Use ParseLiveQuery Subscription as a SwiftUI view model (#65)

* Enable LiveQuery Subscription as a SwiftUI VM * Add changes to changelog * update changelog * Don't use Subscription on Linux * fix jazzy script * Update Sources/ParseSwift/LiveQuery/ParseLiveQuery.swift Co-authored-by: Tom Fox <[email protected]> Co-authored-by: Tom Fox <[email protected]>
parse-community · Jan 25, 2021 · 39f20d2 · 39f20d2
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,10 +1,15 @@
 # Parse-Swift Changelog
 
 ### main
-[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/1.0.2...main)
+[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/1.1.0...main)
 * _Contributing to this repo? Add info about your change here to be included in next release_
 
+### 1.1.0
+[Full Changelog](https://github.com/parse-community/Parse-Swift/compare/1.0.2...1.1.0)
+
 __New features__
+- Enable `ParseFile` for Linux ([#64](https://github.com/parse-community/Parse-Swift/pull/64)), thanks to [jt9897253](https://github.com/jt9897253).
+- Use a `ParseLiveQuery` subscription as a SwiftUI view model ([#65](https://github.com/parse-community/Parse-Swift/pull/65)), thanks to [Corey Baker](https://github.com/cbaker6).
 - Idempotency support ([#62](https://github.com/parse-community/Parse-Swift/pull/62)), thanks to [Corey Baker](https://github.com/cbaker6).
 
 ### 1.0.2

diff --git a/ParseSwift.playground/Pages/11 - LiveQuery.xcplaygroundpage/Contents.swift b/ParseSwift.playground/Pages/11 - LiveQuery.xcplaygroundpage/Contents.swift
@@ -32,8 +32,10 @@ struct GameScore: ParseObject {
 //: Create a query just as you normally would.
 var query = GameScore.query("score" > 9)
 
-//: This is how you subscribe your created query
-let subscription = query.subscribe!
+//: This is how you subscribe to your created query using callbacks.
+//: Note that if you want to use subscriptions with SwiftUI, you should
+//: use `let subscription = query.subscribe` instead.
+let subscription = query.subscribeCallback!
 
 //: This is how you receive notifications about the success
 //: of your subscription.
@@ -86,7 +88,7 @@ var query2 = GameScore.query("score" > 50)
 query2.fields("score")
 
 //: Subscribe to your new query.
-let subscription2 = query2.subscribe!
+let subscription2 = query2.subscribeCallback!
 
 //: As before, setup your subscription and event handlers.
 subscription2.handleSubscribe { subscribedQuery, isNew in

diff --git a/ParseSwift.playground/contents.xcplayground b/ParseSwift.playground/contents.xcplayground
@@ -17,4 +17,4 @@
         <page name='13 - Operations'/>		
         <page name='14 - Config'/>
     </pages>
-</playground>
+</playground>
diff --git a/ParseSwift.podspec b/ParseSwift.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = "ParseSwift"
-  s.version  = "1.0.2"
+  s.version  = "1.1.0"
   s.summary  = "Parse Pure Swift SDK"
   s.homepage = "https://github.com/parse-community/Parse-Swift"
   s.authors = {

diff --git a/ParseSwift.xcodeproj/project.pbxproj b/ParseSwift.xcodeproj/project.pbxproj
@@ -2045,7 +2045,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = com.parse.ParseSwift;
 				PRODUCT_NAME = ParseSwift;
 				SKIP_INSTALL = YES;
@@ -2067,7 +2067,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = com.parse.ParseSwift;
 				PRODUCT_NAME = ParseSwift;
 				SKIP_INSTALL = YES;
@@ -2131,7 +2131,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 10.13;
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = com.parse.ParseSwift;
 				PRODUCT_NAME = ParseSwift;
 				SDKROOT = macosx;
@@ -2155,7 +2155,7 @@
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
 				MACOSX_DEPLOYMENT_TARGET = 10.13;
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = com.parse.ParseSwift;
 				PRODUCT_NAME = ParseSwift;
 				SDKROOT = macosx;
@@ -2300,7 +2300,7 @@
 				INFOPLIST_FILE = "ParseSwift-watchOS/Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.parse.ParseSwift-watchOS";
@@ -2328,7 +2328,7 @@
 				INFOPLIST_FILE = "ParseSwift-watchOS/Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.parse.ParseSwift-watchOS";
 				PRODUCT_NAME = ParseSwift;
@@ -2354,7 +2354,7 @@
 				INFOPLIST_FILE = "ParseSwift-tvOS/Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				MTL_ENABLE_DEBUG_INFO = INCLUDE_SOURCE;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.parse.ParseSwift-tvOS";
@@ -2381,7 +2381,7 @@
 				INFOPLIST_FILE = "ParseSwift-tvOS/Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
-				MARKETING_VERSION = 1.0.2;
+				MARKETING_VERSION = 1.1.0;
 				MTL_FAST_MATH = YES;
 				PRODUCT_BUNDLE_IDENTIFIER = "com.parse.ParseSwift-tvOS";
 				PRODUCT_NAME = ParseSwift;

