Aspnetcore.docs: Under "Conditionally enable runtime compilation" Env is coming as NULL

[esausilva]

Documentation does not say where to assign Env.

Just following the documentation as as is under "Conditionally enable runtime compilation" throws a null reference exception when trying to use Env.IsDevelopment().

I had to assign Env as below

public Startup(IConfiguration configuration, IWebHostEnvironment env) {
    Configuration = configuration;
    Env = env;
}

Then I am able to use Env.IsDevelopment() without throwing a null reference exception.

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Document Details

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• ID: 8a83deb2-e035-bb66-be4f-68709bcad341
• Version Independent ID: 16438f35-f35d-c097-0903-ec17e83e051e
• Content: Razor file compilation in ASP.NET Core
• Content Source: aspnetcore/mvc/views/view-compilation.md
• Product: aspnet-core
• Technology: aspnetcore-mvc
• GitHub Login: @Rick-Anderson
• Microsoft Alias: riande

[Rick-Anderson]

Create a new project - which shows the correct usage.

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapRazorPages();
            });
        }

You're right, I'll get his updated.

[scottaddie]

The following sample app shows how to do it: https://github.com/aspnet/samples/tree/master/samples/aspnetcore/mvc/runtimecompilation

[esausilva]

@scottaddie Thank you. That is exactly what I did. I wanted to make sure I was doing it the correct way 👍

I hope the Docs get updated for other people having the same problem

[Rick-Anderson]

@esausilva I'll get it updated this week. Thanks for reporting the problem.

[nzcoward]

@scottaddie - in the sample is it perhaps better to remove the env parameter from the Configure method? Else it feels like the class level property might be a different IWebHostEnvironment.

Unsure if you're a maintainer, but have created a PR showing my thoughts.

[scottaddie]

@nzcoward Let's see what @pranavkm thinks of your proposal.

[pranavkm]

Sure, done.

[nmg196]

Not sure why 3 months on, the docs are still not correct :(