Deferred conversion.

src/Squidex.Domain.Apps.Entities/Contents/ContentQueryService.cs

@@ -8,7 +8,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Security.Claims;
 using System.Threading.Tasks;
 using Microsoft.Extensions.Options;
 using Microsoft.OData;
@@ -23,9 +22,7 @@ using Squidex.Infrastructure.Log;
 using Squidex.Infrastructure.Queries;
 using Squidex.Infrastructure.Queries.OData;
 using Squidex.Infrastructure.Reflection;
-using Squidex.Infrastructure.Security;
 using Squidex.Shared;
-using Squidex.Shared.Identity;
 
 #pragma warning disable RECS0147
 

src/Squidex.Web/ApiPermissionAttribute.cs

@@ -12,7 +12,6 @@ using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Squidex.Infrastructure.Security;
 using Squidex.Infrastructure.Tasks;
-using Squidex.Shared.Identity;
 
 namespace Squidex.Web
 {

src/Squidex.Web/Deferred.cs

@@ -0,0 +1,42 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Threading.Tasks;
+using Squidex.Infrastructure;
+
+namespace Squidex.Web
+{
+    public struct Deferred
+    {
+        private readonly Lazy<Task<object>> value;
+
+        public Task<object> Value
+        {
+            get { return value.Value; }
+        }
+
+        private Deferred(Func<Task<object>> value)
+        {
+            this.value = new Lazy<Task<object>>(value);
+        }
+
+        public static Deferred Response(Func<object> factory)
+        {
+            Guard.NotNull(factory, nameof(factory));
+
+            return new Deferred(() => Task.FromResult(factory()));
+        }
+
+        public static Deferred AsyncResponse<T>(Func<Task<T>> factory)
+        {
+            Guard.NotNull(factory, nameof(factory));
+
+            return new Deferred(async () => await factory());
+        }
+    }
+}

src/Squidex.Web/ETagExtensions.cs

@@ -8,6 +8,7 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using Squidex.Domain.Apps.Entities;
 using Squidex.Infrastructure;
 using Squidex.Infrastructure.Log;
 
@@ -17,40 +18,54 @@ namespace Squidex.Web
     {
         private static readonly int GuidLength = Guid.Empty.ToString().Length;
 
-        public static string ToManyEtag<T>(this IReadOnlyList<T> items, long total = 0) where T : IGenerateETag
+        public static string ToEtag<T>(this IReadOnlyList<T> items, IEntityWithVersion app = null) where T : IEntity, IEntityWithVersion
         {
             using (Profiler.Trace("CalculateEtag"))
             {
-                var unhashed = Unhashed(items, total);
+                var unhashed = Unhashed(items, 0, app);
 
                 return unhashed.Sha256Base64();
             }
         }
 
-        private static string Unhashed<T>(IReadOnlyList<T> items, long total) where T : IGenerateETag
+        public static string ToEtag<T>(this IResultList<T> items, IEntityWithVersion app = null) where T : IEntity, IEntityWithVersion
         {
-            var sb = new StringBuilder((items.Count * (GuidLength + 4)) + 10);
+            using (Profiler.Trace("CalculateEtag"))
+            {
+                var unhashed = Unhashed(items, items.Total, app);
+
+                return unhashed.Sha256Base64();
+            }
+        }
+
+        private static string Unhashed<T>(IReadOnlyList<T> items, long total, IEntityWithVersion app) where T : IEntity, IEntityWithVersion
+        {
+            var sb = new StringBuilder((items.Count * (GuidLength + 8)) + 10);
+
+            for (var i = 0; i < items.Count; i++)
+            {
+                sb.Append(";");
+                sb.Append(items[i].ToEtag());
+            }
 
-            sb.Append(total);
             sb.Append("_");
+            sb.Append(total);
 
-            if (items.Count > 0)
+            if (app != null)
             {
-                sb.Append(items[0].Id.ToString());
-                sb.Append(items[0].Version);
-
-                for (var i = 1; i < items.Count; i++)
-                {
-                    sb.Append(";");
-                    sb.Append(items[i].Id.ToString());
-                    sb.Append(items[i].Version);
-                }
+                sb.Append("_");
+                sb.Append(app.Version);
             }
 
