4.0.0

4.0.0 - November 1, 2024

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 4.0.0
• Microsoft.FeatureManagement.AspNetCore 4.0.0
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights 4.0.0

Microsoft.FeatureManagement

Enhancements

Variant Feature Flags

A variant feature flag is an enhanced feature flag that supports multiple states or variations. While it can still be toggled on or off, it also allows for different configurations, ranging from simple primitives to complex JSON objects. Variant feature flags are particularly useful for feature rollouts, configuration rollouts, and feature experimentation (also known as A/B testing).

The new IVariantFeatureManager has been introduced as the successor to the existing IFeatureManager. It retains all the functionalities of IFeatureManager while adding new GetVariantAsync methods and supporting CancellationToken for all methods.

IVariantFeatureManager featureManager;
...
Variant variant = await featureManager.GetVariantAsync(MyFeatureFlags.HelpText, CancellationToken.None);
model.Text = variant.Configuration.Value;

Note: If reading variant flags from App Configuration, version 8.0.0 or above for the Microsoft.Extensions.Configuration.AzureAppConfiguration or Microsoft.Azure.AppConfiguration.AspNetCore package is required.

For more details on Variants, see here.

Variant Service Provider

Variant feature flags can be used in conjunction with dependency injection to surface different implementations of a service for different users. This is accomplished by using the Variant Service Provider.

For more details on Variant Service Provider, see here

Telemetry

Telemetry provides observability into flag evaluations, offering insights into which users received specific flag results. This enables more powerful metric analysis, such as experimentation.

For more details on Telemetry, see here.

Microsoft Feature Management Schema

Added support for variant feature flags defined using Microsoft Feature Management schema. Variants and telemetry can be declared using Microsoft Feature Flag schema v2. Here is a Sample.

Performance Optimizations

The performance of the feature flag state evaluation has been improved by up to 20%, with a memory reduction of up to 30% for .NET 8 applications compared to the version 3.5.0 release.

Microsoft.FeatureManagement.AspNetCore

Enhancements

• Adjusted the .WithTargeting() builder method to automatically add HttpContextAccessor if it's not already added.

• Added TargetingHttpContextMiddleware which persists targeting context in the current activity. This is used when setting up Telemetry.

• Added support for variants in FeatureTagHelper. This allows MVC views to use the <feature> tag to conditionally render content based on whether a specific variant of a feature is assigned.

  <feature name="FeatureX" variant="Alpha">
    <p>This can only be seen if variant 'Alpha' of 'FeatureX' is assigned.</p>
  </feature>

  For more details on ASP.NET views and variants, see here.

• Updated Microsoft.FeatureManagement reference to 4.0.0. See the release notes for more information on the changes.

• Added support for .NET 9 as a target framework.

Breaking Change

• The FeatureTagHelper constructor now requires an IVariantFeatureManager to support new variant functionality. While this class is typically not instantiated directly, any direct instantiation will need to be updated.
• Removed .NET 7 as a target framework as .NET 7 is out of support.

Microsoft.FeatureManagement.Telemetry.ApplicationInsights

Enhancements

• Added support for Application Insights telemetry. To publish feature flag evaluation data and tag outgoing events with targeting information, register the Application Insights telemetry publisher as shown below.

  builder.Services.AddFeatureManagement()
      .AddApplicationInsightsTelemetry();

  For more details on Application Insights Publishing, see here

4.0.0-preview5

4.0.0-preview5 - Oct 24, 2024

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 4.0.0-preview5
• Microsoft.FeatureManagement.AspNetCore 4.0.0-preview5
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights 4.0.0-preview5

Microsoft.FeatureManagement

Enhancements

• Added support for injecting additional telemetry fields on feature evaluation events if telemetry is enabled.
  • DefaultWhenEnabled reflects what the DefaultWhenEnabled variant on the flag is.
  • VariantAssignmentPercentage shows what percentage of users will be allocated the given Variant for the given Reason.

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview5.

Microsoft.FeatureManagement.Telemetry.ApplicationInsights

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview5.

3.5.0

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 3.5.0
• Microsoft.FeatureManagement.AspNetCore 3.5.0

Microsoft.FeatureManagement

• No changes in this release.

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 3.5.0.

Enhancements

• Introduced an overloaded extension method WithTargeting() for ASP.NET Core applications. It registers a default ITargetingContextAccessor that constructs user context based on the authenticated user of a request. #466

4.0.0-preview4

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 4.0.0-preview4
• Microsoft.FeatureManagement.AspNetCore 4.0.0-preview4
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights 4.0.0-preview4

Microsoft.FeatureManagement

Enhancements

• The feature flag telemetry pipeline is now integrated with .NET Acitivity instrumentation. Feature manager now has an AcitvitySource called "Microsoft.FeatureManagement". If telemetry is enabled for a feature flag, whenever the feature flag is evaluated, feature manager will start an Activity and add an ActivityEvent with tags containing feature evaluation information. #455

Breaking Changes

• If you were using earlier preview versions of this package and configuration files to define variant feature flags, they are no longer supported in the .NET Feature Management schema. Instead, please use the Microsoft Feature Management schema to define variant feature flags. #421.

