Microsoft.FeatureManagement Updates

The packages associated with this release are

Preview Release

A new set of APIs has been added to support dynamic features. The dynamic feature experience can be considered to be in preview.

Features

Dynamic Features

Dynamic features are a tool that can be used to surface different variants of a feature to different segments of an audience. Previously, this library only worked with feature flags. Feature flags are limited to boolean values, as they are either enabled or disabled. Dynamic features have dynamic values. They can be string, int, a complex object, or any other type.

//
// Modify view based off multiple possible variants
model.BackgroundUrl = dynamicFeatureManager.GetVariantAsync<string>("HomeBackground", cancellationToken);

return View(model);

For more details read here.

Cancellation token support

Version 2 of Microsoft.FeatureManagement has an asynchronous pipeline, but cancellation token support was not added. Adding support for this in v2 would have required changing interfaces, thus a breaking change. V3 introduces this breaking change, and now proper cancellation is supported through the pipeline.

New Configuration Schema

The original schema of the "FeatureManagement" configuration section treated all sub objects as feature flags. Now there are dynamic features alongside feature flags. Additionally, there are other switches that are expected to be added in the future to customize global feature management state. To make room for this the schema has been updated.

{
    "FeatureManagement": {
        "FeatureFlags": {
        },
        "DynamicFeatures": {
        }
    }
}