-            return sb.ToString().Sha256Base64();
+            return sb.ToString();
+        }
+
+        public static string ToSurrogateKey<T>(this T item) where T : IEntity
+        {
+            return item.Id.ToString();
         }
 
-        public static string ToSurrogateKeys<T>(this IReadOnlyList<T> items) where T : IGenerateETag
+        public static string ToSurrogateKeys<T>(this IReadOnlyList<T> items) where T : IEntity
         {
             if (items.Count == 0)
             {
@@ -70,9 +85,17 @@ namespace Squidex.Web
             return sb.ToString();
         }
 
-        public static string ToEtag<T>(this T item) where T : IGenerateETag
+        public static string ToEtag<T>(this T item, IEntityWithVersion app = null) where T : IEntity, IEntityWithVersion
         {
-            return item.Version.ToString();
+            var result = $"{item.Id};{item.Version}";
+
+            if (app != null)
+            {
+                result += ";";
+                result += app.Version;
+            }
+
+            return result;
         }
     }
 }

src/Squidex.Web/IGenerateEtag.cs

@@ -1,18 +0,0 @@
-// ==========================================================================
-//  Squidex Headless CMS
-// ==========================================================================
-//  Copyright (c) Squidex UG (haftungsbeschraenkt)
-//  All rights reserved. Licensed under the MIT license.
-// ==========================================================================
-
-using System;
-
-namespace Squidex.Web
-{
-    public interface IGenerateETag
-    {
-        Guid Id { get; }
-
-        long Version { get; }
-    }
-}

src/Squidex.Web/MyJsonInheritanceConverter.cs → src/Squidex.Web/Json/TypedJsonInheritanceConverter.cs

@@ -16,17 +16,16 @@ using Squidex.Infrastructure;
 
 #pragma warning disable RECS0108 // Warns about static fields in generic types
 
-namespace Squidex.Web
+namespace Squidex.Web.Json
 {
-    public class MyJsonInheritanceConverter<T> : JsonInheritanceConverter
+    public class TypedJsonInheritanceConverter<T> : JsonInheritanceConverter
     {
-        private static readonly Dictionary<string, Type> DefaultMapping = new Dictionary<string, Type>();
-        private readonly IReadOnlyDictionary<string, Type> maping;
-
-        static MyJsonInheritanceConverter()
+        private static readonly Lazy<Dictionary<string, Type>> DefaultMapping = new Lazy<Dictionary<string, Type>>(() =>
         {
             var baseName = typeof(T).Name;
 
+            var result = new Dictionary<string, Type>();
+
             void AddType(Type type)
             {
                 var discriminator = type.Name;
@@ -36,7 +35,7 @@ namespace Squidex.Web
                     discriminator = discriminator.Substring(0, discriminator.Length - baseName.Length);
                 }
 
-                DefaultMapping[discriminator] = type;
+                result[discriminator] = type;
             }
 
             foreach (var attribute in typeof(T).GetCustomAttributes<KnownTypeAttribute>())
@@ -66,17 +65,23 @@ namespace Squidex.Web
                     }
                 }
             }
-        }
 
-        public MyJsonInheritanceConverter(string discriminator)
-            : this(discriminator, DefaultMapping)
+            return result;
+        });
+
+        private readonly IReadOnlyDictionary<string, Type> maping;
+
+        public TypedJsonInheritanceConverter(string discriminator)
+            : this(discriminator, DefaultMapping.Value)
         {
         }
 
-        public MyJsonInheritanceConverter(string discriminator, IReadOnlyDictionary<string, Type> mapping)
+        public TypedJsonInheritanceConverter(string discriminator, IReadOnlyDictionary<string, Type> mapping)
             : base(typeof(T), discriminator)
         {
-            maping = mapping ?? DefaultMapping;
+            Guard.NotNull(maping, nameof(maping));
+
+            maping = mapping;
         }
 
         protected override Type GetDiscriminatorType(JObject jObject, Type objectType, string discriminatorValue)

src/Squidex.Web/Pipeline/DeferredActionFilter.cs

@@ -0,0 +1,26 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.Filters;
+
+namespace Squidex.Web.Pipeline
+{
+    public sealed class DeferredActionFilter : IAsyncActionFilter
+    {
+        public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
+        {
+            await next();
+
+            if (context.Result is ObjectResult objectResult && objectResult.Value is Deferred deferred)
+            {
+                objectResult.Value = await deferred.Value;
+            }
+        }
+    }
+}

src/Squidex.Web/ETagFilter.cs → src/Squidex.Web/Pipeline/ETagFilter.cs

@@ -12,7 +12,7 @@ using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.Extensions.Options;
 using Microsoft.Net.Http.Headers;
 