• AddTelemetryPublisher API and ITelemetryPublisher interface were removed. The feature flag telemetry pipeline is now integrated with .NET Acitivity instrumentation. #455

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview4.

Microsoft.FeatureManagement.Telemetry.ApplicationInsights

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview4.

Enhancements

• Introduced a new API AddApplicationInsightsTelemetryPublisher to register a feature flag telemetry publisher for Application Insights. #455

  builder.Services.AddFeatureManagement()
                  .WithTargeting()
                  .AddApplicationInsightsTelemetryPublisher();

Breaking Changes

• The TargetingTelemetryInitializer type has been moved to this package from the now-deprecated Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore package. This change simplifies the utilization of feature flag telemetry.

• The type ApplicationInsightsTelemetryPublisher has been removed as its functionality has been replaced with the new API AddApplicationInsightsTelemetryPublisher for publishing feature flag telemetry to Application Insights. #455

3.4.0

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 3.4.0
• Microsoft.FeatureManagement.AspNetCore 3.4.0

Microsoft.FeatureManagement

Enhancements

• All public classes no longer use init-only setters, ensuring compatibility with application using C# 7 or earlier. #450

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 3.4.0.

3.3.1

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 3.3.1
• Microsoft.FeatureManagement.AspNetCore 3.3.1

Microsoft.FeatureManagement

Bug fixes

• Fixed a bug that TimeWindowFilter would be registered repeatedly when calling AddFeatureFilter<TimeWindowFilter> after the call of AddFeatureManagement(). #447

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 3.3.1.

3.3.0

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 3.3.0
• Microsoft.FeatureManagement.AspNetCore 3.3.0

Microsoft.FeatureManagement

Enhancements

• Added a Recurrence option to the TimeWindow filter to support recurring time window. This enables scenarios where a feature flag is activated based on a recurrence pattern, such as every day after 5 PM or every Friday. See more details here. (#266)
• A LoggerFactory is no longer required when constructing built-in filters. (#386)

Bug fixes

• Fixed a possible null-reference exception when enumerating GetFeatureNamesAsync. (#438)

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 3.3.0.

4.0.0-preview3

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 4.0.0-preview3
• Microsoft.FeatureManagement.AspNetCore 4.0.0-preview3
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights 4.0.0-preview3
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore 4.0.0-preview3

Microsoft.FeatureManagement

Enhancements

• Added support for variant feature flags defined using Microsoft Feature Management schema. Variants and telemetry can be declared using Microsoft Feature Flag schema v2. The Microsoft Feature Management schema is designed to be language agnostic, enabling you to apply a consistent feature management configuration across Microsoft feature management libraries of different programming languages.

Microsoft.FeatureManagement.AspNetCore

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview3.

Microsoft.FeatureManagement.Telemetry.ApplicationInsights

Breaking Changes

• Updated the namespace for ApplicationInsightsTelemetryPublisher to Microsoft.FeatureManagement.Telemetry. In the future, developers using any of our offered telemetry publishers will no longer need to specify the service specific namespaces like using Microsoft.FeatureManagement.Telemetry.ApplicationInsights.

• Updated the namespace for TrackEvent extension method of TelemetryClient to Microsoft.ApplicationInsights. The previous directive using Microsoft.FeatureManagement.Telemetry.ApplicationInsights is no longer required when calling the TrackEvent method.

Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore

• Updated Microsoft.FeatureManagement reference to 4.0.0-preview3.

4.0.0-preview2

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 4.0.0-preview2
• Microsoft.FeatureManagement.AspNetCore 4.0.0-preview2
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights 4.0.0-preview2
• Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore 4.0.0-preview2

Microsoft.FeatureManagement

Enhancements

• Added support for variant feature flag-based service provider in dependency injection. It allows different service implementations to be injected automatically for different targeted audiences based on their variant assignment. (#39). See more details here.
• Added a TargetingContext property to the EvaluationEvent. This allows feature evaluation events to accurately represent what the targeting context was at the time of feature evaluation. (#409)

Microsoft.FeatureManagement.AspNetCore

Enhancements

• Introduced a new ASP.NET Core middleware called TargetingHttpContextMiddleware. It makes targeting information available from HttpContext on each request. (#409)
• Added support for .NET 8 target framework. (#364)

Microsoft.FeatureManagement.Telemetry.ApplicationInsights

Enhancements

• Added a TargetingId property to the feature evaluation events sent to Application Insights. The TargetingId is the identifier of a targeted user during feature evaluation. This new property allows you to correlate feature evaluation events with other telemetry data your application sends to Application Insights, as long as they share the same TargetingId. (#409)

Microsoft.FeatureManagement.Telemetry.ApplicationInsights.AspNetCore

Enhancements

• Introduced a telemetry initializer named TargetingTelemetryInitializer. It automatically adds targeting information to telemetry data your application sends to Application Insights. This can be used to correlate your telemetry data with feature evaluation events based on the targeting information during your telemetry analysis. (#409)

3.2.0

Microsoft.FeatureManagement Updates

The packages associated with this release are

• Microsoft.FeatureManagement 3.2.0
• Microsoft.FeatureManagement.AspNetCore 3.2.0

Enhancements

• Added support for feature flags defined using Microsoft Feature Management schema