garfieldmoore/Feature-Toggle

Feature toggling api

Feature-Toggle

Toggler provides a minimum, and friction free feature toggling API.

To get started simply add the package to your application;

  install-package toggler.net

This will add the below configuration section to your app.config;

  <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="FeatureConfiguration" type="Toggles.Configuration.Providers.ConfigurationSection.FeatureConfiguration, Toggler" />
  </configSections>

  <FeatureConfiguration>
    <Features>
      <add name="FeatureA" isAvailable="true"/>
      <add name="FeatureB" isAvailable="false"/>
    </Features>
  </FeatureConfiguration>

Now you can start toggling features;

  if (Features.IsAvailable("FeatureA"))
  {
      // Do something useful
      Console.WriteLine("FeatureA is enabled.");
  }

However, one of the principles behind toggler is extensibility...

Extending Toggler

Removing magic strings

Defining extension methods on the Features class reduces duplication;

internal static class ToggleExtensions
{
    public static bool IsMyNewFeatureEnabled(this Features features)
    {
        return Features.IsAvailable("FeatureA");
    }
}

Now I can check what features are enabled;

var features = new Features();
if (features.IsMyNewFeatureEnabled())
{
    Console.WriteLine("My new Feature is enabled.");                
}

Using different providers

The example below extends the framework to provide feature toggles from an in-memory configuration provider.

public class ExtendingToggler
{
    [Test]
    public void Should_allow_new_providers()
    {
        Features.Initialize(new InMemorySwitchProviderFactory());

        Features.IsAvailable("Feature1").ShouldBe(true);
        Features.IsAvailable("Feature2").ShouldBe(false);
    }
}

public class InMemorySwitchProviderFactory : ISwitchProviderFactory
{
    public IProvideSwitches Create()
    {
        return new InMemorySwitchProvider();
    }
}

public class InMemorySwitchProvider : FeatureSwitchProvider
{
    public override void ReadConfiguration()
    {
        FeatureSwitches.Add("Feature1", new Feature() { Name = "Feature1", State = true });
        FeatureSwitches.Add("Feature2", new Feature() { Name = "Feature1", State = false });
    }
}