IResourceId and ResourceId.

src/ResourceManager/Common/Commands.Common.Strategies/Commands.Common.Strategies.csproj

@@ -60,7 +60,9 @@
     <Compile Include="INestedResourceConfig.cs" />
     <Compile Include="INestedResourceConfigVisitor.cs" />
     <Compile Include="INestedResourceStrategy.cs" />
+    <Compile Include="IResourceId.cs" />
     <Compile Include="Property.cs" />
+    <Compile Include="ResourceId.cs" />
     <Compile Include="ResourceType.cs" />
     <Compile Include="SdkEngine.cs" />
     <Compile Include="IEngine.cs" />

src/ResourceManager/Common/Commands.Common.Strategies/EntityConfigExtensions.cs

@@ -19,8 +19,6 @@ namespace Microsoft.Azure.Commands.Common.Strategies
 {
     public static class EntityConfigExtensions
     {
-        public const string Providers = "providers";
-
         public static string IdToString(this IEnumerable<string> id)
             => "/" + string.Join("/", id);
 
@@ -34,14 +32,14 @@ public static IEnumerable<string> GetIdFromSubscription(this IEntityConfig confi
         {
             var resourceGroupId = new[] 
             {
-                ResourceType.ResourceGroups, config.GetResourceGroupName()
+                ResourceId.ResourceGroups, config.GetResourceGroupName()
             };
             return config.ResourceGroup == null
                 ? resourceGroupId
                 : resourceGroupId.Concat(config.GetProvidersId());
         }
 
         internal static IEnumerable<string> GetProvidersId(this IEntityConfig config)
-            => new[] { Providers }.Concat(config.GetIdFromResourceGroup());
+            => new[] { ResourceId.Providers }.Concat(config.GetIdFromResourceGroup());
     }
 }

src/ResourceManager/Common/Commands.Common.Strategies/IResourceId.cs

@@ -0,0 +1,24 @@
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+namespace Microsoft.Azure.Commands.Common.Strategies
+{
+    public interface IResourceId
+    {
+        string SubscriptionId { get; }
+        string ResourceGroupName { get; }
+        ResourceType ResourceType { get; }
+        string Name { get; }
+    }
+}

src/ResourceManager/Common/Commands.Common.Strategies/ResourceId.cs

@@ -0,0 +1,79 @@
+// ----------------------------------------------------------------------------------
+//
+// Copyright Microsoft Corporation
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ----------------------------------------------------------------------------------
+
+namespace Microsoft.Azure.Commands.Common.Strategies
+{
+    public static class ResourceId
+    {
+        public const string Subscriptions = "subscriptions";
+        public const string ResourceGroups = "resourceGroups";
+        public const string Providers = "providers";
+
+        /// <summary>
+        /// Returns 'null' if the given id is not parsable.
+        /// </summary>
+        /// <param name="id"></param>
+        /// <returns></returns>
+        public static IResourceId TryParse(string id)
+        {
+            const int EmptyI = 0;
+            const int SubscriptionsI = 1;
+            const int SubscriptionIdI = 2;
+            const int ResourceGroupsI = 3;
+            const int ResourceGroupNameI = 4;
+            const int ProvidersI = 5;
+            const int NamespaceI = 6;
+            const int ProviderI = 7;
+            const int NameI = 8;
+
+            var parts = id.Split('/');
+            return parts.Length == 9
+                    && parts[EmptyI] == string.Empty
+                    && parts[SubscriptionsI] == Subscriptions
+                    && parts[ResourceGroupsI] == ResourceGroups
+                    && parts[ProvidersI] == Providers
+                ? new Implementation(
+                    subscriptionId: parts[SubscriptionIdI],
+                    resourceGroupName: parts[ResourceGroupNameI],
+                    resourceType: new ResourceType(
+                        namespace_: parts[NamespaceI],
+                        provider: parts[ProviderI]),
+                    name: parts[NameI])
+                : null;
+        }
+
+        sealed class Implementation : IResourceId
+        {
+            public string Name { get; }
+
+            public string ResourceGroupName { get; }
+
+            public ResourceType ResourceType { get; }
+
+            public string SubscriptionId { get; }
+
+            public Implementation(
+                string subscriptionId,
+                string resourceGroupName,
+                ResourceType resourceType,
+                string name)
+            {
+                SubscriptionId = subscriptionId;
+                ResourceGroupName = resourceGroupName;
+                ResourceType = resourceType;
+                Name = name;
+            }
+        }
+    }
+}

