swiftUI support done for now

Sources/LiveQuery.swift

@@ -0,0 +1,165 @@
+//
+//  LiveQuery.swift
+//  CoreStore
+//
+//  Copyright © 2018 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+#if canImport(SwiftUI) && canImport(Combine)
+
+import CoreData
+import Combine
+import SwiftUI
+
+
+#warning("TODO: autoupdating doesn't work yet")
+@available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 15.0, *)
+@propertyWrapper
+public struct LiveQuery<Result: LiveResult>: DynamicProperty {
+    
+    // MARK: Public
+    
+    @Environment(\.dataStack)
+    public var dataStack: DataStack
+    
+    public typealias ObjectType = Result.ObjectType
+    
+    
+    // MARK: @propertyWrapper
+    
+    public fileprivate(set) var wrappedValue: Result {
+        
+        get {
+
+            return self.nonMutatingWrappedValue.wrappedValue
+        }
+        set {
+            
+            self.nonMutatingWrappedValue = LazyNonmutating { newValue }
+        }
+    }
+    
+    public var projectedValue: Result {
+        
+        return self.wrappedValue
+    }
+    
+
+    // MARK: DynamicProperty
+
+    public mutating func update() {
+
+        SwiftUI.withAnimation {
+
+            let dataStack = self.dataStack
+            if self.set(dataStack: dataStack) {
+                
+                return
+            }
+            self.wrappedValue = self.newWrappedValue(dataStack)
+        }
+    }
+    
+    
+    // MARK: FilePrivate
+    
+    fileprivate let newWrappedValue: (DataStack) -> Result
+    
+    fileprivate init(newWrappedValue: @escaping (DataStack) -> Result) {
+        
+        self.newWrappedValue = newWrappedValue
+    }
+    
+    
+    // MARK: Private
+    
+    private var nonMutatingWrappedValue: LazyNonmutating<Result> = .init { fatalError() }
+    
+    private var currentDataStack: DataStack?
+    
+    private mutating func set(dataStack: DataStack) -> Bool {
+
+        guard self.currentDataStack != dataStack else {
+            
+            return false
+        }
+        self.currentDataStack = dataStack
+        
+        let newWrappedValue = self.newWrappedValue
+        self.nonMutatingWrappedValue = LazyNonmutating<Result> {
+            
+            newWrappedValue(dataStack)
+        }
+        return true
+    }
+    
+    
+    // MARK: - LazyNonmutating
+    
+    fileprivate final class LazyNonmutating<Value> {
+        
+        // MARK: FilePrivate
+        
+        lazy var wrappedValue: Value = self.initializer()
+
+        init(_ initializer: @escaping () -> Value) {
+            
+            self.initializer = initializer
+        }
+        
+
+        // MARK: Private
+        
+        private var initializer: () -> Value
+    }
+}
+
+
+#if canImport(UIKit) || canImport(AppKit)
+
+@available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 15.0, *)
+extension LiveQuery {
+
+    public init<D: DynamicObject>(liveList: LiveList<D>) where Result == LiveList<D> {
+
+        self.init(
+            newWrappedValue: { _ in liveList }
+        )
+    }
+
+    public init<D: DynamicObject>(_ clauseChain: FetchChainBuilder<D>) where Result == LiveList<D> {
+        
+        self.init(
+            newWrappedValue: { $0.liveList(clauseChain) }
+        )
+    }
+
+    public init<D: DynamicObject>(_ clauseChain: SectionMonitorChainBuilder<D>) where Result == LiveList<D> {
+        
+        self.init(
+            newWrappedValue: { $0.liveList(clauseChain) }
+        )
+    }
+}
+
+#endif
+
+#endif