-namespace Squidex.Web
+namespace Squidex.Web.Pipeline
 {
     public sealed class ETagFilter : IAsyncActionFilter
     {

src/Squidex.Web/ETagOptions.cs → src/Squidex.Web/Pipeline/ETagOptions.cs

@@ -5,7 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-namespace Squidex.Web
+namespace Squidex.Web.Pipeline
 {
     public sealed class ETagOptions
     {

src/Squidex/Areas/Api/Controllers/Apps/AppClientsController.cs

@@ -46,9 +46,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetClients(string app)
         {
-            var response = ClientsDto.FromApp(App, this);
+            var response = Deferred.Response(() =>
+            {
+                return ClientsDto.FromApp(App, this);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/AppContributorsController.cs

@@ -48,9 +48,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetContributors(string app)
         {
-            var response = ContributorsDto.FromApp(App, appPlansProvider, this, false);
+            var response = Deferred.Response(() =>
+            {
+                return ContributorsDto.FromApp(App, appPlansProvider, this, false);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }
@@ -73,18 +76,8 @@ namespace Squidex.Areas.Api.Controllers.Apps
         public async Task<IActionResult> PostContributor(string app, [FromBody] AssignContributorDto request)
         {
             var command = request.ToCommand();
-            var context = await CommandBus.PublishAsync(command);
 
-            var response = (ContributorsDto)null;
-
-            if (context.PlainResult is IAppEntity newApp)
-            {
-                response = ContributorsDto.FromApp(newApp, appPlansProvider, this, false);
-            }
-            else if (context.PlainResult is InvitedResult invited)
-            {
-                response = ContributorsDto.FromApp(invited.App, appPlansProvider, this, true);
-            }
+            var response = await InvokeCommandAsync(command);
 
             return CreatedAtAction(nameof(GetContributors), new { app }, response);
         }
@@ -117,10 +110,14 @@ namespace Squidex.Areas.Api.Controllers.Apps
         {
             var context = await CommandBus.PublishAsync(command);
 
-            var result = context.Result<IAppEntity>();
-            var response = ContributorsDto.FromApp(result, appPlansProvider, this, false);
-
-            return response;
+            if (context.PlainResult is InvitedResult invited)
+            {
+                return ContributorsDto.FromApp(invited.App, appPlansProvider, this, true);
+            }
+            else
+            {
+                return ContributorsDto.FromApp(context.Result<IAppEntity>(), appPlansProvider, this, false);
+            }
         }
     }
 }

src/Squidex/Areas/Api/Controllers/Apps/AppLanguagesController.cs

@@ -45,9 +45,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetLanguages(string app)
         {
-            var response = AppLanguagesDto.FromApp(App, this);
+            var response = Deferred.Response(() =>
+            {
+                return AppLanguagesDto.FromApp(App, this);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/AppPatternsController.cs

@@ -47,9 +47,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetPatterns(string app)
         {
-            var response = PatternsDto.FromApp(App, this);
+            var response = Deferred.Response(() =>
+            {
+                return PatternsDto.FromApp(App, this);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/AppRolesController.cs

@@ -47,9 +47,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetRoles(string app)
         {
-            var response = RolesDto.FromApp(App, this);
+            var response = Deferred.Response(() =>
+            {
+                return RolesDto.FromApp(App, this);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }
@@ -67,11 +70,14 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ProducesResponseType(typeof(string[]), 200)]
         [ApiPermission(Permissions.AppRolesRead)]
         [ApiCosts(0)]
-        public async Task<IActionResult> GetPermissions(string app)
+        public IActionResult GetPermissions(string app)
         {
-            var response = await permissionsProvider.GetPermissionsAsync(App);
+            var response = Deferred.AsyncResponse(() =>
+            {
+                return permissionsProvider.GetPermissionsAsync(App);
+            });
 
