From c20fe4ac17e7cbd7f826fbb37fa78911e65d3bc3 Mon Sep 17 00:00:00 2001
From: John Estropia <rommel.estropia@gmail.com>
Date: Wed, 5 Feb 2020 11:03:57 +0900
Subject: [PATCH] add Field.Relationship dynamicMemberLookups

---
 Sources/FIeldRelationshipType.swift | 42 +++++++++++++++++++++++++++++
 Sources/ObjectPublisher.swift       | 18 +++++++++++++
 Sources/ObjectSnapshot.swift        | 19 +++++++++++++
 3 files changed, 79 insertions(+)

diff --git a/Sources/FIeldRelationshipType.swift b/Sources/FIeldRelationshipType.swift
index f054adc..b19e751 100644
--- a/Sources/FIeldRelationshipType.swift
+++ b/Sources/FIeldRelationshipType.swift
@@ -37,10 +37,16 @@ public protocol FieldRelationshipType {
 
     associatedtype SnapshotValueType
 
+    associatedtype PublishedType
+
     static func cs_toReturnType(from value: NativeValueType?) -> Self
 
+    static func cs_toPublishedType(from value: SnapshotValueType, in context: NSManagedObjectContext) -> PublishedType
+
     static func cs_toNativeType(from value: Self) -> NativeValueType?
 
+    static func cs_toSnapshotType(from value: PublishedType) -> SnapshotValueType
+
     static func cs_valueForSnapshot(from value: NativeValueType?) -> SnapshotValueType
 }
 
@@ -60,16 +66,28 @@ extension Optional: FieldRelationshipType, FieldRelationshipToOneType where Wrap
 
     public typealias SnapshotValueType = NSManagedObjectID?
 
+    public typealias PublishedType = ObjectPublisher<DestinationObjectType>?
+
     public static func cs_toReturnType(from value: NativeValueType?) -> Self {
 
         return value.map(Wrapped.cs_fromRaw(object:))
     }
 
+    public static func cs_toPublishedType(from value: SnapshotValueType, in context: NSManagedObjectContext) -> PublishedType {
+
+        return value.map(context.objectPublisher(objectID:))
+    }
+
     public static func cs_toNativeType(from value: Self) -> NativeValueType? {
 
         return value?.cs_toRaw()
     }
 
+    public static func cs_toSnapshotType(from value: PublishedType) -> SnapshotValueType {
+
+        return value?.objectID()
+    }
+
     public static func cs_valueForSnapshot(from value: NativeValueType?) -> SnapshotValueType {
 
         return value?.objectID
@@ -85,6 +103,8 @@ extension Array: FieldRelationshipType, FieldRelationshipToManyType, FieldRelati
 
     public typealias SnapshotValueType = [NSManagedObjectID]
 
+    public typealias PublishedType = [ObjectPublisher<DestinationObjectType>]
+
     public static func cs_toReturnType(from value: NativeValueType?) -> Self {
 
         guard let value = value else {
@@ -94,11 +114,21 @@ extension Array: FieldRelationshipType, FieldRelationshipToManyType, FieldRelati
         return value.map({ Element.cs_fromRaw(object: $0 as! NSManagedObject) })
     }
 
+    public static func cs_toPublishedType(from value: SnapshotValueType, in context: NSManagedObjectContext) -> PublishedType {
+
+        return value.map(context.objectPublisher(objectID:))
+    }
+
     public static func cs_toNativeType(from value: Self) -> NativeValueType? {
 
         return NSOrderedSet(array: value.map({ $0.rawObject! }))
     }
 
+    public static func cs_toSnapshotType(from value: PublishedType) -> SnapshotValueType {
+
+        return value.map({ $0.objectID() })
+    }
+
     public static func cs_valueForSnapshot(from value: NativeValueType?) -> SnapshotValueType {
 
         guard let value = value else {
@@ -117,6 +147,8 @@ extension Set: FieldRelationshipType, FieldRelationshipToManyType, FieldRelation
 
     public typealias SnapshotValueType = Set<NSManagedObjectID>
 
+    public typealias PublishedType = Set<ObjectPublisher<DestinationObjectType>>
+
     public static func cs_toReturnType(from value: NativeValueType?) -> Self {
 
         guard let value = value else {
@@ -126,11 +158,21 @@ extension Set: FieldRelationshipType, FieldRelationshipToManyType, FieldRelation
         return Set(value.map({ Element.cs_fromRaw(object: $0 as! NSManagedObject) }))
     }
 
+    public static func cs_toPublishedType(from value: SnapshotValueType, in context: NSManagedObjectContext) -> PublishedType {
+
+        return PublishedType(value.map(context.objectPublisher(objectID:)))
+    }
+
     public static func cs_toNativeType(from value: Self) -> NativeValueType? {
 
         return NSSet(array: value.map({ $0.rawObject! }))
     }
 
+    public static func cs_toSnapshotType(from value: PublishedType) -> SnapshotValueType {
+
+        return SnapshotValueType(value.map({ $0.objectID() }))
+    }
+
     public static func cs_valueForSnapshot(from value: NativeValueType?) -> SnapshotValueType {
 
         guard let value = value else {
diff --git a/Sources/ObjectPublisher.swift b/Sources/ObjectPublisher.swift
index 5426925..9549851 100644
--- a/Sources/ObjectPublisher.swift
+++ b/Sources/ObjectPublisher.swift
@@ -397,6 +397,24 @@ extension ObjectPublisher where O: CoreStoreObject {
         return FieldContainer<OBase>.Computed<V>.read(field: object[keyPath: member], for: rawObject) as! V?
     }
 
+    /**
+     Returns the value for the property identified by a given key.
+     */
+    public subscript<OBase, V>(dynamicMember member: KeyPath<O, FieldContainer<OBase>.Relationship<V>>) -> V.PublishedType? {
+
+        guard
+            let object = self.object,
+            let rawObject = object.rawObject,
+            let value = FieldContainer<OBase>.Relationship<V>.read(field: object[keyPath: member], for: rawObject) as! V?
+            else {
+
+                return nil
+        }
+        let nativeValue = V.cs_toNativeType(from: value)
+        let snapshotValue = V.cs_valueForSnapshot(from: nativeValue)
+        return V.cs_toPublishedType(from: snapshotValue, in: self.context)
+     }
+
     /**
      Returns the value for the property identified by a given key.
      */
diff --git a/Sources/ObjectSnapshot.swift b/Sources/ObjectSnapshot.swift
index 0845636..cfac82d 100644
--- a/Sources/ObjectSnapshot.swift
+++ b/Sources/ObjectSnapshot.swift
@@ -209,6 +209,25 @@ extension ObjectSnapshot where O: CoreStoreObject {
         }
     }
 
+    /**
+     Returns the value for the property identified by a given key.
+     */
+    public subscript<OBase, V>(dynamicMember member: KeyPath<O, FieldContainer<OBase>.Relationship<V>>) -> V.PublishedType {
+
+        get {
+
+            let key = String(keyPath: member)
+            let context = self.context
+            let snapshotValue = self.values[key] as! V.SnapshotValueType
+            return V.cs_toPublishedType(from: snapshotValue, in: context)
+        }
+        set {
+
+            let key = String(keyPath: member)
+            self.values[key] = V.cs_toSnapshotType(from: newValue)
+        }
+    }
+
     /**
      Returns the value for the property identified by a given key.
      */