Tests fixed.

src/Squidex.Domain.Apps.Core.Model/Partitioning.cs

@@ -45,5 +45,12 @@ namespace Squidex.Domain.Apps.Core
         {
             return Key;
         }
+
+        public static Partitioning FromString(string value)
+        {
+            var isLanguage = string.Equals(value, Language.Key, StringComparison.OrdinalIgnoreCase);
+
+            return isLanguage ? Language : Invariant;
+        }
     }
 }

src/Squidex.Domain.Apps.Core.Model/Schemas/ArrayField.cs

@@ -11,7 +11,7 @@ using System.Diagnostics.Contracts;
 
 namespace Squidex.Domain.Apps.Core.Schemas
 {
-    public sealed class ArrayField : RootField<ArrayFieldProperties>
+    public sealed class ArrayField : RootField<ArrayFieldProperties>, IArrayField
     {
         private FieldCollection<NestedField> fields = FieldCollection<NestedField>.Empty;
 

src/Squidex.Domain.Apps.Core.Model/Schemas/ArrayFieldProperties.cs

@@ -24,7 +24,7 @@ namespace Squidex.Domain.Apps.Core.Schemas
 
         public override T Accept<T>(IFieldVisitor<T> visitor, IField field)
         {
-            return visitor.Visit((IField<AssetsFieldProperties>)field);
+            return visitor.Visit((IArrayField)field);
         }
 
         public override RootField CreateRootField(long id, string name, Partitioning partitioning)

src/Squidex.Domain.Apps.Core.Model/Schemas/FieldExtensions.cs

@@ -0,0 +1,145 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Collections.Generic;
+
+namespace Squidex.Domain.Apps.Core.Schemas
+{
+    public static class FieldExtensions
+    {
+        public static Schema LockField(this Schema schema, long fieldId)
+        {
+            return schema.UpdateField(fieldId, f => f.Lock());
+        }
+
+        public static Schema ReorderFields(this Schema schema, List<long> ids, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.ReorderFields(ids);
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.ReorderFields(ids);
+        }
+
+        public static Schema DeleteField(this Schema schema, long fieldId, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.DeleteField(fieldId);
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.DeleteField(fieldId);
+        }
+
+        public static Schema HideField(this Schema schema, long fieldId, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.UpdateField(fieldId, n => n.Hide());
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.UpdateField(fieldId, f => f.Hide());
+        }
+
+        public static Schema ShowField(this Schema schema, long fieldId, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.UpdateField(fieldId, n => n.Show());
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.UpdateField(fieldId, f => f.Show());
+        }
+
+        public static Schema EnableField(this Schema schema, long fieldId, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.UpdateField(fieldId, n => n.Enable());
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.UpdateField(fieldId, f => f.Enable());
+        }
+
+        public static Schema DisableField(this Schema schema, long fieldId, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.UpdateField(fieldId, n => n.Disable());
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.UpdateField(fieldId, f => f.Disable());
+        }
+
+        public static Schema UpdateField(this Schema schema, long fieldId, FieldProperties properties, long? parentId = null)
+        {
+            if (parentId != null)
+            {
+                return schema.UpdateField(parentId.Value, f =>
+                {
+                    if (f is ArrayField arrayField)
+                    {
+                        return arrayField.UpdateField(fieldId, n => n.Update(properties));
+                    }
+
+                    return f;
+                });
+            }
+
+            return schema.UpdateField(fieldId, f => f.Update(properties));
+        }
+    }
+}

src/Squidex.Domain.Apps.Core.Model/Schemas/FieldRegistry.cs

@@ -49,7 +49,7 @@ namespace Squidex.Domain.Apps.Core.Schemas
             return properties.CreateRootField(id, name, partitioning);
         }
 
