Improved setting system.

src/Volo.Abp.Session/Volo/Abp/Session/UserSettingValueProvider.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using Volo.Abp.Settings;
 
 namespace Volo.Abp.Session
@@ -34,5 +33,15 @@ namespace Volo.Abp.Session
 
             return await SettingStore.GetOrNullAsync(setting.Name, EntityType, entityId);
         }
+
+        public override Task SetAsync(SettingDefinition setting, string value, string entityId)
+        {
+            return SettingStore.SetAsync(setting.Name, value, EntityType, entityId);
+        }
+
+        public override Task ClearAsync(SettingDefinition setting, string entityId)
+        {
+            return SettingStore.DeleteAsync(setting.Name, EntityType, entityId);
+        }
     }
 }

src/Volo.Abp.Settings.Domain/Volo/Abp/Settings/SettingStore.cs

@@ -38,5 +38,14 @@ namespace Volo.Abp.Settings
             var setting = await _settingRepository.GetListAsync(entityType, entityId);
             return setting.Select(s => new SettingValue(s.Name, s.Value)).ToList();
         }
+
+        public async Task DeleteAsync(string name, string entityType, string entityId)
+        {
+            var setting = await _settingRepository.FindAsync(name, entityType, entityId);
+            if (setting != null)
+            {
+                await _settingRepository.DeleteAsync(setting);
+            }
+        }
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/DefaultStoreSettingValueProvider.cs

@@ -15,5 +15,15 @@ namespace Volo.Abp.Settings
         {
             return SettingStore.GetOrNullAsync(setting.Name, null, null);
         }
+
+        public override Task SetAsync(SettingDefinition setting, string value, string entityId)
+        {
+            return SettingStore.SetAsync(setting.Name, value, null, null);
+        }
+
+        public override Task ClearAsync(SettingDefinition setting, string entityId)
+        {
+            return SettingStore.DeleteAsync(setting.Name, null, null);
+        }
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/DefaultValueSettingValueProvider.cs

@@ -16,5 +16,17 @@ namespace Volo.Abp.Settings
         {
             return Task.FromResult(setting.DefaultValue);
         }
+
+        public override Task SetAsync(SettingDefinition setting, string value, string entityId)
+        {
+            setting.DefaultValue = value;
+            return Task.CompletedTask;
+        }
+
+        public override Task ClearAsync(SettingDefinition setting, string entityId)
+        {
+            setting.DefaultValue = null;
+            return Task.CompletedTask;
+        }
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/ISettingStore.cs

@@ -11,5 +11,7 @@ namespace Volo.Abp.Settings
         Task SetAsync([NotNull] string name, [NotNull] string value, [CanBeNull] string entityType, [CanBeNull] string entityId);
 
         Task<List<SettingValue>> GetListAsync([CanBeNull] string entityType, [CanBeNull] string entityId);
+
+        Task DeleteAsync([NotNull] string name, [CanBeNull]string entityType, [CanBeNull]string entityId);
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/ISettingValueProvider.cs

@@ -8,5 +8,9 @@ namespace Volo.Abp.Settings
         string EntityType { get; }
 
         Task<string> GetOrNullAsync([NotNull] SettingDefinition setting, [CanBeNull] string entityId);
+
+        Task SetAsync([NotNull] SettingDefinition setting, [NotNull] string value, [CanBeNull] string entityId);
+
+        Task ClearAsync([NotNull] SettingDefinition setting, [CanBeNull] string entityId);
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/NullSettingStore.cs

@@ -0,0 +1,29 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Volo.Abp.DependencyInjection;
+
+namespace Volo.Abp.Settings
+{
+    public class NullSettingStore : ISettingStore, ISingletonDependency
+    {
+        public Task<string> GetOrNullAsync(string name, string entityType, string entityId)
+        {
+            return Task.FromResult((string) null);
+        }
+
+        public Task SetAsync(string name, string value, string entityType, string entityId)
+        {
+            return Task.CompletedTask;
+        }
+
+        public Task<List<SettingValue>> GetListAsync(string entityType, string entityId)
+        {
+            return Task.FromResult(new List<SettingValue>());
+        }
+
+        public Task DeleteAsync(string name, string entityType, string entityId)
+        {
+            return Task.CompletedTask;
+        }
+    }
+}

src/Volo.Abp.Settings/Volo/Abp/Settings/SettingManager.cs

@@ -38,34 +38,31 @@ namespace Volo.Abp.Settings
             );
         }
 
-        public virtual async Task<string> GetOrNullAsync(string name)
+        public virtual Task<string> GetOrNullAsync(string name)
         {
             Check.NotNull(name, nameof(name));
 
-            var setting = SettingDefinitionManager.Get(name);
-            var contributors = Enumerable.Reverse(Providers.Value);
-
-            foreach (var contributor in contributors)
-            {
-                var value = await contributor.GetOrNullAsync(setting, null);
-                if (value != null)
-                {
-                    return value;
-                }
-            }
-
-            return null;
+            return GetOrNullInternalAsync(name, null, null);
         }
 