-            Response.Headers[HeaderNames.ETag] = string.Join(";", response).Sha256Base64();
+            Response.Headers[HeaderNames.ETag] = string.Concat(response).Sha256Base64();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/AppWorkflowsController.cs

@@ -44,9 +44,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
         [ApiCosts(0)]
         public IActionResult GetWorkflows(string app)
         {
-            var response = WorkflowsDto.FromApp(App, this);
+            var response = Deferred.Response(() =>
+            {
+                return WorkflowsDto.FromApp(App, this);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/AppsController.cs

@@ -62,9 +62,12 @@ namespace Squidex.Areas.Api.Controllers.Apps
 
             var apps = await appProvider.GetUserApps(userOrClientId, userPermissions);
 
-            var response = apps.ToArray(a => AppDto.FromApp(a, userOrClientId, userPermissions, appPlansProvider, this));
+            var response = Deferred.Response(() =>
+            {
+                return apps.ToArray(a => AppDto.FromApp(a, userOrClientId, userPermissions, appPlansProvider, this));
+            });
 
-            Response.Headers[HeaderNames.ETag] = response.ToManyEtag();
+            Response.Headers[HeaderNames.ETag] = apps.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Apps/Models/AppDto.cs

@@ -25,7 +25,7 @@ using AllPermissions = Squidex.Shared.Permissions;
 
 namespace Squidex.Areas.Api.Controllers.Apps.Models
 {
-    public sealed class AppDto : Resource, IGenerateETag
+    public sealed class AppDto : Resource
     {
         /// <summary>
         /// The name of the app.

src/Squidex/Areas/Api/Controllers/Apps/Models/WorkflowsDto.cs

@@ -5,7 +5,6 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-using System;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using Squidex.Domain.Apps.Entities.Apps;

src/Squidex/Areas/Api/Controllers/Assets/AssetsController.cs

@@ -103,14 +103,17 @@ namespace Squidex.Areas.Api.Controllers.Assets
         {
             var assets = await assetQuery.QueryAsync(Context, Q.Empty.WithODataQuery(Request.QueryString.ToString()).WithIds(ids));
 
-            var response = AssetsDto.FromAssets(assets, this, app);
+            var response = Deferred.Response(() =>
+            {
+                return AssetsDto.FromAssets(assets, this, app);
+            });
 
-            if (controllerOptions.Value.EnableSurrogateKeys && response.Items.Length <= controllerOptions.Value.MaxItemsForSurrogateKeys)
+            if (controllerOptions.Value.EnableSurrogateKeys && assets.Count <= controllerOptions.Value.MaxItemsForSurrogateKeys)
             {
-                Response.Headers["Surrogate-Key"] = response.ToSurrogateKeys();
+                Response.Headers["Surrogate-Key"] = assets.ToSurrogateKeys();
             }
 
-            Response.Headers[HeaderNames.ETag] = response.ToEtag();
+            Response.Headers[HeaderNames.ETag] = assets.ToEtag();
 
             return Ok(response);
         }
@@ -138,14 +141,17 @@ namespace Squidex.Areas.Api.Controllers.Assets
                 return NotFound();
             }
 
-            var response = AssetDto.FromAsset(asset, this, app);
+            var response = Deferred.Response(() =>
+            {
+                return AssetDto.FromAsset(asset, this, app);
+            });
 
             if (controllerOptions.Value.EnableSurrogateKeys)
             {
-                Response.Headers["Surrogate-Key"] = asset.Id.ToString();
+                Response.Headers["Surrogate-Key"] = asset.ToSurrogateKey();
             }
 
-            Response.Headers[HeaderNames.ETag] = asset.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = asset.ToEtag();
 
             return Ok(response);
         }
@@ -175,10 +181,7 @@ namespace Squidex.Areas.Api.Controllers.Assets
 
             var command = new CreateAsset { File = assetFile };
 