-        public NestedField CreateNestedField(long id, string name, Partitioning partitioning, FieldProperties properties)
+        public NestedField CreateNestedField(long id, string name, FieldProperties properties)
         {
             CheckProperties(properties);
 

src/Squidex.Domain.Apps.Core.Model/Schemas/Fields.cs

@@ -5,13 +5,30 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System;
+
 namespace Squidex.Domain.Apps.Core.Schemas
 {
     public static class Fields
     {
-        public static RootField<ArrayFieldProperties> Array(long id, string name, Partitioning partitioning, ArrayFieldProperties properties = null)
+        public static RootField<ArrayFieldProperties> Array(long id, string name, Partitioning partitioning, params NestedField[] fields)
+        {
+            var result = new ArrayField(id, name, partitioning, new ArrayFieldProperties());
+
+            if (fields != null)
+            {
+                foreach (var field in fields)
+                {
+                    result = result.AddField(field);
+                }
+            }
+
+            return result;
+        }
+
+        public static ArrayField Array(long id, string name, Partitioning partitioning, ArrayFieldProperties properties = null)
         {
-            return new RootField<ArrayFieldProperties>(id, name, partitioning, properties ?? new ArrayFieldProperties());
+            return new ArrayField(id, name, partitioning, properties ?? new ArrayFieldProperties());
         }
 
         public static RootField<AssetsFieldProperties> Assets(long id, string name, Partitioning partitioning, AssetsFieldProperties properties = null)
@@ -104,6 +121,18 @@ namespace Squidex.Domain.Apps.Core.Schemas
             return new NestedField<TagsFieldProperties>(id, name, properties ?? new TagsFieldProperties());
         }
 
+        public static Schema AddArray(this Schema schema, long id, string name, Partitioning partitioning, Func<ArrayField, ArrayField> handler, ArrayFieldProperties properties = null)
+        {
+            var field = Array(id, name, partitioning, properties);
+
+            if (handler != null)
+            {
+                field = handler(field);
+            }
+
+            return schema.AddField(field);
+        }
+
         public static Schema AddAssets(this Schema schema, long id, string name, Partitioning partitioning, AssetsFieldProperties properties = null)
         {
             return schema.AddField(Assets(id, name, partitioning, properties));
@@ -148,5 +177,50 @@ namespace Squidex.Domain.Apps.Core.Schemas
         {
             return schema.AddField(Tags(id, name, partitioning, properties));
         }
+
+        public static ArrayField AddAssets(this ArrayField field, long id, string name, AssetsFieldProperties properties = null)
+        {
+            return field.AddField(Assets(id, name, properties));
+        }
+
+        public static ArrayField AddBoolean(this ArrayField field, long id, string name, BooleanFieldProperties properties = null)
+        {
+            return field.AddField(Boolean(id, name, properties));
+        }
+
+        public static ArrayField AddDateTime(this ArrayField field, long id, string name, DateTimeFieldProperties properties = null)
+        {
+            return field.AddField(DateTime(id, name, properties));
+        }
+
+        public static ArrayField AddGeolocation(this ArrayField field, long id, string name, GeolocationFieldProperties properties = null)
+        {
+            return field.AddField(Geolocation(id, name, properties));
+        }
+
+        public static ArrayField AddJson(this ArrayField field, long id, string name, JsonFieldProperties properties = null)
+        {
+            return field.AddField(Json(id, name, properties));
+        }
+
+        public static ArrayField AddNumber(this ArrayField field, long id, string name, NumberFieldProperties properties = null)
+        {
+            return field.AddField(Number(id, name, properties));
+        }
+
+        public static ArrayField AddReferences(this ArrayField field, long id, string name, ReferencesFieldProperties properties = null)
+        {
+            return field.AddField(References(id, name, properties));
+        }
+
+        public static ArrayField AddString(this ArrayField field, long id, string name, StringFieldProperties properties = null)
+        {
+            return field.AddField(String(id, name, properties));
+        }
+
+        public static ArrayField AddTags(this ArrayField field, long id, string name, TagsFieldProperties properties = null)
+        {
+            return field.AddField(Tags(id, name, properties));
+        }
     }
 }

src/Squidex.Domain.Apps.Core.Model/Schemas/IArrayField.cs

@@ -11,10 +11,10 @@ namespace Squidex.Domain.Apps.Core.Schemas
 {
     public interface IArrayField : IField<ArrayFieldProperties>
     {
-        IReadOnlyList<INestedField> Fields { get; }
+        IReadOnlyList<NestedField> Fields { get; }
 