src/ResourceManager/Common/Commands.Common.Strategies/ResourceType.cs

@@ -15,11 +15,9 @@
 namespace Microsoft.Azure.Commands.Common.Strategies
 {
     public sealed class ResourceType
-    {
-        public const string ResourceGroups = "resourceGroups";
-
+    {       
         public static ResourceType ResourceGroup { get; }
-            = new ResourceType(null, ResourceGroups);
+            = new ResourceType(null, ResourceId.ResourceGroups);
 
         /// <summary>
         /// A resource type namespace, for example 'Microsoft.Network'.

src/ResourceManager/Common/Commands.Common.Strategies/SdkEngine.cs

@@ -20,9 +20,7 @@ namespace Microsoft.Azure.Commands.Common.Strategies
     /// Engine for REST API calls using Azure SDK.
     /// </summary>
     public sealed class SdkEngine : IEngine
-    {
-        public const string Subscriptions = "subscriptions";
-
+    {        
         string _SubscriptionId { get; }
 
         public SdkEngine(string subscriptionId)
@@ -31,7 +29,7 @@ public SdkEngine(string subscriptionId)
         }
 
         public string GetId(IEntityConfig config)
-            => new[] { Subscriptions, _SubscriptionId } 
+            => new[] { ResourceId.Subscriptions, _SubscriptionId } 
                 .Concat(config.GetIdFromSubscription()) 
                 .IdToString();
     }

src/ResourceManager/Compute/Commands.Compute/Strategies/ComputeRp/ImageEx.cs

@@ -86,43 +86,22 @@ public static async Task<ImageAndOsType> UpdateImageAndOsTypeAsync(
             }
             else if (imageName.Contains("/"))
             {
-                var imageArray = imageName.Split('/');
-                if (imageArray.Length != 9)
+                var resourceId = ResourceId.TryParse(imageName);
+                if (resourceId == null
+                    || resourceId.ResourceType.Namespace != ComputeStrategy.Namespace
+                    || resourceId.ResourceType.Provider != "images")
                 {
                     throw new ArgumentException(string.Format(Resources.ComputeInvalidImageName, imageName));
                 }
-                // has to be ""
-                var empty = imageArray[0];
-                // has to be "subscriptions"
-                var subscriptions = imageArray[1];
-                var subscriptionId = imageArray[2];
-                // has to be "resourceGroups"
-                var resourceGroups = imageArray[3];
-                var imageResourceGroupName = imageArray[4];
-                // has to be "providers"
-                var providers = imageArray[5];
-                // has to be "Microsoft."
-                var providerNamespace = imageArray[6];
-                // has to be "image" 
-                var provider = imageArray[7];
-                var resourceName = imageArray[8];
 
-                if (empty != string.Empty
-                    || subscriptions != SdkEngine.Subscriptions
-                    || resourceGroups != ResourceType.ResourceGroups
-                    || providers != EntityConfigExtensions.Providers
-                    || providerNamespace != ComputeStrategy.Namespace
-                    || provider != "images")
-                {
-                    throw new ArgumentException(string.Format(Resources.ComputeInvalidImageName, imageName));
-                }
-
-                if (compute.SubscriptionId != subscriptionId)
+                if (compute.SubscriptionId != resourceId.SubscriptionId)
                 {
                     throw new ArgumentException(Resources.ComputeMismatchSubscription);
                 }
 
-                var localImage = await compute.Images.GetAsync(imageResourceGroupName, resourceName);
+                var localImage = await compute.Images.GetAsync(
+                    resourceGroupName: resourceId.ResourceGroupName,
+                    imageName: resourceId.Name);
 
                 return new ImageAndOsType(
                     localImage.StorageProfile.OsDisk.OsType,