Support reading API version from URL segment. Fixes #91

Chris Martinez · Chris Martinez · commit d48c835efc18 · 2017-03-03T07:16:15.000-08:00
diff --git a/src/Common/Versioning/UrlSegmentApiVersionReader.cs b/src/Common/Versioning/UrlSegmentApiVersionReader.cs
@@ -0,0 +1,25 @@
+﻿#if WEBAPI
+namespace Microsoft.Web.Http.Versioning
+#else
+namespace Microsoft.AspNetCore.Mvc.Versioning
+#endif
+{
+#if WEBAPI
+    using Routing;
+#else
+    using Microsoft.AspNetCore.Routing;
+    using Routing;
+#endif
+    using System.Diagnostics.Contracts;
+
+    /// <summary>
+    /// Represents a service API version reader that reads the value from a path segment in the request URL.
+    /// </summary>
+    public partial class UrlSegmentApiVersionReader : IApiVersionReader
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UrlSegmentApiVersionReader"/> class.
+        /// </summary>
+        public UrlSegmentApiVersionReader() { }
+    }
+}
diff --git a/src/Microsoft.AspNet.WebApi.Versioning/Routing/ApiVersionRouteConstraint.cs b/src/Microsoft.AspNet.WebApi.Versioning/Routing/ApiVersionRouteConstraint.cs
@@ -1,6 +1,5 @@
 ﻿namespace Microsoft.Web.Http.Routing
 {
-    using System;
     using System.Collections.Generic;
     using System.Net.Http;
     using System.Web.Http;
@@ -25,22 +24,36 @@ public sealed class ApiVersionRouteConstraint : IHttpRouteConstraint
         /// <returns>True if the route constraint is matched; otherwise, false.</returns>
         public bool Match( HttpRequestMessage request, IHttpRoute route, string parameterName, IDictionary<string, object> values, HttpRouteDirection routeDirection )
         {
+            if ( IsNullOrEmpty( parameterName ) )
+            {
+                return false;
+            }
+
             var value = default( string );
 
+            if ( values.TryGetValue( parameterName, out value ) )
+            {
+                request.SetRouteParameterName( parameterName );
+            }
+            else
+            {
+                return false;
+            }
+
             if ( routeDirection == UriGeneration )
             {
-                return !IsNullOrEmpty( parameterName ) && values.TryGetValue( parameterName, out value ) && !IsNullOrEmpty( value );
+                return !IsNullOrEmpty( value );
             }
 
             var requestedVersion = default( ApiVersion );
 
-            if ( !values.TryGetValue( parameterName, out value ) || !TryParse( value, out requestedVersion ) )
+            if ( TryParse( value, out requestedVersion ) )
             {
-                return false;
+                request.SetRequestedApiVersion( requestedVersion );
+                return true;
             }
 
-            request.SetRequestedApiVersion( requestedVersion );
-            return true;
+            return false;
         }
     }
-}
+}
diff --git a/src/Microsoft.AspNet.WebApi.Versioning/System.Web.Http/HttpRequestMessageExtensions.cs b/src/Microsoft.AspNet.WebApi.Versioning/System.Web.Http/HttpRequestMessageExtensions.cs
@@ -5,19 +5,22 @@
     using Diagnostics.Contracts;
     using Microsoft;
     using Microsoft.Web.Http;
+    using Microsoft.Web.Http.Routing;
     using Microsoft.Web.Http.Versioning;
     using Net;
     using Net.Http;
     using System;
-    using static Microsoft.Web.Http.ApiVersion;
     using static ComponentModel.EditorBrowsableState;
+    using static Microsoft.Web.Http.ApiVersion;
+    using static System.String;
 
     /// <summary>
     /// Provides extension methods for the <see cref="HttpRequestMessage"/> class.
     /// </summary>
     public static class HttpRequestMessageExtensions
     {
         private const string ApiVersionKey = "MS_" + nameof( ApiVersion );
+        private const string ApiVersionRouteParameterName = "MS_" + nameof( ApiVersionRouteConstraint ) + "_ParameterName";
 