-        IReadOnlyDictionary<long, INestedField> FieldsById { get; }
+        IReadOnlyDictionary<long, NestedField> FieldsById { get; }
 
-        IReadOnlyDictionary<string, INestedField> FieldsByName { get; }
+        IReadOnlyDictionary<string, NestedField> FieldsByName { get; }
     }
 }

src/Squidex.Domain.Apps.Core.Model/Schemas/IField.cs

@@ -13,6 +13,8 @@ namespace Squidex.Domain.Apps.Core.Schemas
 
         string Name { get; }
 
+        bool IsLocked { get; }
+
         bool IsDisabled { get; }
 
         bool IsHidden { get; }

src/Squidex.Domain.Apps.Core.Model/Schemas/IRootField.cs

@@ -9,8 +9,6 @@ namespace Squidex.Domain.Apps.Core.Schemas
 {
     public interface IRootField : IField
     {
-        bool IsLocked { get; }
-
         Partitioning Partitioning { get; }
     }
 }

src/Squidex.Domain.Apps.Core.Model/Schemas/Json/JsonFieldModel.cs

@@ -5,6 +5,7 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System.Collections.Generic;
 using Newtonsoft.Json;
 
 namespace Squidex.Domain.Apps.Core.Schemas.Json
@@ -15,21 +16,24 @@ namespace Squidex.Domain.Apps.Core.Schemas.Json
         public long Id { get; set; }
 
         [JsonProperty]
-        public bool IsHidden { get; set; }
+        public string Name { get; set; }
 
         [JsonProperty]
-        public bool IsLocked { get; set; }
+        public string Partitioning { get; set; }
 
         [JsonProperty]
-        public bool IsDisabled { get; set; }
+        public bool IsHidden { get; set; }
 
         [JsonProperty]
-        public string Name { get; set; }
+        public bool IsLocked { get; set; }
 
         [JsonProperty]
-        public string Partitioning { get; set; }
+        public bool IsDisabled { get; set; }
 
         [JsonProperty]
         public FieldProperties Properties { get; set; }
+
+        [JsonProperty]
+        public List<JsonNestedFieldModel> Children { get; set; }
     }
 }

src/Squidex.Domain.Apps.Core.Model/Schemas/Json/JsonNestedFieldModel.cs

@@ -0,0 +1,29 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using Newtonsoft.Json;
+
+namespace Squidex.Domain.Apps.Core.Schemas.Json
+{
+    public sealed class JsonNestedFieldModel
+    {
+        [JsonProperty]
+        public long Id { get; set; }
+
+        [JsonProperty]
+        public string Name { get; set; }
+
+        [JsonProperty]
+        public bool IsHidden { get; set; }
+
+        [JsonProperty]
+        public bool IsDisabled { get; set; }
+
+        [JsonProperty]
+        public FieldProperties Properties { get; set; }
+    }
+}

src/Squidex.Domain.Apps.Core.Model/Schemas/Json/JsonSchemaModel.cs

@@ -38,11 +38,12 @@ namespace Squidex.Domain.Apps.Core.Schemas.Json
             Properties = schema.Properties;
 
             Fields =
-                schema.Fields?.Select(x =>
+                schema.Fields.Select(x =>
                     new JsonFieldModel
                     {
                         Id = x.Id,
                         Name = x.Name,
+                        Children = CreateChildren(x),
                         IsHidden = x.IsHidden,
                         IsLocked = x.IsLocked,
                         IsDisabled = x.IsDisabled,
@@ -53,7 +54,25 @@ namespace Squidex.Domain.Apps.Core.Schemas.Json
             IsPublished = schema.IsPublished;
         }
 
-        public Schema ToSchema(FieldRegistry fieldRegistry)
+        private static List<JsonNestedFieldModel> CreateChildren(IField field)
+        {
+            if (field is ArrayField arrayField)
+            {
+                return arrayField.Fields.Select(x =>
+                    new JsonNestedFieldModel
+                    {
+                        Id = x.Id,
+                        Name = x.Name,
+                        IsHidden = x.IsHidden,
+                        IsDisabled = x.IsDisabled,
+                        Properties = x.RawProperties
+                    }).ToList();
+            }
+
+            return null;
+        }
+
+        public Schema ToSchema(FieldRegistry registry)
         {
             RootField[] fields = Empty;
 