-            var context = await CommandBus.PublishAsync(command);
-
-            var result = context.Result<AssetCreatedResult>();
-            var response = AssetDto.FromAsset(result.Asset, this, app, result.IsDuplicate);
+            var response = await InvokeCommandAsync(app, command);
 
             return CreatedAtAction(nameof(GetAsset), new { app, id = response.Id }, response);
         }
@@ -263,10 +266,14 @@ namespace Squidex.Areas.Api.Controllers.Assets
         {
             var context = await CommandBus.PublishAsync(command);
 
-            var result = context.Result<IEnrichedAssetEntity>();
-            var response = AssetDto.FromAsset(result, this, app);
-
-            return response;
+            if (context.PlainResult is AssetCreatedResult created)
+            {
+                return AssetDto.FromAsset(created.Asset, this, app, created.IsDuplicate);
+            }
+            else
+            {
+                return AssetDto.FromAsset(context.Result<IEnrichedAssetEntity>(), this, app);
+            }
         }
 
         private async Task<AssetFile> CheckAssetFileAsync(IReadOnlyList<IFormFile> file)

src/Squidex/Areas/Api/Controllers/Assets/Models/AssetDto.cs

@@ -18,7 +18,7 @@ using Squidex.Web;
 
 namespace Squidex.Areas.Api.Controllers.Assets.Models
 {
-    public sealed class AssetDto : Resource, IGenerateETag
+    public sealed class AssetDto : Resource
     {
         /// <summary>
         /// The id of the asset.

src/Squidex/Areas/Api/Controllers/Assets/Models/AssetsDto.cs

@@ -27,16 +27,6 @@ namespace Squidex.Areas.Api.Controllers.Assets.Models
         [Required]
         public AssetDto[] Items { get; set; }
 
-        public string ToEtag()
-        {
-            return Items.ToManyEtag(Total);
-        }
-
-        public string ToSurrogateKeys()
-        {
-            return Items.ToSurrogateKeys();
-        }
-
         public static AssetsDto FromAssets(IResultList<IEnrichedAssetEntity> assets, ApiController controller, string app)
         {
             var response = new AssetsDto

src/Squidex/Areas/Api/Controllers/Comments/CommentsController.cs

@@ -55,9 +55,13 @@ namespace Squidex.Areas.Api.Controllers.Comments
         public async Task<IActionResult> GetComments(string app, Guid commentsId, [FromQuery] long version = EtagVersion.Any)
         {
             var result = await grainFactory.GetGrain<ICommentGrain>(commentsId).GetCommentsAsync(version);
-            var response = CommentsDto.FromResult(result);
 
-            Response.Headers[HeaderNames.ETag] = response.Version.ToString();
+            var response = Deferred.Response(() =>
+            {
+                return CommentsDto.FromResult(result);
+            });
+
+            Response.Headers[HeaderNames.ETag] = result.Version.ToString();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Contents/ContentsController.cs

@@ -6,6 +6,7 @@
 // ==========================================================================
 
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Options;
@@ -126,14 +127,17 @@ namespace Squidex.Areas.Api.Controllers.Contents
         {
             var contents = await contentQuery.QueryAsync(Context, Q.Empty.WithIds(ids).Ids);
 
-            var response = await ContentsDto.FromContentsAsync(contents, Context, this, null, contentWorkflow);
+            var response = Deferred.AsyncResponse(() =>
+            {
+                return ContentsDto.FromContentsAsync(contents, Context, this, null, contentWorkflow);
+            });
 
-            if (controllerOptions.Value.EnableSurrogateKeys && response.Items.Length <= controllerOptions.Value.MaxItemsForSurrogateKeys)
+            if (ShouldProvideSurrogateKeys(contents))
             {
-                Response.Headers["Surrogate-Key"] = response.ToSurrogateKeys();
+                Response.Headers["Surrogate-Key"] = contents.ToSurrogateKeys();
             }
 
-            Response.Headers[HeaderNames.ETag] = $"{response.ToEtag()}_{App.Version}";
+            Response.Headers[HeaderNames.ETag] = contents.ToEtag(App);
 
             return Ok(response);
         }
@@ -160,16 +164,19 @@ namespace Squidex.Areas.Api.Controllers.Contents
         {
             var contents = await contentQuery.QueryAsync(Context, name, Q.Empty.WithIds(ids).WithODataQuery(Request.QueryString.ToString()));
 
