Added If object extension.

framework/src/Volo.Abp.Core/System/AbpObjectExtensions.cs

@@ -42,5 +42,50 @@ namespace System
         {
             return list.Contains(item);
         }
+        
+        /// <summary>
+        /// Can be used to conditionally perform a function
+        /// on an object and return the modified or the original object.
+        /// It is useful for chained calls.
+        /// </summary>
+        /// <param name="obj">An object</param>
+        /// <param name="condition">A condition</param>
+        /// <param name="func">A function that is executed only if the condition is <code>true</code></param>
+        /// <typeparam name="T">Type of the object</typeparam>
+        /// <returns>
+        /// Returns the modified object (by the <paramref name="func"/> if the <paramref name="condition"/> is <code>true</code>)
+        /// or the original object if the <paramref name="condition"/> is <code>false</code>
+        /// </returns>
+        public static T If<T>(this T obj, bool condition, Func<T, T> func)
+        {
+            if (condition)
+            {
+                return func(obj);
+            }
+
+            return obj;
+        }
+        
+        /// <summary>
+        /// Can be used to conditionally perform an action
+        /// on an object and return the original object.
+        /// It is useful for chained calls on the object.
+        /// </summary>
+        /// <param name="obj">An object</param>
+        /// <param name="condition">A condition</param>
+        /// <param name="action">An action that is executed only if the condition is <code>true</code></param>
+        /// <typeparam name="T">Type of the object</typeparam>
+        /// <returns>
+        /// Returns the original object.
+        /// </returns>
+        public static T If<T>(this T obj, bool condition, Action<T> action)
+        {
+            if (condition)
+            {
+                action(obj);
+            }
+
+            return obj;
+        }
     }
 }

framework/test/Volo.Abp.Core.Tests/System/ObjectExtension_Test.cs

@@ -52,5 +52,22 @@ namespace System
             str = null;
             str.IsIn("a", "b", "c").ShouldBe(false);
         }
+
+        [Fact]
+        public void If_Tests()
+        {
+            var value = 0;
+            
+            value = value.If(true, v => v + 1);
+            value.ShouldBe(1);
+            
+            value = value.If(false, v => v + 1);
+            value.ShouldBe(1);
+
+            value = value
+                .If(true, v => v + 3)
+                .If(false, v => v + 5);
+            value.ShouldBe(4);
+        }
     }
 }