@@ -67,7 +86,29 @@ namespace Squidex.Domain.Apps.Core.Schemas.Json
 
                     var parititonKey = new Partitioning(fieldModel.Partitioning);
 
-                    var field = fieldRegistry.CreateRootField(fieldModel.Id, fieldModel.Name, parititonKey, fieldModel.Properties);
+                    var field = registry.CreateRootField(fieldModel.Id, fieldModel.Name, parititonKey, fieldModel.Properties);
+
+                    if (field is ArrayField arrayField && fieldModel.Children?.Count > 0)
+                    {
+                        foreach (var nestedFieldModel in fieldModel.Children)
+                        {
+                            var nestedField = registry.CreateNestedField(nestedFieldModel.Id, nestedFieldModel.Name, nestedFieldModel.Properties);
+
+                            if (nestedFieldModel.IsHidden)
+                            {
+                                nestedField = nestedField.Hide();
+                            }
+
+                            if (nestedFieldModel.IsDisabled)
+                            {
+                                nestedField = nestedField.Disable();
+                            }
+
+                            arrayField = arrayField.AddField(nestedField);
+                        }
+
+                        field = arrayField;
+                    }
 
                     if (fieldModel.IsDisabled)
                     {

src/Squidex.Domain.Apps.Core.Model/Schemas/NestedField.cs

@@ -37,6 +37,11 @@ namespace Squidex.Domain.Apps.Core.Schemas
             get { return isDisabled; }
         }
 
+        public bool IsLocked
+        {
+            get { return false; }
+        }
+
         public abstract FieldProperties RawProperties { get; }
 
         protected NestedField(long id, string name)

src/Squidex.Domain.Apps.Core.Operations/GenerateJsonSchema/JsonTypeVisitor.cs

@@ -33,7 +33,7 @@ namespace Squidex.Domain.Apps.Core.GenerateJsonSchema
 
                 foreach (var nestedField in field.Fields.Where(x => !x.IsHidden))
                 {
-                    var childProperty = field.Accept(this);
+                    var childProperty = nestedField.Accept(this);
 
                     childProperty.Description = nestedField.RawProperties.Hints;
                     childProperty.IsRequired = nestedField.RawProperties.IsRequired;

src/Squidex.Domain.Apps.Entities/Schemas/Commands/AddField.cs

@@ -11,6 +11,8 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Commands
 {
     public sealed class AddField : SchemaCommand
     {
+        public long? ParentFieldId { get; set; }
+
         public string Name { get; set; }
 
         public string Partitioning { get; set; }

src/Squidex.Domain.Apps.Entities/Schemas/Commands/FieldCommand.cs

@@ -9,6 +9,8 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Commands
 {
     public class FieldCommand : SchemaCommand
     {
+        public long? ParentFieldId { get; set; }
+
         public long FieldId { get; set; }
     }
 }

src/Squidex.Domain.Apps.Entities/Schemas/Guards/GuardSchemaField.cs

@@ -68,7 +68,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
                 }
             });
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (field.IsLocked)
             {
@@ -80,7 +80,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
         {
             Guard.NotNull(command, nameof(command));
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (field.IsLocked)
             {
@@ -92,7 +92,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
         {
             Guard.NotNull(command, nameof(command));
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (field.IsHidden)
             {
@@ -104,7 +104,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
         {
             Guard.NotNull(command, nameof(command));
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (!field.IsHidden)
             {
@@ -116,7 +116,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
         {
             Guard.NotNull(command, nameof(command));
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (field.IsDisabled)
             {
@@ -126,7 +126,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
 
         public static void CanEnable(Schema schema, EnableField command)
         {
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, command.ParentFieldId);
 
             if (!field.IsDisabled)
             {
@@ -138,7 +138,7 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
         {
             Guard.NotNull(command, nameof(command));
 
-            var field = GetFieldOrThrow(schema, command.FieldId);
+            var field = GetFieldOrThrow(schema, command.FieldId, null);
 
             if (field.IsLocked)
             {
@@ -146,8 +146,23 @@ namespace Squidex.Domain.Apps.Entities.Schemas.Guards
             }
         }
 