-            var schema = await contentQuery.GetSchemaOrThrowAsync(Context, name);
+            var response = Deferred.AsyncResponse(async () =>
+            {
+                var schema = await contentQuery.GetSchemaOrThrowAsync(Context, name);
 
-            var response = await ContentsDto.FromContentsAsync(contents, Context, this, schema, contentWorkflow);
+                return await ContentsDto.FromContentsAsync(contents, Context, this, schema, contentWorkflow);
+            });
 
-            if (ShouldProvideSurrogateKeys(response))
+            if (ShouldProvideSurrogateKeys(contents))
             {
-                Response.Headers["Surrogate-Key"] = response.ToSurrogateKeys();
+                Response.Headers["Surrogate-Key"] = contents.ToSurrogateKeys();
             }
 
-            Response.Headers[HeaderNames.ETag] = $"{response.ToEtag()}_{App.Version}";
+            Response.Headers[HeaderNames.ETag] = contents.ToEtag(App);
 
             return Ok(response);
         }
@@ -200,10 +207,10 @@ namespace Squidex.Areas.Api.Controllers.Contents
 
             if (controllerOptions.Value.EnableSurrogateKeys)
             {
-                Response.Headers["Surrogate-Key"] = content.Id.ToString();
+                Response.Headers["Surrogate-Key"] = content.ToSurrogateKey();
             }
 
-            Response.Headers[HeaderNames.ETag] = $"{response.ToEtag()}_{App.Version}";
+            Response.Headers[HeaderNames.ETag] = content.ToEtag(App);
 
             return Ok(response);
         }
@@ -235,10 +242,10 @@ namespace Squidex.Areas.Api.Controllers.Contents
 
             if (controllerOptions.Value.EnableSurrogateKeys)
             {
-                Response.Headers["Surrogate-Key"] = content.Id.ToString();
+                Response.Headers["Surrogate-Key"] = content.ToSurrogateKey();
             }
 
-            Response.Headers[HeaderNames.ETag] = $"{response.ToEtag()}_{App.Version}";
+            Response.Headers[HeaderNames.ETag] = content.ToEtag(App);
 
             return Ok(response.Data);
         }
@@ -447,9 +454,9 @@ namespace Squidex.Areas.Api.Controllers.Contents
             return response;
         }
 
-        private bool ShouldProvideSurrogateKeys(ContentsDto response)
+        private bool ShouldProvideSurrogateKeys(IReadOnlyList<IContentEntity> response)
         {
-            return controllerOptions.Value.EnableSurrogateKeys && response.Items.Length <= controllerOptions.Value.MaxItemsForSurrogateKeys;
+            return controllerOptions.Value.EnableSurrogateKeys && response.Count <= controllerOptions.Value.MaxItemsForSurrogateKeys;
         }
     }
 }

src/Squidex/Areas/Api/Controllers/Contents/Models/ContentDto.cs

@@ -19,7 +19,7 @@ using Squidex.Web;
 
 namespace Squidex.Areas.Api.Controllers.Contents.Models
 {
-    public sealed class ContentDto : Resource, IGenerateETag
+    public sealed class ContentDto : Resource
     {
         /// <summary>
         /// The if of the content item.

src/Squidex/Areas/Api/Controllers/Contents/Models/ContentsDto.cs

@@ -37,16 +37,6 @@ namespace Squidex.Areas.Api.Controllers.Contents.Models
         [Required]
         public StatusInfoDto[] Statuses { get; set; }
 
-        public string ToEtag()
-        {
-            return Items.ToManyEtag(Total);
-        }
-
-        public string ToSurrogateKeys()
-        {
-            return Items.ToSurrogateKeys();
-        }
-
         public static async Task<ContentsDto> FromContentsAsync(IResultList<IEnrichedContentEntity> contents,
             Context context, ApiController controller, ISchemaEntity schema, IContentWorkflow contentWorkflow)
         {

src/Squidex/Areas/Api/Controllers/Languages/LanguagesController.cs

@@ -40,7 +40,10 @@ namespace Squidex.Areas.Api.Controllers.Languages
         [ApiPermission]
         public IActionResult GetLanguages()
         {
-            var response = Language.AllLanguages.Select(LanguageDto.FromLanguage).ToArray();
+            var response = Deferred.Response(() =>
+            {
+                return Language.AllLanguages.Select(LanguageDto.FromLanguage).ToArray();
+            });
 