         [SuppressMessage( "Microsoft.Reliability", "CA2000:Dispose objects before losing scope", Justification = "Handled by the caller." )]
         private static HttpResponseMessage CreateErrorResponse( this HttpRequestMessage request, HttpStatusCode statusCode, Func<bool, HttpError> errorCreator )
@@ -140,5 +143,33 @@ public static void SetRequestedApiVersion( this HttpRequestMessage request, ApiV
                 request.Properties[ApiVersionKey] = version;
             }
         }
+
+        internal static string GetRouteParameterNameAssignedByApiVersionRouteConstraint( this HttpRequestMessage request )
+        {
+            Contract.Requires( request != null );
+
+            var parameterName = default( string );
+
+            if ( request.Properties.TryGetValue( ApiVersionRouteParameterName, out parameterName ) )
+            {
+                return parameterName;
+            }
+
+            return null;
+        }
+
+        internal static void SetRouteParameterName( this HttpRequestMessage request, string parameterName )
+        {
+            Contract.Requires( request != null );
+
+            if ( IsNullOrEmpty( parameterName ) )
+            {
+                request.Properties.Remove( ApiVersionRouteParameterName );
+            }
+            else
+            {
+                request.Properties[ApiVersionRouteParameterName] = parameterName;
+            }
+        }
     }
 }
diff --git a/src/Microsoft.AspNet.WebApi.Versioning/Versioning/UrlSegmentApiVersionReader.cs b/src/Microsoft.AspNet.WebApi.Versioning/Versioning/UrlSegmentApiVersionReader.cs
@@ -0,0 +1,77 @@
+﻿namespace Microsoft.Web.Http.Versioning
+{
+    using Routing;
+    using System.Diagnostics.Contracts;
+    using System.Net.Http;
+    using System.Web.Http;
+    using System.Web.Http.Routing;
+    using static System.String;
+
+    /// <content>
+    /// Provides the implementation for ASP.NET Web API.
+    /// </content>
+    public partial class UrlSegmentApiVersionReader
+    {
+        /// <summary>
+        /// Reads the service API version value from a request.
+        /// </summary>
+        /// <param name="request">The <see cref="HttpRequestMessage">HTTP request</see> to read the API version from.</param>
+        /// <returns>The raw, unparsed service API version value read from the request or <c>null</c> if request does not contain an API version.</returns>
+        /// <exception cref="AmbiguousApiVersionException">Multiple, different API versions were requested.</exception>
+        public virtual string Read( HttpRequestMessage request )
+        {
+            Arg.NotNull( request, nameof( request ) );
+
+            var routeData = request.GetRouteData();
+
+            if ( routeData == null )
+            {
+                return null;
+            }
+
+            var key = request.GetRouteParameterNameAssignedByApiVersionRouteConstraint();
+            var subRouteData = routeData.GetSubRoutes() ?? new[] { routeData };
+            var value = default( object );
+
+            if ( IsNullOrEmpty( key ) )
+            {
+                foreach ( var subRouteDatum in subRouteData )
+                {
+                    key = GetRouteParameterNameFromConstraintNameInTemplate( subRouteDatum );
+
+                    if ( key != null && subRouteDatum.Values.TryGetValue( key, out value ) )
+                    {
+                        return value.ToString();
+                    }
+                }
+            }
+            else
+            {
+                foreach ( var subRouteDatum in subRouteData )
+                {
+                    if ( subRouteDatum.Values.TryGetValue( key, out value ) )
+                    {
+                        return value.ToString();
+                    }
+                }
+            }
+
+            return null;
+        }
+
+        static string GetRouteParameterNameFromConstraintNameInTemplate( IHttpRouteData routeData )
+        {
+            Contract.Requires( routeData != null );
+
+            foreach ( var constraint in routeData.Route.Constraints )
+            {
+                if ( constraint.Value is ApiVersionRouteConstraint )
+                {
+                    return constraint.Key;
+                }
+            }
+
+            return null;
+        }
+    }
+}
diff --git a/src/Microsoft.AspNetCore.Mvc.Versioning/HttpContextExtensions.cs b/src/Microsoft.AspNetCore.Mvc.Versioning/HttpContextExtensions.cs
@@ -1,12 +1,14 @@
 ﻿namespace Microsoft.AspNetCore.Mvc
 {
     using Http;
+    using Routing;
     using System;
     using System.ComponentModel;
     using System.Diagnostics.Contracts;
     using Versioning;
     using static ApiVersion;
     using static System.ComponentModel.EditorBrowsableState;
+    using static System.String;
 