-        private static IRootField GetFieldOrThrow(Schema schema, long fieldId)
+        private static IField GetFieldOrThrow(Schema schema, long fieldId, long? parentId)
         {
+            if (parentId.HasValue)
+            {
+                if (!schema.FieldsById.TryGetValue(parentId.Value, out var rootField) || !(rootField is ArrayField arrayField))
+                {
+                    throw new DomainObjectNotFoundException(parentId.ToString(), "Fields", typeof(Schema));
+                }
+
+                if (!arrayField.FieldsById.TryGetValue(fieldId, out var nestedField))
+                {
+                    throw new DomainObjectNotFoundException(fieldId.ToString(), $"Fields[{parentId}].Fields", typeof(Schema));
+                }
+
+                return nestedField;
+            }
+
             if (!schema.FieldsById.TryGetValue(fieldId, out var field))
             {
                 throw new DomainObjectNotFoundException(fieldId.ToString(), "Fields", typeof(Schema));

src/Squidex.Domain.Apps.Entities/Schemas/State/SchemaState.cs

@@ -83,13 +83,34 @@ namespace Squidex.Domain.Apps.Entities.Schemas.State
                 {
                     TotalFields++;
 
-                    var partitioning =
-                        string.Equals(eventField.Partitioning, Partitioning.Language.Key, StringComparison.OrdinalIgnoreCase) ?
-                            Partitioning.Language :
-                            Partitioning.Invariant;
+                    var partitioning = Partitioning.FromString(eventField.Partitioning);
 
                     var field = registry.CreateRootField(TotalFields, eventField.Name, partitioning, eventField.Properties);
 
+                    if (field is ArrayField arrayField && eventField.Children?.Count > 0)
+                    {
+                        foreach (var nestedEventField in eventField.Children)
+                        {
+                            TotalFields++;
+
+                            var nestedField = registry.CreateNestedField(TotalFields, nestedEventField.Name, nestedEventField.Properties);
+
+                            if (nestedEventField.IsHidden)
+                            {
+                                nestedField = nestedField.Hide();
+                            }
+
+                            if (nestedEventField.IsDisabled)
+                            {
+                                nestedField = nestedField.Disable();
+                            }
+
+                            arrayField = arrayField.AddField(nestedField);
+                        }
+
+                        field = arrayField;
+                    }
+
                     if (eventField.IsHidden)
                     {
                         field = field.Hide();
@@ -116,15 +137,21 @@ namespace Squidex.Domain.Apps.Entities.Schemas.State
 
         protected void On(FieldAdded @event, FieldRegistry registry)
         {
-            var partitioning =
-                string.Equals(@event.Partitioning, Partitioning.Language.Key, StringComparison.OrdinalIgnoreCase) ?
-                    Partitioning.Language :
-                    Partitioning.Invariant;
+            if (@event.ParentFieldId != null)
+            {
+                var field = registry.CreateNestedField(@event.FieldId.Id, @event.Name, @event.Properties);
+
+                SchemaDef = SchemaDef.UpdateField(@event.ParentFieldId.Id, x => ((ArrayField)x).AddField(field));
+            }
+            else
+            {
+                var partitioning = Partitioning.FromString(@event.Partitioning);
 
-            var field = registry.CreateRootField(@event.FieldId.Id, @event.Name, partitioning, @event.Properties);
+                var field = registry.CreateRootField(@event.FieldId.Id, @event.Name, partitioning, @event.Properties);
 
-            SchemaDef = SchemaDef.DeleteField(@event.FieldId.Id);
-            SchemaDef = SchemaDef.AddField(field);
+                SchemaDef = SchemaDef.DeleteField(@event.FieldId.Id);
+                SchemaDef = SchemaDef.AddField(field);
+            }
 
