Revert "Restore results controller and add transformed options"

This reverts commit 7e65cbb.

Author: itsmeichigo

Modules/Sources/Yosemite/Tools/ResultsController.swift

@@ -2,14 +2,16 @@ import Foundation
 import Storage
 import CoreData
 
+
+
 // MARK: - MutableType: Storage.framework Type that will be retrieved (and converted into ReadOnly)
 //
 public typealias ResultsControllerMutableType = NSManagedObject & ReadOnlyConvertible
 
 
-// MARK: - ResultsController
+// MARK: - GenericResultsController (Core Implementation)
 //
-public class ResultsController<T: ResultsControllerMutableType> {
+public class GenericResultsController<T: ResultsControllerMutableType, Output> {
 
     /// The `StorageType` used to fetch objects.
     ///
@@ -77,7 +79,7 @@ public class ResultsController<T: ResultsControllerMutableType> {
 
     /// Closure to be executed whenever an Object is updated.
     ///
-    public var onDidChangeObject: ((_ object: T.ReadOnlyType, _ indexPath: IndexPath?, _ type: ChangeType, _ newIndexPath: IndexPath?) -> Void)?
+    public var onDidChangeObject: ((_ object: Output, _ indexPath: IndexPath?, _ type: ChangeType, _ newIndexPath: IndexPath?) -> Void)?
 
     /// Closure to be executed whenever an entire Section is updated.
     ///
@@ -92,19 +94,25 @@ public class ResultsController<T: ResultsControllerMutableType> {
     ///
     private let fetchLimit: Int?
 
+    /// Transformer closure to convert T to Output type.
+    ///
+    private let transformer: (T) -> Output
+
     /// Designated Initializer.
     ///
     public init(viewStorage: StorageType,
                 sectionNameKeyPath: String? = nil,
                 matching predicate: NSPredicate? = nil,
                 fetchLimit: Int? = nil,
-                sortedBy descriptors: [NSSortDescriptor]) {
+                sortedBy descriptors: [NSSortDescriptor],
+                transformer: @escaping (T) -> Output) {
 
         self.viewStorage = viewStorage
         self.sectionNameKeyPath = sectionNameKeyPath
         self.predicate = predicate
         self.fetchLimit = fetchLimit
         self.sortDescriptors = descriptors
+        self.transformer = transformer
 
         setupResultsController()
         setupEventsForwarding()
@@ -117,13 +125,15 @@ public class ResultsController<T: ResultsControllerMutableType> {
                             sectionNameKeyPath: String? = nil,
                             matching predicate: NSPredicate? = nil,
                             fetchLimit: Int? = nil,
-                            sortedBy descriptors: [NSSortDescriptor]) {
+                            sortedBy descriptors: [NSSortDescriptor],
+                            transformer: @escaping (T) -> Output) {
 
         self.init(viewStorage: storageManager.viewStorage,
                   sectionNameKeyPath: sectionNameKeyPath,
                   matching: predicate,
                   fetchLimit: fetchLimit,
-                  sortedBy: descriptors)
+                  sortedBy: descriptors,
+                  transformer: transformer)
     }
 
 
@@ -137,14 +147,14 @@ public class ResultsController<T: ResultsControllerMutableType> {
     ///
     /// Prefer to use `safeObject(at:)` instead.
     ///
-    public func object(at indexPath: IndexPath) -> T.ReadOnlyType {
-        return controller.object(at: indexPath).toReadOnly()
+    public func object(at indexPath: IndexPath) -> Output {
+        return transformer(controller.object(at: indexPath))
     }
 
     /// Returns the fetched object at the given `indexPath`. Returns `nil` if the `indexPath`
     /// does not exist.
     ///
-    public func safeObject(at indexPath: IndexPath) -> T.ReadOnlyType? {
+    public func safeObject(at indexPath: IndexPath) -> Output? {
         guard !isEmpty else {
             return nil
         }
@@ -158,7 +168,7 @@ public class ResultsController<T: ResultsControllerMutableType> {
             return nil
         }
 
-        return controller.object(at: indexPath).toReadOnly()
+        return transformer(controller.object(at: indexPath))
     }
 
     /// Returns the Plain ObjectIndex corresponding to a given IndexPath. You can use this index to map the
@@ -179,21 +189,6 @@ public class ResultsController<T: ResultsControllerMutableType> {
         return output
     }
 
