Merge branch 'dev-v7.7' of https://github.com/umbraco/Umbraco-CMS into dev-v7.7

src/Umbraco.Core/Deploy/IUniqueIdentifyingServiceConnector.cs

@@ -0,0 +1,25 @@
+namespace Umbraco.Core.Deploy
+{
+    /// <summary>
+    /// Provides a method to retrieve an artifact's unique identifier.
+    /// </summary>
+    /// <remarks>
+    /// Artifacts are uniquely identified by their <see cref="Udi"/>, however they represent
+    /// elements in Umbraco that may be uniquely identified by another value. For example,
+    /// a content type is uniquely identified by its alias. If someone creates a new content
+    /// type, and tries to deploy it to a remote environment where a content type with the
+    /// same alias already exists, both content types end up having different <see cref="Udi"/>
+    /// but the same alias. By default, Deploy would fail and throw when trying to save the
+    /// new content type (duplicate alias). However, if the connector also implements this
+    /// interface, the situation can be detected beforehand and reported in a nicer way.
+    /// </remarks>
+    public interface IUniqueIdentifyingServiceConnector
+    {
+        /// <summary>
+        /// Gets the unique identifier of the specified artifact.
+        /// </summary>
+        /// <param name="artifact">The artifact.</param>
+        /// <returns>The unique identifier.</returns>
+        string GetUniqueIdentifier(IArtifact artifact);
+    }
+}

src/Umbraco.Core/Umbraco.Core.csproj

@@ -335,6 +335,7 @@
     <Compile Include="DateTimeExtensions.cs" />
     <Compile Include="DecimalExtensions.cs" />
     <Compile Include="DelegateExtensions.cs" />
+    <Compile Include="Deploy\IUniqueIdentifyingServiceConnector.cs" />
     <Compile Include="Diagnostics\MiniDump.cs" />
     <Compile Include="Deploy\ArtifactBase.cs" />
     <Compile Include="Deploy\ArtifactDependency.cs" />