OpenStackNet.Configuring event replaces OpenStackNet.Configure

* Allow multiple persons to configure things without a master
  coordinator.
* Finalization of configuration is still triggered when
  OpenStackNet.Configuration is accessed.

Author: carolynvs

src/corelib/Extensions/FlurlExtensions.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Net;
 using System.Net.Http;

src/corelib/OpenStackNet.cs

@@ -19,7 +19,7 @@ public static class OpenStackNet
     {
         /// <summary>
         /// Global configuration which affects OpenStack.NET's behavior.
-        /// <para>Modify using <see cref="Configure(Action{OpenStackNetConfigurationOptions})"/>.</para>
+        /// <para>Customize using the <see cref="Configuring"/> event.</para>
         /// </summary>
         public static OpenStackNetConfigurationOptions Configuration
         {
@@ -36,34 +36,19 @@ public static OpenStackNetConfigurationOptions Configuration
         private static bool _isConfigured;
 
         /// <summary>
-        /// <para>DEPRECATED. This no longer needs to be explicityly called, unless you require customizations. In that case, use <see cref="Configure(Action{OpenStackNetConfigurationOptions})"/> .</para>
-        /// Initializes the SDK using the default configuration.
+        /// Occurs when initializing the global configuration for OpenStack.NET.
         /// </summary>
-        [Obsolete("This will be removed in v2.0. Use Configure(Action{OpenStackNetConfigurationOptions}) instead if you need to customize anything.")]
-        public static void Configure()
-        {
-            Configure(null);
-        }
+        public static event Action<OpenStackNetConfigurationOptions> Configuring;
 
         /// <summary>
-        /// <para>Provides thread-safe accesss to OpenStack.NET's global configuration options.</para>
-        /// <para>Can only be called once at application start-up, before instantiating any OpenStack.NET objects.</para>
-        /// </summary>
-        /// <param name="configure">Additional configuration of OpenStack.NET's global settings.</param>
-        public static void Configure(Action<OpenStackNetConfigurationOptions> configure)
-        {
-            Configure(null, configure);
-        }
-
-        /// <summary>
-        /// <para>DEPRECATED, use <see cref="Configure(Action{OpenStackNetConfigurationOptions})"/> instead.</para>
+        /// <para>DEPRECATED, use the <see cref="Configuring"/> event instead.</para>
         /// <para>Provides thread-safe accesss to OpenStack.NET's global configuration options.</para>
         /// <para>Can only be called once at application start-up, before instantiating any OpenStack.NET objects.</para>
         /// </summary>
         /// <param name="configureFlurl">Addtional configuration of the OpenStack.NET Flurl client settings <seealso cref="Flurl.Http.FlurlHttp.Configure" />.</param>
         /// <param name="configure">Additional configuration of OpenStack.NET's global settings.</param>
-        [Obsolete("This will be removed in v2.0. Use Configure(Action{OpenStackNetConfigurationOptions}) instead.")]
-        public static void Configure(Action<FlurlHttpSettings> configureFlurl, Action<OpenStackNetConfigurationOptions> configure)
+        [Obsolete("This will be removed in v2.0. Use the OpenStackNet.Configuring event instead.")]
+        public static void Configure(Action<FlurlHttpSettings> configureFlurl = null, Action<OpenStackNetConfigurationOptions> configure = null)
         {
             lock (ConfigureLock)
             {
@@ -76,25 +61,30 @@ public static void Configure(Action<FlurlHttpSettings> configureFlurl, Action<Op
                     return;
                 }
 
-                // TODO: Use the line below once we hit 2.0 and configureFlurl is deprecated
-                // _config = new OpenStackNetConfigurationOptions(configure);
-                _config = new OpenStackNetConfigurationOptions(options =>
-                {
-                    configureFlurl?.Invoke(options.FlurlHttpSettings);
-                    configure?.Invoke(options);
-                });
+                // Give the application an opportunity to tweak the default config
+                _config = OpenStackNetConfigurationOptions.Create();
+                Configuring?.Invoke(_config);
+                
+                // Apply legacy custom configuration, removed in 2.0 as it's replaced by the Configuring event
+                configureFlurl?.Invoke(_config.FlurlHttpSettings);
+
+                // Finish configuration and lock it
+                _config.CompleteInitialization();
+
                 _isConfigured = true;
             }
         }
 
         /// <summary>
-        /// Resets all configuration (OpenStack.NET, Flurl and Json.NET) so that <see cref="Configure(Action{OpenStackNetConfigurationOptions})"/> can be called again.
+        /// <par>Resets all configuration (OpenStack.NET, Flurl and Json.NET).</par>
+        /// <para>After this is called, you must re-register any <see cref="Configuring"/> event handlers.</para>
         /// </summary>
         public static void ResetDefaults()
         {
             lock (ConfigureLock)
             {
                 _config = null;
+                Configuring = null;
                 _isConfigured = false;
             }
         }
@@ -144,30 +134,46 @@ private static string SerializeHttpCall(HttpCall httpCall)
 
     /// <summary>
     /// A readonly set of properties that affect OpenStack.NET's behavior.
-    /// <para>To configure, pass a custom action via the static <see cref="OpenStackNet.Configure(Action{OpenStackNetConfigurationOptions})"/> method.</para>
+    /// <para>To customize, register an event handler for <see cref="OpenStackNet.Configuring"/>.</para>
     /// </summary>
     public class OpenStackNetConfigurationOptions
     {
-        private readonly bool _isInitialized;
+        private bool _isInitialized;
         private readonly FlurlHttpSettings _flurlHttpSettings;
         private readonly JsonSerializerSettings _jsonSerializerSettings;
         private readonly List<ProductInfoHeaderValue> _userAgents;
 