             Response.Headers[HeaderNames.ETag] = "1";
 

src/Squidex/Areas/Api/Controllers/Plans/AppPlansController.cs

@@ -51,9 +51,12 @@ namespace Squidex.Areas.Api.Controllers.Plans
         {
             var hasPortal = appPlansBillingManager.HasPortal;
 
-            var response = AppPlansDto.FromApp(App, appPlansProvider, hasPortal);
+            var response = Deferred.Response(() =>
+            {
+                return AppPlansDto.FromApp(App, appPlansProvider, hasPortal);
+            });
 
-            Response.Headers[HeaderNames.ETag] = App.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = App.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Rules/Models/RuleActionConverter.cs

@@ -8,11 +8,11 @@
 using System;
 using System.Collections.Generic;
 using Squidex.Domain.Apps.Core.Rules;
-using Squidex.Web;
+using Squidex.Web.Json;
 
 namespace Squidex.Areas.Api.Controllers.Rules.Models
 {
-    public sealed class RuleActionConverter : MyJsonInheritanceConverter<RuleAction>
+    public sealed class RuleActionConverter : TypedJsonInheritanceConverter<RuleAction>
     {
         public static IReadOnlyDictionary<string, Type> Mapping { get; set; }
 

src/Squidex/Areas/Api/Controllers/Rules/Models/RuleDto.cs

@@ -19,7 +19,7 @@ using Squidex.Web;
 
 namespace Squidex.Areas.Api.Controllers.Rules.Models
 {
-    public sealed class RuleDto : Resource, IGenerateETag
+    public sealed class RuleDto : Resource
     {
         /// <summary>
         /// The id of the rule.

src/Squidex/Areas/Api/Controllers/Rules/Models/RuleTriggerDto.cs

@@ -10,11 +10,11 @@ using System.Linq;
 using System.Runtime.Serialization;
 using Newtonsoft.Json;
 using Squidex.Domain.Apps.Core.Rules;
-using Squidex.Web;
+using Squidex.Web.Json;
 
 namespace Squidex.Areas.Api.Controllers.Rules.Models
 {
-    [JsonConverter(typeof(MyJsonInheritanceConverter<RuleTriggerDto>), "triggerType")]
+    [JsonConverter(typeof(TypedJsonInheritanceConverter<RuleTriggerDto>), "triggerType")]
     [KnownType(nameof(Subtypes))]
     public abstract class RuleTriggerDto
     {

src/Squidex/Areas/Api/Controllers/Rules/Models/RulesDto.cs

@@ -22,11 +22,6 @@ namespace Squidex.Areas.Api.Controllers.Rules.Models
         [Required]
         public RuleDto[] Items { get; set; }
 
-        public string GenerateEtag()
-        {
-            return Items.ToManyEtag(0);
-        }
-
         public static RulesDto FromRules(IEnumerable<IRuleEntity> items, ApiController controller, string app)
         {
             var result = new RulesDto

src/Squidex/Areas/Api/Controllers/Rules/RulesController.cs

@@ -58,9 +58,12 @@ namespace Squidex.Areas.Api.Controllers.Rules
         [ApiCosts(0)]
         public IActionResult GetActions()
         {
-            var etag = string.Join(";", ruleRegistry.Actions.Select(x => x.Key)).Sha256Base64();
+            var etag = string.Concat(ruleRegistry.Actions.Select(x => x.Key)).Sha256Base64();
 
-            var response = ruleRegistry.Actions.ToDictionary(x => x.Key, x => RuleElementDto.FromDefinition(x.Value));
+            var response = Deferred.Response(() =>
+            {
+                return ruleRegistry.Actions.ToDictionary(x => x.Key, x => RuleElementDto.FromDefinition(x.Value));
+            });
 
