Merge pull request #42 from growthbook/adding-async-variations

Added async versions of EvalFeature/GetFeatureValue

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.0.7]
+
+- Added async versions of EvalFeature/GetFeatureValue and a flag on the originals for backwards compatibility.
+
 ## [1.0.6]
 
 - Set hash version with rule

GrowthBook/GrowthBook.cs

@@ -166,9 +166,24 @@ public bool IsOff(string key)
         }
 
         /// <inheritdoc />
-        public T GetFeatureValue<T>(string key, T fallback)
+        public T GetFeatureValue<T>(string key, T fallback, bool alwaysLoadFeatures = false)
         {
-            var value = EvalFeature(key).Value;
+            if (alwaysLoadFeatures)
+            {
+                LoadFeatures().Wait();
+            }
+
+            var result = EvaluateFeature(key);
+            var value = result.Value;
+
+            return value.IsNull() ? fallback : value.ToObject<T>();
+        }
+
+        /// <inheritdoc />
+        public async Task<T> GetFeatureValueAsync<T>(string key, T fallback, CancellationToken? cancellationToken = null)
+        {
+            var result = await EvalFeatureAsync(key, cancellationToken);
+            var value = result.Value;
 
             return value.IsNull() ? fallback : value.ToObject<T>();
         }
@@ -187,8 +202,25 @@ public Action Subscribe(Action<Experiment, ExperimentResult> callback)
         }
 
         /// <inheritdoc />
-        public FeatureResult EvalFeature(string featureId)
+        public FeatureResult EvalFeature(string featureId, bool alwaysLoadFeatures = false)
         {
+            if (alwaysLoadFeatures)
+            {
+                LoadFeatures().Wait();
+            }
+
+            return EvaluateFeature(featureId);
+        }
+
+        public async Task<FeatureResult> EvalFeatureAsync(string featureId, CancellationToken? cancellationToken = null)
+        {
+            await LoadFeatures(cancellationToken: cancellationToken);
+
+            return EvaluateFeature(featureId);
+        }
+
+        private FeatureResult EvaluateFeature(string featureId)
+        { 
             try
             {
                 if (!Features.TryGetValue(featureId, out Feature feature))
@@ -288,7 +320,7 @@ public ExperimentResult Run(Experiment experiment)
 
                 return result;
             }
-            catch(Exception ex)
+            catch (Exception ex)
             {
                 _logger.LogError(ex, $"Encountered an unhandled exception while executing '{nameof(Run)}'");
 

GrowthBook/GrowthBook.csproj

@@ -11,7 +11,7 @@
     <RepositoryUrl>https://github.com/growthbook/growthbook-csharp.git</RepositoryUrl>
     <RepositoryType>git</RepositoryType>
     <PackageTags>GrowthBook,A/B test,feature toggle,flag</PackageTags>
-    <Version>1.0.6</Version>
+    <Version>1.0.7</Version>
     <Title>GrowthBook C# SDK</Title>
     <PackageProjectUrl>https://www.growthbook.io/</PackageProjectUrl>
     <PackageReadmeFile>README.md</PackageReadmeFile>

GrowthBook/IGrowthBook.cs

@@ -25,13 +25,28 @@ public interface IGrowthBook : IDisposable
         bool IsOff(string key);
 
         /// <summary>
-        /// Gets the value of a feature cast to the specified type.
+        /// Gets the value of a feature cast to the specified type. This is a blocking operation and should not be used from a UI thread.
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="key">The feature key.</param>
         /// <param name="fallback">Fallback value to return if the feature is not on.</param>
+        /// <param name="alwaysLoadFeatures">
+        /// Loads all features from the repository/cache prior to executing.
+        /// This is included for backwards compatibility and, when set to true, becomes a blocking operation and should not be used from a UI thread.
+        /// If possible, please use the async version of this method: <see cref="GetFeatureValueAsync{T}(string, T, CancellationToken?)"/>
+        /// </param>
         /// <returns>Value of a feature cast to the specified type.</returns>
-        T GetFeatureValue<T>(string key, T fallback);
+        T GetFeatureValue<T>(string key, T fallback, bool alwaysLoadFeatures = false);
+
+        /// <summary>
+        /// Asynchronously gets the value of a feature cast to the specified type.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="key">The feature key.</param>
+        /// <param name="fallback">Fallback value to return if the feature is not on.</param>
+        /// <param name="cancellationToken">The cancellation token for this operation.</param>
+        /// <returns>Value of a feature cast to the specified type.</returns>
+        Task<T> GetFeatureValueAsync<T>(string key, T fallback, CancellationToken? cancellationToken = null);
 
         /// <summary>
         /// Returns a map of the latest results indexed by experiment key.
@@ -51,8 +66,21 @@ public interface IGrowthBook : IDisposable
         /// Evaluates a feature and returns a feature result.
         /// </summary>
         /// <param name="key">The feature key.</param>
+        /// <param name="alwaysLoadFeatures">
+        /// Loads all features from the feature repository/cache prior to executing.
+        /// This is included for backwards compatibility and, when set to true, becomes a blocking operation and should not be used from a UI thread.
+        /// If possible, please use the async version of this method: <see cref="EvalFeatureAsync(string, CancellationToken?)"/>
+        /// </param>
+        /// <returns>The feature result.</returns>
+        FeatureResult EvalFeature(string key, bool alwaysLoadFeatures = false);
+
+        /// <summary>
+        /// Asynchronously loads and evaluates a feature and returns a feature result.
+        /// </summary>
+        /// <param name="featureId">The feature ID.</param>
+        /// <param name="cancellationToken">The cancellation token for the operation.</param>
         /// <returns>The feature result.</returns>
-        FeatureResult EvalFeature(string key);
+        Task<FeatureResult> EvalFeatureAsync(string featureId, CancellationToken? cancellationToken = null);
 
         /// <summary>
         /// Evaluates an experiment and returns an experiment result.