Added extension methods for ISettingsStorageHelper

Author: shweaver-MSFT

Microsoft.Toolkit/Extensions/ISettingsStorageHelperExtensions.cs

@@ -0,0 +1,88 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Microsoft.Toolkit.Helpers;
+
+namespace Microsoft.Toolkit.Extensions
+{
+    /// <summary>
+    /// Helpers methods for working with <see cref="ISettingsStorageHelper{TKey}"/> implementations.
+    /// </summary>
+    public static class ISettingsStorageHelperExtensions
+    {
+        /// <summary>
+        /// Attempts to read the provided key and return the value.
+        /// If the key is not found, the fallback value will be used instead.
+        /// </summary>
+        /// <typeparam name="TKey">The type of key used to lookup the object.</typeparam>
+        /// <typeparam name="TValue">The type of object value expected.</typeparam>
+        /// <param name="storageHelper">The storage helper instance fo read from.</param>
+        /// <param name="key">The key of the target object.</param>
+        /// <param name="fallback">An alternative value returned if the read fails.</param>
+        /// <returns>The value of the target object, or the fallback value.</returns>
+        public static TValue? GetValueOrDefault<TKey, TValue>(this ISettingsStorageHelper<TKey> storageHelper, TKey key, TValue? fallback = default)
+            where TKey : notnull
+        {
+            try
+            {
+                return storageHelper.Read<TValue>(key);
+            }
+            catch (KeyNotFoundException)
+            {
+                return fallback;
+            }
+        }
+
+        /// <summary>
+        /// Attempts to perform read the provided key and returns a boolean indicator of success.
+        /// If the key is not found, the fallback value will be used instead.
+        /// </summary>
+        /// <typeparam name="TKey">The type of key used to lookup the object.</typeparam>
+        /// <typeparam name="TValue">The type of object value expected.</typeparam>
+        /// <param name="storageHelper">The storage helper instance to read from.</param>
+        /// <param name="key">The key of the target object.</param>
+        /// <param name="value">The value of the target object, or the fallback value.</param>
+        /// <param name="fallback">An alternate value returned if the read fails.</param>
+        /// <returns>A boolean indicator of success.</returns>
+        public static bool TryRead<TKey, TValue>(this ISettingsStorageHelper<TKey> storageHelper, TKey key, out TValue? value, TValue? fallback = default)
+            where TKey : notnull
+        {
+            try
+            {
+                value = storageHelper.Read<TValue>(key);
+                return true;
+            }
+            catch (KeyNotFoundException)
+            {
+                value = fallback;
+                return false;
+            }
+        }
+
+        /// <summary>
+        /// Attempts to remove an object by key and returns a boolean indicator of success.
+        /// If the key is not found, the method will return false.
+        /// </summary>
+        /// <typeparam name="TKey">The type of key used to lookup the object.</typeparam>
+        /// <param name="storageHelper">The storage helper instance to delete from.</param>
+        /// <param name="key">The key of the target object.</param>
+        /// <returns>A boolean indicator of success.</returns>
+        public static bool TryDelete<TKey>(this ISettingsStorageHelper<TKey> storageHelper, TKey key)
+            where TKey : notnull
+        {
+            try
+            {
+                storageHelper.Delete(key);
+                return true;
+            }
+            catch (KeyNotFoundException)
+            {
+                return false;
+            }
+        }
+    }
+}