Fixing one to one relation null's serialization

Kyoo.Common/Controllers/Implementations/LibraryManager.cs

@@ -306,10 +306,13 @@ namespace Kyoo.Controllers
 				(Show s, nameof(Show.Collections)) => CollectionRepository
 					.GetAll(x => x.Shows.Any(y => y.ID == obj.ID))
 					.Then(x => s.Collections = x),
-				// TODO Studio loading does not work.
 				(Show s, nameof(Show.Studio)) => StudioRepository
 					.Get(x => x.Shows.Any(y => y.ID == obj.ID))
-					.Then(x => s.Studio = x),
+					.Then(x =>
+					{
+						s.Studio = x;
+						s.StudioID = x?.ID ?? 0;
+					}),
 				
 				(Season s, nameof(Season.ExternalIDs)) => ProviderRepository
 					.GetMetadataID(x => x.SeasonID == obj.ID)
@@ -319,7 +322,11 @@ namespace Kyoo.Controllers
 					.Then(x => s.Episodes = x),
 				(Season s, nameof(Season.Show)) => ShowRepository
 					.Get(x => x.Seasons.Any(y => y.ID == obj.ID))
-					.Then(x => s.Show = x),
+					.Then(x =>
+					{
+						s.Show = x;
+						s.ShowID = x?.ID ?? 0;
+					}),
 				
 				(Episode e, nameof(Episode.ExternalIDs)) => ProviderRepository
 					.GetMetadataID(x => x.EpisodeID == obj.ID)
@@ -329,14 +336,26 @@ namespace Kyoo.Controllers
 					.Then(x => e.Tracks = x),
 				(Episode e, nameof(Episode.Show)) => ShowRepository
 					.Get(x => x.Episodes.Any(y => y.ID == obj.ID))
-					.Then(x => e.Show = x),
+					.Then(x =>
+					{
+						e.Show = x;
+						e.ShowID = x?.ID ?? 0;
+					}),
 				(Episode e, nameof(Episode.Season)) => SeasonRepository
 					.Get(x => x.Episodes.Any(y => y.ID == e.ID))
-					.Then(x => e.Season = x),
+					.Then(x =>
+					{
+						e.Season = x;
+						e.SeasonID = x?.ID ?? 0;
+					}),
 				
 				(Track t, nameof(Track.Episode)) => EpisodeRepository
 					.Get(x => x.Tracks.Any(y => y.ID == obj.ID))
-					.Then(x => t.Episode = x),
+					.Then(x =>
+					{
+						t.Episode = x;
+						t.EpisodeID = x?.ID ?? 0;
+					}),
 				
 				(Genre g, nameof(Genre.Shows)) => ShowRepository
 					.GetAll(x => x.Genres.Any(y => y.ID == obj.ID))

Kyoo.Common/Models/Attributes/RelationAttributes.cs

@@ -4,7 +4,17 @@ namespace Kyoo.Models.Attributes
 {
 	[AttributeUsage(AttributeTargets.Property, Inherited = false)]
 	public class EditableRelationAttribute : Attribute { }
-	
+
 	[AttributeUsage(AttributeTargets.Property)]
-	public class LoadableRelationAttribute : Attribute { }
+	public class LoadableRelationAttribute : Attribute
+	{
+		public string RelationID { get; }
+		
+		public LoadableRelationAttribute() {}
+
+		public LoadableRelationAttribute(string relationID)
+		{
+			RelationID = relationID;
+		}
+	}
 }

Kyoo.Common/Models/Resources/Episode.cs

@@ -10,10 +10,10 @@ namespace Kyoo.Models
 	{
 		public int ID { get; set; }
 		public string Slug => Show != null ? GetSlug(Show.Slug, SeasonNumber, EpisodeNumber) : ID.ToString();
-		public int ShowID { get; set; }
+		[SerializeIgnore] public int ShowID { get; set; }
-		[LoadableRelation] public virtual Show Show { get; set; }
+		[LoadableRelation(nameof(ShowID))] public virtual Show Show { get; set; }
-		public int? SeasonID { get; set; }
+		[SerializeIgnore] public int? SeasonID { get; set; }
-		[LoadableRelation] public virtual Season Season { get; set; }
+		[LoadableRelation(nameof(SeasonID))] public virtual Season Season { get; set; }
 
 		public int SeasonNumber { get; set; } = -1;
 		public int EpisodeNumber { get; set; } = -1;

Kyoo.Common/Models/Resources/Season.cs

@@ -8,7 +8,7 @@ namespace Kyoo.Models
 	public class Season : IResource
 	{
 		public int ID  { get; set; }
-		public int ShowID { get; set; }
+		[SerializeIgnore] public int ShowID { get; set; }
 
 		public int SeasonNumber { get; set; } = -1;
 