         /// <summary/>
-        protected internal OpenStackNetConfigurationOptions(Action<OpenStackNetConfigurationOptions> configure = null)
+        protected OpenStackNetConfigurationOptions()
         {
             _flurlHttpSettings = new FlurlHttpSettings();
             _jsonSerializerSettings = new JsonSerializerSettings();
-            _userAgents = new List<ProductInfoHeaderValue>
-            {
-                new ProductInfoHeaderValue("openstack.net", GetType().GetAssemblyFileVersion())
-            };
+            _userAgents = new List<ProductInfoHeaderValue>();
+        }
+
+        /// <summary />
+        public static event Action<CreateEvent> Creating;
+
+        /// <summary />
+        internal static OpenStackNetConfigurationOptions Create()
+        {
+            var createEvent = new CreateEvent();
+            Creating?.Invoke(createEvent);
+            return createEvent.Result;
+        }
 
-            configure?.Invoke(this);
+        /// <summary />
+        public void CompleteInitialization()
+        {
+            OnCompleteInitialization();
             ApplyDefaults();
             _isInitialized = true;
         }
 
+        /// <summary />
+        protected virtual void OnCompleteInitialization()
+        {}
+
         /// <summary>
         /// Custom Flurl.Http configuration settings which are specific to requests made by this SDK.
         /// </summary>
@@ -215,6 +221,8 @@ private void ApplyDefaults()
             //
             // Apply our default settings on top of user customizations, hopefully without clobbering anything
             //
+            UserAgents.Add(new ProductInfoHeaderValue("openstack.net", GetType().GetAssemblyFileVersion()));
+
             _jsonSerializerSettings.DefaultValueHandling = DefaultValueHandling.Ignore;
             _jsonSerializerSettings.MissingMemberHandling = MissingMemberHandling.Ignore;
             _jsonSerializerSettings.NullValueHandling = NullValueHandling.Ignore;
@@ -257,5 +265,12 @@ private void SetUserAgentHeader(HttpCall call)
                 call.Request.Headers.UserAgent.Add(userAgent);
             }
         }
+
+        /// <summary />
+        public class CreateEvent
+        {
+            /// <summary />
+            public OpenStackNetConfigurationOptions Result = new OpenStackNetConfigurationOptions();
+        }
     }
 }

src/corelib/Testing/HttpTest.cs

@@ -2,7 +2,6 @@
 using System.Net;
 using System.Net.Http;
 using Flurl;
-using Flurl.Http;
 using Flurl.Http.Configuration;
 using Flurl.Http.Content;
 using OpenStack.Authentication;
@@ -21,19 +20,19 @@ public class HttpTest : Flurl.Http.Testing.HttpTest, IDisposable
         /// <summary>
         /// Initializes a new instance of the <see cref="HttpTest"/> class.
         /// </summary>
-        /// <param name="configure">Additional configuration of OpenStack.NET's global settings.</param>
-        public HttpTest(Action<OpenStackNetConfigurationOptions> configure = null)
+        public HttpTest()
         {
-            Action<FlurlHttpSettings> setTestMode = settings =>
+            OpenStackNet.ResetDefaults();
+            OpenStackNet.Configuring += SetTestMode;
+        }
+
+        private void SetTestMode(OpenStackNetConfigurationOptions options)
+        {
+            options.FlurlHttpSettings.HttpClientFactory = new TestHttpClientFactory(this);
+            options.FlurlHttpSettings.AfterCall = call =>
             {
-                settings.HttpClientFactory = new TestHttpClientFactory(this);
-                settings.AfterCall = call =>
-                {
-                    CallLog.Add(call);
-                };
+                CallLog.Add(call);
             };
-            OpenStackNet.ResetDefaults();
-            OpenStackNet.Configure(setTestMode, configure);
         }
 
         /// <inheritdoc />

src/testing/unit/OpenStackNetTests.cs

@@ -30,7 +30,7 @@ public void Dispose()
         public void WhenConfigureIsCalled_GlobalFlurlConfiguration_IsNotAltered()
         {
             // User makes their own tweaks to Flurl
-            Action<HttpCall> customErrorHandler = call => Debug.WriteLine("I saw an erro!");
+            Action<HttpCall> customErrorHandler = call => Debug.WriteLine("I saw an error!");
             FlurlHttp.GlobalSettings.OnError = customErrorHandler;
 
             // We configure openstack.net
@@ -48,7 +48,7 @@ public void WhenConfigureIsCalled_GlobalFlurlConfiguration_IsNotAltered()
         public void WhenResetDefaultsIsCalled_GlobalFlurlConfiguration_IsNotAltered()
         {
             // User makes their own tweaks to Flurl
-            Action<HttpCall> customErrorHandler = call => Debug.WriteLine("I saw an erro!");
+            Action<HttpCall> customErrorHandler = call => Debug.WriteLine("I saw an error!");
             FlurlHttp.GlobalSettings.OnError = customErrorHandler;
 
             // We configure openstack.net
@@ -122,9 +122,14 @@ public async Task UserAgentOnlyListOnceTest()
         [Fact]
         public async Task UserAgentWithApplicationSuffixTest()
         {
-            using (var httpTest = new HttpTest(configure: options =>
-                    options.UserAgents.Add(new ProductInfoHeaderValue("(unittests)"))))
+            using (var httpTest = new HttpTest())
             {
+                // Apply a custom application user agent
+                OpenStackNet.Configuring += options =>
+                {
+                    options.UserAgents.Add(new ProductInfoHeaderValue("(unittests)"));
+                };
+
                 await "http://api.com".PrepareRequest().GetAsync();
 
                 var userAgent = httpTest.CallLog[0].Request.Headers.UserAgent.ToString();