IMVVM foundational types

.gitignore

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+# Forked from https://github.com/github/gitignore/blob/master/Swift.gitignore
+
+# MacOS
+*.DS_Store
+
+## User settings
+xcuserdata/
+
+## Obj-C/Swift specific
+*.hmap
+
+## App packaging
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+# Swift Package Manager
+#
+# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
+Packages/
+.build/
+
+# Xcode automatically generates this directory with a .xcworkspacedata file and xcuserdata
+# hence it is not needed unless you have added a package configuration file to your project
+.swiftpm
+
+build/
+
+# Xcode, since the project is generated using SPM.
+*.xcodeproj
+*.xcworkspace

Package.resolved

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+{
+  "pins" : [
+    {
+      "identity" : "swift-collections",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-collections.git",
+      "state" : {
+        "revision" : "48254824bb4248676bf7ce56014ff57b142b77eb",
+        "version" : "1.0.2"
+      }
+    }
+  ],
+  "version" : 2
+}

Package.swift

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+// swift-tools-version: 5.6
+
+import PackageDescription
+
+let package = Package(
+  name: "IMVVM",
+  platforms: [
+    .iOS(.v13),
+  ],
+  products: [
+    .library(
+      name: "IMVVM",
+      targets: ["IMVVM"]
+    ),
+  ],
+  dependencies: [
+    .package(url: "https://github.com/apple/swift-collections.git", from: "1.0.2"),
+  ],
+  targets: [
+    .target(
+      name: "IMVVM",
+      dependencies: [
+        .product(name: "OrderedCollections", package: "swift-collections"),
+      ]
+    ),
+    .testTarget(
+      name: "IMVVMTests",
+      dependencies: [
+        "IMVVM",
+      ]
+    ),
+  ]
+)

README.md

@@ -1 +1,2 @@
-# imvvm
+# iMVVMFoundation
+The foundational library for base MVVM+Interactor and corresponding utility implementations.

Sources/IMVVM/AnyCancellable+Interactor.swift

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+// MIT License
+//
+// Copyright (c) 2022 Yi Wang
+//
+// 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.
+
+import Combine
+
+extension AnyCancellable {
+  /// When the interactor deinits, the subscription is cancelled.
+  ///
+  /// This function provides the utility to manage Combine subscriptions inside a `Interactor` implementation. For
+  /// example:
+  ///
+  ///     class MyInteractor: Interactor {
+  ///       func buttonDidTap() {
+  ///         somePublisher
+  ///           .sink { ... }
+  ///           .cancelOnDeinit(of: self)
+  ///       }
+  ///     }
+  ///
+  /// - Note: Because this function causes the given interactor to stongly retain the subscription, this means the
+  /// subscription itself should not strongly retain the interactor. Otherwise a retain cycle would occur causing
+  /// memory leaks.
+  ///
+  /// This function is thread-safe. Invocations of this function to the same interactor instance can be performed on
+  /// the different threads.
+  ///
+  /// This function can only be invoked after the given interactor has loaded. This is done via the interactor's
+  /// `viewDidAppear` function. Generally speaking, this interactor should be bound to the lifecycle of a `View`.
+  /// See `ViewLifecycleObserver` for more details.
+  ///
+  /// - Parameters:
+  ///   - interactor: The interactor to bind the subscription's lifecycle to.
+  public func cancelOnDeinit<InteractorType: Interactor>(of interactor: InteractorType) {
+    if !interactor.isLoaded {
+      fatalError("\(interactor) has not been loaded")
+    }
+    interactor.deinitCancelBag.store(self)
+  }
+
+  /// When the interactor's view disappears, the subscription is cancelled.
+  ///
+  /// This function provides the utility to manage Combine subscriptions inside a `Interactor` implementation. For
+  /// example:
+  ///
+  ///     class MyInteractor: Interactor {
+  ///       func buttonDidTap() {
+  ///         somePublisher
+  ///           .sink { ... }
+  ///           .cancelOnViewDidDisappear(of: self)
+  ///       }
+  ///     }
+  ///
+  /// - Note: Because this function causes the given interactor to stongly retain the subscription, this means the
+  /// subscription itself should not strongly retain the interactor. Otherwise a retain cycle would occur causing
+  /// memory leaks.
+  ///
+  /// This function is thread-safe. Invocations of this function to the same interactor instance can be performed on
+  /// the different threads.
+  ///
+  /// This function can only be invoked after the given interactor has received notification that its view has
+  /// appeared. This is done via the interactor's `viewDidAppear` function. Generally speaking, this interactor
+  /// should be bound to the lifecycle of a `View`. See `ViewLifecycleObserver` for more details.
+  ///
+  /// - Parameters:
+  ///   - interactor: The interactor to bind the subscription's lifecycle to.
+  public func cancelOnViewDidDisappear<InteractorType: Interactor>(of interactor: InteractorType) {
+    if !interactor.hasViewAppeared {
+      fatalError("\(interactor)'s view has not appeared")
+    }
+    interactor.viewAppearanceCancelBag.store(self)
+  }
+}

Sources/IMVVM/CancellableBuilder.swift

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+// MIT License
+//
+// Copyright (c) 2022 Yi Wang
+//
+// 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.
+
+import Combine
+
+/// A result builder that allows a variadic number of `AnyCancellable` to be collected into an array.
+@resultBuilder
+public enum CancellableBuilder {
+  public static func buildBlock(_ components: [AnyCancellable]...) -> [AnyCancellable] {
+    components.reduce(into: [], +=)
+  }
+
+  public static func buildExpression(_ expression: Void) -> [AnyCancellable] {
+    []
+  }
+
+  public static func buildExpression(_ expression: AnyCancellable) -> [AnyCancellable] {
+    [expression]
+  }
+
+  /// Convert regular cancellables to AnyCancellable to dispose on deinit.
+  public static func buildExpression(_ expression: any Cancellable) -> [AnyCancellable] {
+    [AnyCancellable(expression.cancel)]
+  }
+
+  public static func buildExpression(_ expression: [AnyCancellable]) -> [AnyCancellable] {
+    expression
+  }
+
+  public static func buildEither(first component: [AnyCancellable]) -> [AnyCancellable] {
+    component
+  }
+
+  public static func buildEither(second component: [AnyCancellable]) -> [AnyCancellable] {
+    component
+  }
+
+  public static func buildArray(_ components: [[AnyCancellable]]) -> [AnyCancellable] {
+    components.reduce(into: [], +=)
+  }
+
+  public static func buildOptional(_ component: [AnyCancellable]?) -> [AnyCancellable] {
+    if let component = component {
+      return component
+    } else {
+      return []
+    }
+  }
+}