Improve field.

backend/src/Squidex.Domain.Apps.Entities.MongoDb/Assets/MongoAssetFolderRepository.cs

@@ -66,7 +66,9 @@ namespace Squidex.Domain.Apps.Entities.MongoDb.Assets
                     await Collection.Find(filter).Only(x => x.Id)
                         .ToListAsync();
 
-                return assetFolderEntities.Select(x => DomainId.Create(x[Fields.AssetFolderId].AsString)).ToList();
+                var field = Field.Of<MongoAssetFolderEntity>(x => nameof(x.Id));
+
+                return assetFolderEntities.Select(x => DomainId.Create(x[field].AsString)).ToList();
             }
         }
 

backend/src/Squidex.Domain.Apps.Entities.MongoDb/Assets/MongoAssetRepository.cs

@@ -141,7 +141,9 @@ namespace Squidex.Domain.Apps.Entities.MongoDb.Assets
                     await Collection.Find(BuildFilter(appId, ids)).Only(x => x.Id)
                         .ToListAsync();
 
-                return assetEntities.Select(x => DomainId.Create(x[Fields.AssetId].AsString)).ToList();
+                var field = Field.Of<MongoAssetFolderEntity>(x => nameof(x.Id));
+
+                return assetEntities.Select(x => DomainId.Create(x[field].AsString)).ToList();
             }
         }
 
@@ -153,7 +155,9 @@ namespace Squidex.Domain.Apps.Entities.MongoDb.Assets
                     await Collection.Find(x => x.IndexedAppId == appId && !x.IsDeleted && x.ParentId == parentId).Only(x => x.Id)
                         .ToListAsync();
 
-                return assetEntities.Select(x => DomainId.Create(x[Fields.AssetId].AsString)).ToList();
+                var field = Field.Of<MongoAssetFolderEntity>(x => nameof(x.Id));
+
+                return assetEntities.Select(x => DomainId.Create(x[field].AsString)).ToList();
             }
         }
 

backend/src/Squidex.Domain.Apps.Entities.MongoDb/FullText/MongoTextIndex.cs

@@ -132,10 +132,12 @@ namespace Squidex.Domain.Apps.Entities.MongoDb.FullText
                         Filter.In(x => x.SchemaId, filter.SchemaIds),
                         Filter_ByScope(scope),
                         Filter.Text(queryText, "none")))
-                    .Only(x => x.ContentId).Limit(limit)
+                    .Limit(limit).Only(x => x.ContentId)
                     .ToListAsync();
 
-            return bySchema.Select(x => DomainId.Create(x["_ci"].AsString)).Distinct().ToList();
+            var field = Field.Of<MongoTextIndexEntity>(x => nameof(x.ContentId));
+
+            return bySchema.Select(x => DomainId.Create(x[field].AsString)).Distinct().ToList();
         }
 
         private async Task<List<DomainId>> SearchByAppAsync(string queryText, IAppEntity app, SearchScope scope, int limit)
@@ -147,10 +149,12 @@ namespace Squidex.Domain.Apps.Entities.MongoDb.FullText
                         Filter.Exists(x => x.SchemaId),
                         Filter_ByScope(scope),
                         Filter.Text(queryText, "none")))
-                    .Only(x => x.ContentId).Limit(limit)
+                    .Limit(limit).Only(x => x.ContentId)
                     .ToListAsync();
 
-            return bySchema.Select(x => DomainId.Create(x["_ci"].AsString)).Distinct().ToList();
+            var field = Field.Of<MongoTextIndexEntity>(x => nameof(x.ContentId));
+
+            return bySchema.Select(x => DomainId.Create(x[field].AsString)).Distinct().ToList();
         }
 
         private static FilterDefinition<MongoTextIndexEntity> Filter_ByScope(SearchScope scope)

backend/src/Squidex.Infrastructure.MongoDb/MongoDb/Field.cs

@@ -0,0 +1,22 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using MongoDB.Bson.Serialization;
+
+namespace Squidex.Infrastructure.MongoDb
+{
+    public static class Field
+    {
+        public static string Of<T>(Func<T, string> mapper)
+        {
+            var name = mapper(default!);
+
+            return BsonClassMap.LookupClassMap(typeof(T)).GetMemberMap(name).ElementName;
+        }
+    }
+}

backend/src/Squidex.Infrastructure.MongoDb/MongoDb/MongoExtensions.cs

@@ -120,9 +120,9 @@ namespace Squidex.Infrastructure.MongoDb
 
                 if (existingVersion != null)
                 {
-                    var versionField = GetVersionField<T, TKey>();
+                    var field = Field.Of<T>(x => nameof(x.Version));
 
-                    throw new InconsistentStateException(existingVersion[versionField].AsInt64, oldVersion, ex);
+                    throw new InconsistentStateException(existingVersion[field].AsInt64, oldVersion, ex);
                 }
                 else
                 {
@@ -156,9 +156,9 @@ namespace Squidex.Infrastructure.MongoDb
 
                 if (existingVersion != null)
                 {
-                    var versionField = GetVersionField<T, TKey>();
+                    var field = Field.Of<T>(x => nameof(x.Version));
 
-                    throw new InconsistentStateException(existingVersion[versionField].AsInt64, oldVersion, ex);
+                    throw new InconsistentStateException(existingVersion[field].AsInt64, oldVersion, ex);
                 }
                 else
                 {
@@ -167,12 +167,6 @@ namespace Squidex.Infrastructure.MongoDb
             }
         }
 
-        private static string GetVersionField<T, TKey>()
-            where T : IVersionedEntity<TKey> where TKey : notnull
-        {
-            return BsonClassMap.LookupClassMap(typeof(T)).GetMemberMap(nameof(IVersionedEntity<TKey>.Version)).ElementName;
-        }
-
         public static async Task ForEachPipedAsync<T>(this IAsyncCursorSource<T> source, Func<T, Task> processor, CancellationToken cancellationToken = default)
         {
             using (var cursor = await source.ToCursorAsync(cancellationToken))

backend/tests/Squidex.Infrastructure.Tests/MongoDb/FieldTests.cs

@@ -0,0 +1,49 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using MongoDB.Bson.Serialization.Attributes;
+using Xunit;
+
+namespace Squidex.Infrastructure.MongoDb
+{
+    public class FieldTests
+    {
+        public sealed class Entity
+        {
+            public string Id { get; set; }
+
+            public string Default { get; set; }
+
+            [BsonElement("_c")]
+            public string Custom { get; set; }
+        }
+
+        [Fact]
+        public void Should_resolve_id_field()
+        {
+            var name = Field.Of<Entity>(x => nameof(x.Id));
+
+            Assert.Equal("_id", name);
+        }
+
+        [Fact]
+        public void Should_resolve_default_field()
+        {
+            var name = Field.Of<Entity>(x => nameof(x.Default));
+
+            Assert.Equal("Default", name);
+        }
+
+        [Fact]
+        public void Should_resolve_custom_field()
+        {
+            var name = Field.Of<Entity>(x => nameof(x.Custom));
+
+            Assert.Equal("_c", name);
+        }
+    }
+}