             TotalFields++;
         }
@@ -151,42 +178,42 @@ namespace Squidex.Domain.Apps.Entities.Schemas.State
 
         protected void On(SchemaFieldsReordered @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.ReorderFields(@event.FieldIds);
+            SchemaDef = SchemaDef.ReorderFields(@event.FieldIds, @event.ParentFieldIdId?.Id);
         }
 
         protected void On(FieldUpdated @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Update(@event.Properties));
+            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, @event.Properties, @event.ParentFieldId?.Id);
         }
 
         protected void On(FieldLocked @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Lock());
+            SchemaDef = SchemaDef.LockField(@event.FieldId.Id);
         }
 
         protected void On(FieldDisabled @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Disable());
+            SchemaDef = SchemaDef.DisableField(@event.FieldId.Id, @event.ParentFieldId?.Id);
         }
 
         protected void On(FieldEnabled @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Enable());
+            SchemaDef = SchemaDef.EnableField(@event.FieldId.Id, @event.ParentFieldId?.Id);
         }
 
         protected void On(FieldHidden @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Hide());
+            SchemaDef = SchemaDef.HideField(@event.FieldId.Id, @event.ParentFieldId?.Id);
         }
 
         protected void On(FieldShown @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.UpdateField(@event.FieldId.Id, f => f.Show());
+            SchemaDef = SchemaDef.ShowField(@event.FieldId.Id, @event.ParentFieldId?.Id);
         }
 
         protected void On(FieldDeleted @event, FieldRegistry registry)
         {
-            SchemaDef = SchemaDef.DeleteField(@event.FieldId.Id);
+            SchemaDef = SchemaDef.DeleteField(@event.FieldId.Id, @event.ParentFieldId?.Id);
         }
 
         protected void On(SchemaDeleted @event, FieldRegistry registry)

src/Squidex.Domain.Apps.Events/Schemas/FieldEvent.cs

@@ -12,5 +12,7 @@ namespace Squidex.Domain.Apps.Events.Schemas
     public abstract class FieldEvent : SchemaEvent
     {
         public NamedId<long> FieldId { get; set; }
+
+        public NamedId<long> ParentFieldId { get; set; }
     }
 }

src/Squidex.Domain.Apps.Events/Schemas/SchemaCreatedField.cs

@@ -6,6 +6,7 @@
 // ==========================================================================
 
 using Squidex.Domain.Apps.Core.Schemas;
+using FieldChildren = System.Collections.Generic.List<Squidex.Domain.Apps.Events.Schemas.SchemaCreatedNestedField>;
 
 namespace Squidex.Domain.Apps.Events.Schemas
 {
@@ -21,6 +22,8 @@ namespace Squidex.Domain.Apps.Events.Schemas
 
         public bool IsDisabled { get; set; }
 
+        public FieldChildren Children { get; set; }
+
         public FieldProperties Properties { get; set; }
     }
 }

src/Squidex.Domain.Apps.Events/Schemas/SchemaCreatedNestedField.cs

@@ -0,0 +1,24 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using Squidex.Domain.Apps.Core.Schemas;
+
+namespace Squidex.Domain.Apps.Events.Schemas
+{
+    public sealed class SchemaCreatedNestedField
+    {
+        public string Name { get; set; }
+
+        public bool IsHidden { get; set; }
+
+        public bool IsLocked { get; set; }
+
+        public bool IsDisabled { get; set; }
+
+        public FieldProperties Properties { get; set; }
+    }
+}

src/Squidex.Domain.Apps.Events/Schemas/SchemaFieldsReordered.cs

@@ -6,6 +6,7 @@
 // ==========================================================================
 
 using System.Collections.Generic;
+using Squidex.Infrastructure;
 using Squidex.Infrastructure.EventSourcing;
 
 namespace Squidex.Domain.Apps.Events.Schemas
@@ -13,6 +14,8 @@ namespace Squidex.Domain.Apps.Events.Schemas
     [EventType(nameof(SchemaFieldsReordered))]
     public sealed class SchemaFieldsReordered : SchemaEvent
     {
+        public NamedId<long> ParentFieldIdId { get; set; }
+
         public List<long> FieldIds { get; set; }
     }
 }

