is a bit fragile. If you see things breaking because JSRuntime.Current isn't set, then it's likely
// that something on the startup path went wrong.
//
// We want to the JSRuntime created here to be the 'ambient' runtime when JS calls back into .NET. When
// this happens in the browser it will be a direct call from Mono. We effectively needs to set the
// JSRuntime in the 'root' execution context which implies that we want to do as part of a direct
// call from Program.Main, and before any 'awaits'.
JSRuntime.SetCurrentJSRuntime(_runtime);
SetBrowserHttpMessageHandlerAsDefault();
var scopeFactory = Services.GetRequiredService <IServiceScopeFactory>();
_scope = scopeFactory.CreateScope();
try
{
var startup = _scope.ServiceProvider.GetService <IBlazorStartup>();
if (startup == null)
{
var message =
$"Could not find a registered Blazor Startup class. " +
$"Using {nameof(IWebAssemblyHost)} requires a call to {nameof(IWebAssemblyHostBuilder)}.UseBlazorStartup.";
throw new InvalidOperationException(message);
}
// Note that we differ from the WebHost startup path here by using a 'scope' for the app builder
// as well as the Configure method.
var builder = new WebAssemblyBlazorApplicationBuilder(_scope.ServiceProvider);
startup.Configure(builder, _scope.ServiceProvider);
_renderer = builder.CreateRenderer();
}
catch
{
_scope.Dispose();
_scope = null;
if (_renderer != null)
{
_renderer.Dispose();
_renderer = null;
}
throw;
}
return(Task.CompletedTask);
}
public Task StopAsync(CancellationToken cancellationToken = default)
{
if (_scope != null)
{
_scope.Dispose();
_scope = null;
}
if (_renderer != null)
{
_renderer.Dispose();
_renderer = null;
}
return(Task.CompletedTask);
}
private async Task StartAsyncAwaited()
{
var scopeFactory = Services.GetRequiredService <IServiceScopeFactory>();
_scope = scopeFactory.CreateScope();
try
{
var startup = _scope.ServiceProvider.GetService <IBlazorStartup>();
if (startup == null)
{
var message =
$"Could not find a registered Blazor Startup class. " +
$"Using {nameof(IWebAssemblyHost)} requires a call to {nameof(IWebAssemblyHostBuilder)}.UseBlazorStartup.";
throw new InvalidOperationException(message);
}
// Note that we differ from the WebHost startup path here by using a 'scope' for the app builder
// as well as the Configure method.
var builder = new WebAssemblyBlazorApplicationBuilder(_scope.ServiceProvider);
startup.Configure(builder, _scope.ServiceProvider);
_renderer = await builder.CreateRendererAsync();
}
catch
{
_scope.Dispose();
_scope = null;
if (_renderer != null)
{
_renderer.Dispose();
_renderer = null;
}
throw;
}
}