@@ -21,7 +21,7 @@ namespace Kyoo.Models
 		public string Thumb => $"/api/seasons/{Slug}/thumb";
 		[EditableRelation] [LoadableRelation] public virtual ICollection<MetadataID> ExternalIDs { get; set; }
 
-		[LoadableRelation] public virtual Show Show { get; set; }
+		[LoadableRelation(nameof(ShowID))] public virtual Show Show { get; set; }
 		[LoadableRelation] public virtual ICollection<Episode> Episodes { get; set; }
 
 		public Season() { }

Kyoo.Common/Models/Resources/Show.cs

@@ -28,7 +28,7 @@ namespace Kyoo.Models
 		
 		
 		[SerializeIgnore] public int? StudioID { get; set; }
-		[LoadableRelation] [EditableRelation] public virtual Studio Studio { get; set; }
+		[LoadableRelation(nameof(StudioID))] [EditableRelation] public virtual Studio Studio { get; set; }
 		[LoadableRelation] [EditableRelation] public virtual ICollection<Genre> Genres { get; set; }
 		[LoadableRelation] [EditableRelation] public virtual ICollection<PeopleRole> People { get; set; }
 		[LoadableRelation] public virtual ICollection<Season> Seasons { get; set; }

Kyoo.Common/Models/Resources/Track.cs

@@ -57,7 +57,7 @@ namespace Kyoo.Models
 	public class Track : Stream, IResource
 	{
 		public int ID { get; set; }
-		public int EpisodeID { get; set; }
+		[SerializeIgnore] public int EpisodeID { get; set; }
 		public bool IsDefault
 		{
 			get => isDefault;
@@ -114,11 +114,18 @@ namespace Kyoo.Models
 		}
 
 		public bool IsExternal { get; set; }
-		[LoadableRelation] public virtual Episode Episode { get; set; }
+		[LoadableRelation(nameof(EpisodeID))] public virtual Episode Episode { get; set; }
 		
 		public Track() { }
 
-		public Track(StreamType type, string title, string language, bool isDefault, bool isForced, string codec, bool isExternal, string path)
+		public Track(StreamType type, 
+			string title, 
+			string language, 
+			bool isDefault,
+			bool isForced,
+			string codec, 
+			bool isExternal, 
+			string path)
 			: base(title, language, codec, isDefault, isForced, path, type)
 		{
 			IsExternal = isExternal;

Kyoo.Common/Utility.cs

@@ -33,6 +33,20 @@ namespace Kyoo
 				: ex.Body as MemberExpression;
 			return member!.Member.Name;
 		}
+
+		public static object GetValue([NotNull] this MemberInfo member, [NotNull] object obj)
+		{
+			if (member == null)
+				throw new ArgumentNullException(nameof(member));
+			if (obj == null)
+				throw new ArgumentNullException(nameof(obj));
+			return member switch
+			{
+				PropertyInfo property => property.GetValue(obj),
+				FieldInfo field => field.GetValue(obj),
+				_ => throw new ArgumentException($"Can't get value of a non property/field (member: {member}).")
+			};
+		}
 		
 		public static string ToSlug(string str)
 		{

Kyoo.CommonAPI/JsonSerializer.cs

@@ -10,9 +10,21 @@ namespace Kyoo.Controllers
 		protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
 		{
 			JsonProperty property = base.CreateProperty(member, memberSerialization);
-			
+
-			if (member?.GetCustomAttribute<LoadableRelationAttribute>() != null)
+			LoadableRelationAttribute relation = member?.GetCustomAttribute<LoadableRelationAttribute>();
-				property.NullValueHandling = NullValueHandling.Ignore;
+			if (relation != null)
+			{
+				if (relation.RelationID == null)
+					property.ShouldSerialize = x => member.GetValue(x) != null;
+				else
+					property.ShouldSerialize = x =>
+					{
+						if (member.GetValue(x) != null)
+							return true;
+						return x.GetType().GetProperty(relation.RelationID)?.GetValue(x) != null;
+					};
+			}
+
 			if (member?.GetCustomAttribute<SerializeIgnoreAttribute>() != null)
 				property.ShouldSerialize = _ => false;
 			if (member?.GetCustomAttribute<DeserializeIgnoreAttribute>() != null)

Kyoo.CommonAPI/ResourceViewAttribute.cs

@@ -75,7 +75,6 @@ namespace Kyoo.CommonApi
 			Type pageType = Utility.GetGenericDefinition(result.DeclaredType, typeof(Page<>));
 
 			
-			// TODO loading is case sensitive. Maybe convert them in the first check.
 			if (pageType != null)
 			{
 				foreach (IResource resource in ((dynamic)result.Value).Items)