     /// <summary>
     /// Provides extension methods for the <see cref="HttpContext"/> class.
@@ -15,6 +17,7 @@
     public static class HttpContextExtensions
     {
         private const string ApiVersionKey = "MS_" + nameof( ApiVersion );
+        private const string ApiVersionRouteParameterName = "MS_" + nameof( ApiVersionRouteConstraint ) + "_ParameterName";
 
         /// <summary>
         /// Gets the current raw, unparsed service API version requested.
@@ -76,5 +79,33 @@ internal static void SetRequestedApiVersion( this HttpContext context, ApiVersio
                 context.Items[ApiVersionKey] = version;
             }
         }
+
+        internal static string GetRouteParameterNameAssignedByApiVersionRouteConstraint( this HttpContext context )
+        {
+            Contract.Requires( context != null );
+
+            var parameterName = default( string );
+
+            if ( context.Items.TryGetValue( ApiVersionRouteParameterName, out parameterName ) )
+            {
+                return parameterName;
+            }
+
+            return null;
+        }
+
+        internal static void SetRouteParameterName( this HttpContext context, string parameterName )
+        {
+            Contract.Requires( context != null );
+
+            if ( IsNullOrEmpty( parameterName ) )
+            {
+                context.Items.Remove( ApiVersionRouteParameterName );
+            }
+            else
+            {
+                context.Items[ApiVersionRouteParameterName] = parameterName;
+            }
+        }
     }
-}
+}
diff --git a/src/Microsoft.AspNetCore.Mvc.Versioning/Routing/ApiVersionRouteConstraint.cs b/src/Microsoft.AspNetCore.Mvc.Versioning/Routing/ApiVersionRouteConstraint.cs
@@ -24,22 +24,36 @@ public sealed class ApiVersionRouteConstraint : IRouteConstraint
         /// <returns>True if the route constraint is matched; otherwise, false.</returns>
         public bool Match( HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values, RouteDirection routeDirection )
         {
+            if ( IsNullOrEmpty( routeKey ) )
+            {
+                return false;
+            }
+
             var value = default( string );
 
+            if ( values.TryGetValue( routeKey, out value ) )
+            {
+                httpContext.SetRouteParameterName( routeKey );
+            }
+            else
+            {
+                return false;
+            }
+
             if ( routeDirection == UrlGeneration )
             {
-                return !IsNullOrEmpty( routeKey ) && values.TryGetValue( routeKey, out value ) && !IsNullOrEmpty( value );
+                return !IsNullOrEmpty( value );
             }
 
             var requestedVersion = default( ApiVersion );
 
-            if ( !values.TryGetValue( routeKey, out value ) || !TryParse( value, out requestedVersion ) )
+            if ( TryParse( value, out requestedVersion ) )
             {
-                return false;
+                httpContext.SetRequestedApiVersion( requestedVersion );
+                return true;
             }
 
-            httpContext.SetRequestedApiVersion( requestedVersion );
-            return true;
+            return false;
         }
     }
 }
diff --git a/src/Microsoft.AspNetCore.Mvc.Versioning/Versioning/UrlSegmentApiVersionReader.cs b/src/Microsoft.AspNetCore.Mvc.Versioning/Versioning/UrlSegmentApiVersionReader.cs
@@ -1,41 +1,35 @@
 ﻿namespace Microsoft.AspNetCore.Mvc.Versioning
 {
+    using AspNetCore.Routing;
     using Http;
     using System;
-    using System.Collections.Generic;
-    using System.Linq;
     using static System.String;
 
