PreRenderComponent
Provides a DI Service and/or a CascadingValue exposing whether the app is in PreRendering or not.
Usage
Install the nuget https://nuget.org/packages/PreRenderComponent
Add the service (Required)
Add the service to your startup Configure method This component has a dependency on HttpContextAccessor, so also add that.
services.AddHttpContextAccessor();
services.AddScoped<IPreRenderFlag,PreRenderFlag>();Consume the service wherever you need it (unless you want to use the Cascading Value component)
@inject PreRenderComponent.IPreRenderFlag PreRenderFlag
@if (PreRenderFlag.IsPreRendering)
{
<h1>Pre-Rendering</h1>
}Cascading Value (Optional)
Wrap the Router component in PreRenderCascade in the App.razor file
<PreRenderComponent.PreRenderCascade>
<Router AppAssembly="typeof(App).Assembly">
<Found Context="routeData">
<RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
</Found>
<NotFound>
<LayoutView Layout="@typeof(MainLayout)">
<p>Sorry, there's nothing at this address.</p>
</LayoutView>
</NotFound>
</Router>
</PreRenderComponent.PreRenderCascade>Consume the CascadingValue in your own pages/components
@if (IsPreRendering)
{
<button class="btn btn-dark" onclick="@IncrementCount" disabled>Don't Click me</button>
}
else
{
<button class="btn btn-primary" onclick="@IncrementCount">Click me</button>
}
@code {
[CascadingParameter(Name = "PreRendering")]
protected bool IsPreRendering { get; set; }
}