-    /// Returns an array of all of the transformed fetched objects.
-    /// Note: Avoid calling this in computed variables as the conversion of storage items can be costly.
-    ///
-    public func transformedObjects<U>(using transformation: (T) -> U) -> [U] {
-        controller.fetchedObjects?.compactMap { mutableObject in
-            transformation(mutableObject)
-        } ?? []
-    }
-
-    /// Returns a transformed object at a given index
-    ///
-    public func transformedObject<U>(at indexPath: IndexPath, using transformation: (T) -> U) -> U {
-        transformation(controller.object(at: indexPath))
-    }
-
     /// Indicates if there are any Objects matching the specified criteria.
     ///
     public var isEmpty: Bool {
@@ -209,22 +204,22 @@ public class ResultsController<T: ResultsControllerMutableType> {
     /// Returns an array of all of the (ReadOnly) Fetched Objects.
     /// Note: Avoid calling this in computed variables as the conversion of storage items can be costly.
     ///
-    public var fetchedObjects: [T.ReadOnlyType] {
-        let readOnlyObjects = controller.fetchedObjects?.compactMap { mutableObject in
-            mutableObject.toReadOnly()
+    public var fetchedObjects: [Output] {
+        let transformedObjects = controller.fetchedObjects?.compactMap { mutableObject in
+            transformer(mutableObject)
         }
 
-        return readOnlyObjects ?? []
+        return transformedObjects ?? []
     }
 
     /// Returns an array of SectionInfo Entitites.
     ///
     public var sections: [SectionInfo] {
-        let readOnlySections = controller.sections?.compactMap { mutableSection in
-            SectionInfo(mutableSection: mutableSection)
+        let transformedSections = controller.sections?.compactMap { mutableSection in
+            SectionInfo(mutableSection: mutableSection, transformer: transformer)
         }
 
-        return readOnlySections ?? []
+        return transformedSections ?? []
     }
 
     /// Returns an optional index path of the first matching object.
@@ -274,17 +269,17 @@ public class ResultsController<T: ResultsControllerMutableType> {
                 return
             }
 
-            let readOnlyObject = object.toReadOnly()
-            self.onDidChangeObject?(readOnlyObject, indexPath, type, newIndexPath)
+            let transformedObject = transformer(object)
+            self.onDidChangeObject?(transformedObject, indexPath, type, newIndexPath)
         }
 
         internalDelegate.onDidChangeSection = { [weak self] (mutableSection, sectionIndex, type) in
             guard let `self` = self else {
                 return
             }
 
-            let readOnlySection = SectionInfo(mutableSection: mutableSection)
-            self.onDidChangeSection?(readOnlySection, sectionIndex, type)
+            let transformedSection = SectionInfo(mutableSection: mutableSection, transformer: transformer)
+            self.onDidChangeSection?(transformedSection, sectionIndex, type)
         }
     }
 
@@ -308,7 +303,7 @@ public class ResultsController<T: ResultsControllerMutableType> {
 
 // MARK: - Nested Types
 //
-public extension ResultsController {
+public extension GenericResultsController {
 
     // MARK: - ResultsController.ChangeType
     //
@@ -336,9 +331,13 @@ public extension ResultsController {
             mutableSectionInfo.numberOfObjects
         }
 
-        /// Returns the array of (ReadOnly) objects in the section.
+        /// Transformer closure to convert objects in the section.
+        ///
+        private let transformer: (T) -> Output
+
+        /// Returns the array of transformed objects in the section.
         ///
-        private(set) public lazy var objects: [T.ReadOnlyType] = {
+        private(set) public lazy var objects: [Output] = {
             guard let objects = mutableSectionInfo.objects else {
                 return []
             }
@@ -347,13 +346,47 @@ public extension ResultsController {
                 return []
             }
 
-            return castedObjects.map { $0.toReadOnly() }
+            return castedObjects.map { transformer($0) }
         }()
 