tests/Squidex.Domain.Apps.Core.Tests/TestData.cs

@@ -54,49 +54,44 @@ namespace Squidex.Domain.Apps.Core
 
         public static Schema MixedSchema()
         {
-            var inv = Partitioning.Invariant;
-
-            var schema = new Schema("user");
-
-            schema = schema.Publish();
-            schema = schema.Update(new SchemaProperties { Hints = "The User" });
-
-            schema = schema.AddJson(1, "my-json", inv,
-                new JsonFieldProperties());
-
-            schema = schema.AddAssets(2, "my-assets", inv,
-                new AssetsFieldProperties());
-
-            schema = schema.AddString(3, "my-string1", inv,
-                new StringFieldProperties { Label = "My String1", IsRequired = true, AllowedValues = ImmutableList.Create("a", "b") });
-
-            schema = schema.AddString(4, "my-string2", inv,
-                new StringFieldProperties { Hints = "My String1" });
-
-            schema = schema.AddNumber(5, "my-number", inv,
-                new NumberFieldProperties { MinValue = 1, MaxValue = 10 });
-
-            schema = schema.AddBoolean(6, "my-boolean", inv,
-                new BooleanFieldProperties());
-
-            schema = schema.AddDateTime(7, "my-datetime", inv,
-                new DateTimeFieldProperties { Editor = DateTimeFieldEditor.DateTime });
-
-            schema = schema.AddDateTime(8, "my-date", inv,
-                new DateTimeFieldProperties { Editor = DateTimeFieldEditor.Date });
-
-            schema = schema.AddGeolocation(9, "my-geolocation", inv,
-                new GeolocationFieldProperties());
-
-            schema = schema.AddReferences(10, "my-references", inv,
-                new ReferencesFieldProperties());
-
-            schema = schema.AddTags(11, "my-tags", Partitioning.Language,
-                new TagsFieldProperties());
-
-            schema = schema.UpdateField(7, f => f.Hide());
-            schema = schema.UpdateField(8, f => f.Lock());
-            schema = schema.UpdateField(9, f => f.Disable());
+            var schema = new Schema("user")
+                .Publish()
+                .AddArray(101, "root-array", Partitioning.Language, f => f
+                    .AddAssets(201, "nested-assets")
+                    .AddBoolean(202, "nested-boolean")
+                    .AddDateTime(203, "nested-datetime")
+                    .AddGeolocation(204, "nested-geolocation")
+                    .AddJson(205, "nested-json")
+                    .AddNumber(206, "nested-number")
+                    .AddReferences(207, "nested-references")
+                    .AddString(208, "nested-string")
+                    .AddTags(209, "nested-tags"))
+                .AddAssets(102, "root-assets", Partitioning.Invariant,
+                    new AssetsFieldProperties())
+                .AddBoolean(103, "root-boolean", Partitioning.Invariant,
+                    new BooleanFieldProperties())
+                .AddDateTime(104, "root-datetime", Partitioning.Invariant,
+                    new DateTimeFieldProperties { Editor = DateTimeFieldEditor.DateTime })
+                .AddDateTime(105, "root-date", Partitioning.Invariant,
+                    new DateTimeFieldProperties { Editor = DateTimeFieldEditor.Date })
+                .AddGeolocation(106, "root-geolocation", Partitioning.Invariant,
+                    new GeolocationFieldProperties())
+                .AddJson(107, "root-json", Partitioning.Invariant,
+                    new JsonFieldProperties())
+                .AddNumber(108, "root-number", Partitioning.Invariant,
+                    new NumberFieldProperties { MinValue = 1, MaxValue = 10 })
+                .AddReferences(109, "root-references", Partitioning.Invariant,
+                    new ReferencesFieldProperties())
+                .AddString(110, "root-string1", Partitioning.Invariant,
+                    new StringFieldProperties { Label = "My String1", IsRequired = true, AllowedValues = ImmutableList.Create("a", "b") })
+                .AddString(111, "root-string2", Partitioning.Invariant,
+                    new StringFieldProperties { Hints = "My String1" })
+                .AddTags(112, "root-tags", Partitioning.Language,
+                    new TagsFieldProperties())
+                .Update(new SchemaProperties { Hints = "The User" })
+                .UpdateField(107, f => f.Hide())
+                .UpdateField(108, f => f.Lock())
+                .UpdateField(109, f => f.Disable());
 
             return schema;
         }