-        public virtual async Task<string> GetOrNullAsync(string name, string entityType, string entityId, bool fallback = true)
+        public virtual Task<string> GetOrNullAsync(string name, string entityType, string entityId, bool fallback = true)
         {
             Check.NotNull(name, nameof(name));
             Check.NotNull(entityType, nameof(entityType));
+            
+            return GetOrNullInternalAsync(name, entityType, entityId, fallback);
+        }
 
+        public virtual async Task<string> GetOrNullInternalAsync(string name, string entityType, string entityId, bool fallback = true)
+        {
             var setting = SettingDefinitionManager.Get(name);
             var providers = Enumerable
-                .Reverse(Providers.Value)
-                .SkipWhile(c => c.EntityType != entityType);
+                .Reverse(Providers.Value);
+
+            if (entityType != null)
+            {
+                providers = providers.SkipWhile(c => c.EntityType != entityType);
+            }
 
             if (!fallback)
             {
@@ -137,12 +134,56 @@ namespace Volo.Abp.Settings
 
         public virtual Task SetAsync(string name, string value, bool forceToSet = false)
         {
-            throw new System.NotImplementedException();
+            Check.NotNull(name, nameof(name));
+
+            return SetInternalAsync(name, value, null, null, forceToSet);
         }
 
         public virtual Task SetAsync(string name, string value, string entityType, string entityId, bool forceToSet = false)
         {
-            throw new System.NotImplementedException();
+            Check.NotNull(name, nameof(name));
+            Check.NotNull(entityType, nameof(entityType));
+
+            return SetInternalAsync(name, value, entityType, entityId, forceToSet);
+        }
+
+        protected virtual async Task SetInternalAsync(string name, string value, string entityType, string entityId, bool forceToSet = false)
+        {
+            var setting = SettingDefinitionManager.Get(name);
+
+            if (!forceToSet)
+            {
+                var currentValue = await GetOrNullInternalAsync(name, entityType, entityId);
+                if (currentValue == value)
+                {
+                    return;
+                }
+            }
+
+            var providers = Enumerable
+                .Reverse(Providers.Value)
+                .SkipWhile(p => p.EntityType != entityType)
+                .ToList();
+
+            if (!providers.Any())
+            {
+                return;
+            }
+
+            if (value == null)
+            {
+                foreach (var provider in providers)
+                {
+                    await provider.ClearAsync(setting, entityId);
+                }
+            }
+            else
+            {
+                foreach (var provider in providers)
+                {
+                    await provider.SetAsync(setting, value, entityId);
+                }
+            }
         }
     }
 }

src/Volo.Abp.Settings/Volo/Abp/Settings/SettingValueProvider.cs

@@ -15,5 +15,9 @@ namespace Volo.Abp.Settings
         }
 
         public abstract Task<string> GetOrNullAsync(SettingDefinition setting, string entityId);
+
+        public abstract Task SetAsync(SettingDefinition setting, string value, string entityId);
+
+        public abstract Task ClearAsync(SettingDefinition setting, string entityId);
     }
 }

test/Volo.Abp.Settings.Tests/Volo/Abp/Settings/SettingManager_Basic_Tests.cs

@@ -4,11 +4,11 @@ using Xunit;
 
 namespace Volo.Abp.Settings
 {
-    public class SettingManager_Tests : AbpSettingsTestBase
+    public class SettingManager_Basic_Tests : AbpSettingsTestBase
     {
         private readonly ISettingManager _settingManager;
 
-        public SettingManager_Tests()
+        public SettingManager_Basic_Tests()
         {
             _settingManager = GetRequiredService<ISettingManager>();
         }
@@ -42,5 +42,14 @@ namespace Volo.Abp.Settings
             settingValues.ShouldContain(sv => sv.Name == "MySetting2" && sv.Value == "default-store-value");
             settingValues.ShouldContain(sv => sv.Name == "SettingNotSetInStore" && sv.Value == "default-value");
         }
+
+        [Fact]
+        public async Task Should_Set_Value()
+        {
+            await _settingManager.SetAsync("MySetting1", "43");
+
+            (await _settingManager.GetOrNullAsync("MySetting1")).ShouldBe("43");
+            //TODO: Also check database!
+        }
     }
 }

test/Volo.Abp.Settings.Tests/Volo/Abp/Settings/SettingManager_User_Tests.cs

@@ -8,13 +8,13 @@ using Xunit;
 
 namespace Volo.Abp.Settings
 {
-    public class SettingManager_User_GetValue_Tests: AbpSettingsTestBase
+    public class SettingManager_User_Tests: AbpSettingsTestBase
     {
         private Guid _currentUserId;
 
         private readonly ISettingManager _settingManager;
 
-        public SettingManager_User_GetValue_Tests()
+        public SettingManager_User_Tests()
         {
             _settingManager = GetRequiredService<ISettingManager>();
         }