         /// Designated Initializer
         ///
-        init(mutableSection: NSFetchedResultsSectionInfo) {
+        init(mutableSection: NSFetchedResultsSectionInfo, transformer: @escaping (T) -> Output) {
             mutableSectionInfo = mutableSection
+            self.transformer = transformer
         }
     }
 }
+
+// MARK: - ResultsController (Backward Compatible Specialization)
+//
+public class ResultsController<T: ResultsControllerMutableType>: GenericResultsController<T, T.ReadOnlyType> {
+    /// Designated Initializer.
+    ///
+    public init(viewStorage: StorageType,
+                sectionNameKeyPath: String? = nil,
+                matching predicate: NSPredicate? = nil,
+                fetchLimit: Int? = nil,
+                sortedBy descriptors: [NSSortDescriptor]) {
+        super.init(viewStorage: viewStorage,
+                   sectionNameKeyPath: sectionNameKeyPath,
+                   matching: predicate,
+                   fetchLimit: fetchLimit,
+                   sortedBy: descriptors,
+                   transformer: { $0.toReadOnly() })
+    }
+
+    /// Convenience Initializer.
+    ///
+    public convenience init(storageManager: StorageManagerType,
+                            sectionNameKeyPath: String? = nil,
+                            matching predicate: NSPredicate? = nil,
+                            fetchLimit: Int? = nil,
+                            sortedBy descriptors: [NSSortDescriptor]) {
+        self.init(viewStorage: storageManager.viewStorage,
+                  sectionNameKeyPath: sectionNameKeyPath,
+                  matching: predicate,
+                  fetchLimit: fetchLimit,
+                  sortedBy: descriptors)
+    }
+}

WooCommerce/Classes/ViewModels/Order Details/OrderDetailsResultsControllers.swift

@@ -23,7 +23,7 @@ final class OrderDetailsResultsControllers {
 
     /// Product ResultsController.
     ///
-    private lazy var productResultsController: ResultsController<StorageProduct> = createProductResultsController()
+    private lazy var productResultsController: GenericResultsController<StorageProduct, OrderDetailsProduct> = createProductResultsController()
 
     /// ProductVariation ResultsController.
     ///
@@ -245,12 +245,9 @@ private extension OrderDetailsResultsControllers {
     }
 
     private func configureProductResultsController(onReload: @escaping () -> Void) {
-        let transformationHandler: (StorageProduct) -> OrderDetailsProduct = {
-            OrderDetailsProduct(storageProduct: $0)
-        }
         productResultsController.onDidChangeContent = { [weak self] in
             guard let self else { return }
-            products = productResultsController.transformedObjects(using: transformationHandler)
+            products = productResultsController.fetchedObjects
             onReload()
         }
 
@@ -264,7 +261,7 @@ private extension OrderDetailsResultsControllers {
 
         do {
             try productResultsController.performFetch()
-            products = productResultsController.transformedObjects(using: transformationHandler)
+            products = productResultsController.fetchedObjects
         } catch {
             DDLogError("⛔️ Unable to fetch Products for Site \(siteID): \(error)")
         }
@@ -377,15 +374,16 @@ private extension OrderDetailsResultsControllers {
         try? shippingMethodsResultsController.performFetch()
     }
 
-    func createProductResultsController() -> ResultsController<StorageProduct> {
+    func createProductResultsController() -> GenericResultsController<StorageProduct, OrderDetailsProduct> {
         let productIDs = order.items.map { $0.productID }
         let predicate = NSPredicate(format: "siteID == %lld AND productID IN %@", siteID, productIDs)
         let descriptor = NSSortDescriptor(key: "name", ascending: true)
 
-        return ResultsController<StorageProduct>(
+        return GenericResultsController<StorageProduct, OrderDetailsProduct>(
             storageManager: storageManager,
             matching: predicate,
-            sortedBy: [descriptor]
+            sortedBy: [descriptor],
+            transformer: { OrderDetailsProduct(storageProduct: $0) }
         )
     }
 }

WooCommerce/Classes/ViewModels/Order Details/Refund Details/RefundDetailsResultController.swift

@@ -7,22 +7,23 @@ import Yosemite
 final class RefundDetailsResultController {
     /// Product ResultsController.
     ///
-    private lazy var productResultsController: ResultsController<StorageProduct> = {
+    private lazy var productResultsController: GenericResultsController<StorageProduct, OrderDetailsProduct> = {
         let storageManager = ServiceLocator.storageManager
         let predicate = NSPredicate(format: "siteID == %lld", siteID)
         let descriptor = NSSortDescriptor(key: "name", ascending: true)
 
-        return ResultsController<StorageProduct>(
+        return GenericResultsController<StorageProduct, OrderDetailsProduct>(
             storageManager: storageManager,
             matching: predicate,
-            sortedBy: [descriptor]
+            sortedBy: [descriptor],
+            transformer: { OrderDetailsProduct(storageProduct: $0) }
         )
     }()
 
     /// Products from an Order
     ///
     var products: [OrderDetailsProduct] {
-        productResultsController.transformedObjects(using: { OrderDetailsProduct(storageProduct: $0) })
+        productResultsController.fetchedObjects
     }
 
     private let siteID: Int64