             Response.Headers[HeaderNames.ETag] = etag;
 
@@ -84,9 +87,12 @@ namespace Squidex.Areas.Api.Controllers.Rules
         {
             var rules = await appProvider.GetRulesAsync(AppId);
 
-            var response = RulesDto.FromRules(rules, this, app);
+            var response = Deferred.Response(() =>
+            {
+                return RulesDto.FromRules(rules, this, app);
+            });
 
-            Response.Headers[HeaderNames.ETag] = response.GenerateEtag();
+            Response.Headers[HeaderNames.ETag] = rules.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Areas/Api/Controllers/Schemas/Models/FieldPropertiesDto.cs

@@ -11,11 +11,11 @@ using System.Linq;
 using System.Runtime.Serialization;
 using Newtonsoft.Json;
 using Squidex.Domain.Apps.Core.Schemas;
-using Squidex.Web;
+using Squidex.Web.Json;
 
 namespace Squidex.Areas.Api.Controllers.Schemas.Models
 {
-    [JsonConverter(typeof(MyJsonInheritanceConverter<FieldPropertiesDto>), "fieldType")]
+    [JsonConverter(typeof(TypedJsonInheritanceConverter<FieldPropertiesDto>), "fieldType")]
     [KnownType(nameof(Subtypes))]
     public abstract class FieldPropertiesDto
     {

src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemaDto.cs

@@ -17,7 +17,7 @@ using Squidex.Web;
 
 namespace Squidex.Areas.Api.Controllers.Schemas.Models
 {
-    public class SchemaDto : Resource, IGenerateETag
+    public class SchemaDto : Resource
     {
         /// <summary>
         /// The id of the schema.

src/Squidex/Areas/Api/Controllers/Schemas/Models/SchemasDto.cs

@@ -21,11 +21,6 @@ namespace Squidex.Areas.Api.Controllers.Schemas.Models
         /// </summary>
         public SchemaDto[] Items { get; set; }
 
-        public string ToEtag()
-        {
-            return Items.ToManyEtag();
-        }
-
         public static SchemasDto FromSchemas(IList<ISchemaEntity> schemas, ApiController controller, string app)
         {
             var result = new SchemasDto

src/Squidex/Areas/Api/Controllers/Schemas/SchemasController.cs

@@ -50,9 +50,12 @@ namespace Squidex.Areas.Api.Controllers.Schemas
         {
             var schemas = await appProvider.GetSchemasAsync(AppId);
 
-            var response = SchemasDto.FromSchemas(schemas, this, app);
+            var response = Deferred.Response(() =>
+            {
+                return SchemasDto.FromSchemas(schemas, this, app);
+            });
 
-            Response.Headers[HeaderNames.ETag] = response.ToEtag();
+            Response.Headers[HeaderNames.ETag] = schemas.ToEtag();
 
             return Ok(response);
         }
@@ -89,9 +92,12 @@ namespace Squidex.Areas.Api.Controllers.Schemas
                 return NotFound();
             }
 
-            var response = SchemaDetailsDto.FromSchemaWithDetails(schema, this, app);
+            var response = Deferred.Response(() =>
+            {
+                return SchemaDetailsDto.FromSchemaWithDetails(schema, this, app);
+            });
 
-            Response.Headers[HeaderNames.ETag] = schema.Version.ToString();
+            Response.Headers[HeaderNames.ETag] = schema.ToEtag();
 
             return Ok(response);
         }

src/Squidex/Config/Domain/SerializationInitializer.cs

@@ -29,6 +29,7 @@ namespace Squidex.Config.Domain
         {
             this.jsonNetSerializer = jsonNetSerializer;
             this.jsonSerializer = jsonSerializer;
+
             this.ruleRegistry = ruleRegistry;
         }
 

src/Squidex/Config/Web/WebServices.cs

@@ -51,6 +51,7 @@ namespace Squidex.Config.Web
             services.AddMvc(options =>
             {
                 options.Filters.Add<ETagFilter>();
+                options.Filters.Add<DeferredActionFilter>();
                 options.Filters.Add<AppResolver>();
                 options.Filters.Add<MeasureResultFilter>();
             })