Introduced new ReferentialIntegrityException

JeremyCaney · JeremyCaney · commit 29c904a53433 · 2020-09-08T14:05:54.000-07:00
The new `ReferentialIntegrityException` derives from `TopicRepositoryException`, and fires when an operation would introduce a referential integrity error in the underlying database.

Currently, this is expected when a topic is deleted which other topics derive from. As such, an optional overload accepts a `Topic` and completes the message based on that `Topic` as well as its `DerivedTopic`.
diff --git a/OnTopic/Repositories/ReferentialIntegrityException.cs b/OnTopic/Repositories/ReferentialIntegrityException.cs
@@ -0,0 +1,85 @@
+﻿/*==============================================================================================================================
+| Author        Ignia, LLC
+| Client        Ignia, LLC
+| Project       Topics Library
+\=============================================================================================================================*/
+using System;
+using System.Runtime.Serialization;
+using OnTopic.Internal.Diagnostics;
+
+namespace OnTopic.Repositories {
+
+  /*============================================================================================================================
+  | CLASS: REFERENTIAL INTEGRITY EXCEPTION
+  \---------------------------------------------------------------------------------------------------------------------------*/
+  /// <summary>
+  ///   The <see cref="ReferentialIntegrityException"/> will be thrown when an operation violates the referential integrity of
+  ///   the underlying persistence layer.
+  /// </summary>
+  /// <remarks>
+  ///   Generally, the <see cref="ReferentialIntegrityException"/> will occur when a <see cref="Topic"/> is being
+  ///   deleted, but the topic or one of its descendents is the <see cref="Topic.DerivedTopic"/> of another <see cref="Topic"/>.
+  ///   In that case, deleting the topic will violate the referential integrity of the target topic.
+  /// </remarks>
+  [Serializable]
+  public class ReferentialIntegrityException: TopicRepositoryException {
+
+    /*==========================================================================================================================
+    | CONSTRUCTOR: REFERENTIAL INTEGRITY EXCEPTION
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="ReferentialIntegrityException" /> instance.
+    /// </summary>
+    public ReferentialIntegrityException() : base() { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="ReferentialIntegrityException" /> instance based on the source <see cref=
+    ///   "Topic"/>.
+    /// </summary>
+    /// <param name="sourceTopic">The source <see cref="Topic"/> which triggered the exception.</param>
+    public ReferentialIntegrityException(Topic sourceTopic):
+      base(
+        $"The operation on the topic '{sourceTopic?.DerivedTopic?.GetUniqueKey()}' would introduce a referential integrity " +
+        $"violation in the underlying persistence layer; the topic '{sourceTopic?.GetUniqueKey()}' depends upon it."
+      ) { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="ReferentialIntegrityException" /> instance based on the source <see cref=
+    ///   "Topic"/>.
+    /// </summary>
+    /// <param name="sourceTopic">The source <see cref="Topic"/> which triggered the exception.</param>
+    /// <param name="innerException">The reference to the original, underlying exception.</param>
+    public ReferentialIntegrityException(Topic sourceTopic, Exception innerException):
+      base(
+        $"The operation on the topic '{sourceTopic?.DerivedTopic?.GetUniqueKey()}' would introduce a referential integrity " +
+        $"violation in the underlying persistence layer; the topic '{sourceTopic?.GetUniqueKey()}' depends upon it.",
+        innerException
+      ) { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="ReferentialIntegrityException" /> instance based on a <paramref name=
+    ///   "message"/>.
+    /// </summary>
+    /// <param name="message">The error message to associate with the exception.</param>
+    public ReferentialIntegrityException(string message) : base(message) { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="ReferentialIntegrityException" /> instance based on a <paramref name=
+    ///   "message"/>.
+    /// </summary>
+    /// <param name="message">The error message to associate with the exception.</param>
+    /// <param name="innerException">The reference to the original, underlying exception.</param>
+    public ReferentialIntegrityException(string message, Exception innerException) : base(message, innerException) { }
+
+    /// <summary>
+    ///   Instantiates a new <see cref="ReferentialIntegrityException"/> instance for serialization.
+    /// </summary>
+    /// <param name="info">A <see cref="SerializationInfo"/> instance with details about the serialization requirements.</param>
+    /// <param name="context">A <see cref="StreamingContext"/> instance with details about the request context.</param>
+    /// <returns>A new <see cref="InvalidKeyException"/> instance.</returns>
+    protected ReferentialIntegrityException(SerializationInfo info, StreamingContext context) : base(info, context) {
+      Contract.Requires(info);
+    }
+
+  } //Class
+} //Namespace