     /// <content>
     /// Provides the implementation for ASP.NET Core.
     /// </content>
     [CLSCompliant( false )]
-    public partial class QueryStringOrHeaderApiVersionReader
+    public partial class UrlSegmentApiVersionReader
     {
         /// <summary>
         /// Reads the service API version value from a request.
         /// </summary>
         /// <param name="request">The <see cref="HttpRequest">HTTP request</see> to read the API version from.</param>
         /// <returns>The raw, unparsed service API version value read from the request or <c>null</c> if request does not contain an API version.</returns>
         /// <exception cref="AmbiguousApiVersionException">Multiple, different API versions were requested.</exception>
-        public override string Read( HttpRequest request )
+        public virtual string Read( HttpRequest request )
         {
-            var version = base.Read( request );
-            var versions = new HashSet<string>( StringComparer.OrdinalIgnoreCase );
+            Arg.NotNull( request, nameof( request ) );
 
-            if ( !IsNullOrEmpty( version ) )
-            {
-                versions.Add( version );
-            }
-
-            version = ReadFromHeader( request, HeaderNames );
+            var context = request.HttpContext;
+            var key = context.GetRouteParameterNameAssignedByApiVersionRouteConstraint();
 
-            if ( !IsNullOrEmpty( version ) )
+            if ( IsNullOrEmpty( key ) )
             {
-                versions.Add( version );
+                return null;
             }
 
-            return versions.EnsureZeroOrOneApiVersions();
+            return context.GetRouteValue( key )?.ToString();
         }
     }
-}
+}
diff --git a/test/Microsoft.AspNet.WebApi.Versioning.Tests/Versioning/UrlSegmentApiVersionReaderTest.cs b/test/Microsoft.AspNet.WebApi.Versioning.Tests/Versioning/UrlSegmentApiVersionReaderTest.cs
diff --git a/test/Microsoft.AspNetCore.Mvc.Versioning.Tests/Routing/ApiVersionRouteConstraintTest.cs b/test/Microsoft.AspNetCore.Mvc.Versioning.Tests/Routing/ApiVersionRouteConstraintTest.cs
diff --git a/test/Microsoft.AspNetCore.Mvc.Versioning.Tests/Versioning/UrlSegmentApiVersionReaderTest.cs b/test/Microsoft.AspNetCore.Mvc.Versioning.Tests/Versioning/UrlSegmentApiVersionReaderTest.cs

Original file line number	Diff line number	Diff line change
`@@ -24,22 +24,36 @@ public sealed class ApiVersionRouteConstraint : IRouteConstraint`
`24`	`24`	`/// <returns>True if the route constraint is matched; otherwise, false.</returns>`
`25`	`25`	`public bool Match( HttpContext httpContext, IRouter route, string routeKey, RouteValueDictionary values, RouteDirection routeDirection )`
`26`	`26`	`{`
	`27`	`+ if ( IsNullOrEmpty( routeKey ) )`
	`28`	`+ {`
	`29`	`+ return false;`
	`30`	`+ }`
	`31`	`+`
`27`	`32`	`var value = default( string );`
`28`	`33`
	`34`	`+ if ( values.TryGetValue( routeKey, out value ) )`
	`35`	`+ {`
	`36`	`+ httpContext.SetRouteParameterName( routeKey );`
	`37`	`+ }`
	`38`	`+ else`
	`39`	`+ {`
	`40`	`+ return false;`
	`41`	`+ }`
	`42`	`+`
`29`	`43`	`if ( routeDirection == UrlGeneration )`
`30`	`44`	`{`
`31`		`- return !IsNullOrEmpty( routeKey ) && values.TryGetValue( routeKey, out value ) && !IsNullOrEmpty( value );`
	`45`	`+ return !IsNullOrEmpty( value );`
`32`	`46`	`}`
`33`	`47`
`34`	`48`	`var requestedVersion = default( ApiVersion );`
`35`	`49`
`36`		`- if ( !values.TryGetValue( routeKey, out value ) \|\| !TryParse( value, out requestedVersion ) )`
	`50`	`+ if ( TryParse( value, out requestedVersion ) )`
`37`	`51`	`{`
`38`		`- return false;`
	`52`	`+ httpContext.SetRequestedApiVersion( requestedVersion );`
	`53`	`+ return true;`
`39`	`54`	`}`
`40`	`55`
`41`		`- httpContext.SetRequestedApiVersion( requestedVersion );`
`42`		`- return true;`
	`56`	`+ return false;`
`43`	`57`	`}`
`44`	`58`	`}`
`45`	`59`	`}`