Skip to content
Cratis

Set invariant culture in Cratis Arc.Core services

Set invariant default cultures in a Cratis.Arc.Core service when culture-sensitive parsing and formatting should not depend on the machine’s regional settings. Invariant culture supplies a shared set of conventions; code that explicitly selects another culture still uses that choice.

Why Invariant Culture?

Section titled “Why Invariant Culture?”

A worker parsing the same decimal text on two machines can interpret it differently if each machine supplies a different current culture. Setting an invariant default removes that dependency for operations that use the current culture.

Number formatting and parsing then use invariant conventions, including . as the decimal separator. Date formatting and parsing also use invariant conventions, but the setting does not select a time zone. Culture-sensitive string comparisons and sorting use invariant rules; they do not become ordinal comparisons. Serialization still follows each serializer’s contract and explicit options.

Configuration

Section titled “Configuration”

For an ArcApplication console service or worker, set both default thread cultures before building the application:

using System.Globalization;
using Cratis.Arc;


CultureInfo.DefaultThreadCurrentCulture = CultureInfo.InvariantCulture;
CultureInfo.DefaultThreadCurrentUICulture = CultureInfo.InvariantCulture;


var builder = ArcApplication.CreateBuilder(args);
builder.AddCratisArc();


var app = builder.Build();
app.UseCratisArc();


await app.RunAsync();

For a generic .NET host built with IHostBuilder, UseInvariantCulture() sets the same defaults in one call. This fragment builds the host; it does not start it or activate Arc HTTP endpoints:

using Cratis.Arc;
using Microsoft.Extensions.Hosting;


var host = Host.CreateDefaultBuilder(args)
    .UseInvariantCulture()
    .Build();

What Gets Configured

Section titled “What Gets Configured”

Both approaches set:

  • CultureInfo.DefaultThreadCurrentCulture to CultureInfo.InvariantCulture
  • CultureInfo.DefaultThreadCurrentUICulture to CultureInfo.InvariantCulture

These properties supply defaults for threads, including background and thread-pool threads, that have not been assigned a culture explicitly. They do not override an explicit culture set by application code.

When to Use

Section titled “When to Use”

Use invariant defaults for workers and backend data processing when machine-local formatting is not part of the input or output contract. This is useful when the same service runs on machines with different regional settings.

If a service accepts localized user input or produces localized output, choose that culture explicitly at the parsing or formatting boundary. An invariant process default does not replace the user’s locale, a time-zone decision, or an explicit serialization contract.

ASP.NET Core Applications

Section titled “ASP.NET Core Applications”

For an ASP.NET Core application, use its WebApplicationBuilder extension instead. That setup also configures request localization middleware; follow Invariant Culture for ASP.NET Core rather than applying this host’s setup to web requests.

Community: Discord