diff --git a/Scripts/jazzy.sh b/Scripts/jazzy.sh
@@ -5,7 +5,7 @@ bundle exec jazzy \
   --author_url http://parseplatform.org \
   --github_url https://github.com/parse-community/Parse-Swift \
   --root-url http://parseplatform.org/Parse-Swift/api/ \
-  --module-version 1.0.2 \
+  --module-version 1.1.0 \
   --theme fullwidth \
   --skip-undocumented \
   --output ./docs/api \

diff --git a/Sources/ParseSwift/LiveQuery/ParseLiveQuery.swift b/Sources/ParseSwift/LiveQuery/ParseLiveQuery.swift
@@ -619,6 +619,10 @@ extension ParseLiveQuery {
         try subscribe(Subscription(query: query))
     }
 
+    func subscribe<T>(_ query: Query<T>) throws -> SubscriptionCallback<T> {
+        try subscribe(SubscriptionCallback(query: query))
+    }
+
     func subscribe<T>(_ handler: T) throws -> T where T: ParseSubscription {
 
         let requestId = requestIdGenerator()
@@ -689,27 +693,33 @@ extension ParseLiveQuery {
 // MARK: ParseLiveQuery - Subscribe
 @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
 public extension Query {
+    #if !os(Linux)
     /**
      Registers the query for live updates, using the default subscription handler,
-     and the default `ParseLiveQuery` client.
+     and the default `ParseLiveQuery` client. Suitable for `ObjectObserved`
+     as the subscription can be used as a SwiftUI publisher. Meaning it can serve
+     indepedently as a ViewModel in MVVM.
      */
     var subscribe: Subscription<ResultType>? {
         try? ParseLiveQuery.client?.subscribe(self)
     }
 
     /**
      Registers the query for live updates, using the default subscription handler,
-     and a specific `ParseLiveQuery` client.
+     and a specific `ParseLiveQuery` client. Suitable for `ObjectObserved`
+     as the subscription can be used as a SwiftUI publisher. Meaning it can serve
+     indepedently as a ViewModel in MVVM.
      - parameter client: A specific client.
      - returns: The subscription that has just been registered
      */
     func subscribe(_ client: ParseLiveQuery) throws -> Subscription<ResultType> {
         try client.subscribe(Subscription(query: self))
     }
+    #endif
 
     /**
      Registers a query for live updates, using a custom subscription handler.
-     - parameter handler: A custom subscription handler.
+     - parameter handler: A custom subscription handler. 
      - returns: Your subscription handler, for easy chaining.
     */
     static func subscribe<T: ParseSubscription>(_ handler: T) throws -> T {
@@ -729,6 +739,24 @@ public extension Query {
     static func subscribe<T: ParseSubscription>(_ handler: T, client: ParseLiveQuery) throws -> T {
         try client.subscribe(handler)
     }
+
+    /**
+     Registers the query for live updates, using the default subscription handler,
+     and the default `ParseLiveQuery` client.
+     */
+    var subscribeCallback: SubscriptionCallback<ResultType>? {
+        try? ParseLiveQuery.client?.subscribe(self)
+    }
+
+    /**
+     Registers the query for live updates, using the default subscription handler,
+     and a specific `ParseLiveQuery` client.
+     - parameter client: A specific client.
+     - returns: The subscription that has just been registered.
+     */
+    func subscribeCallback(_ client: ParseLiveQuery) throws -> SubscriptionCallback<ResultType> {
+        try client.subscribe(SubscriptionCallback(query: self))
+    }
 }
 
 // MARK: ParseLiveQuery - Unsubscribe

diff --git a/Sources/ParseSwift/LiveQuery/Subscription.swift b/Sources/ParseSwift/LiveQuery/Subscription.swift
@@ -56,10 +56,85 @@ private func == <T>(lhs: Event<T>, rhs: Event<T>) -> Bool {
     }
 }
 
+#if !os(Linux)
 /**
- A default implementation of the `ParseSubscription` protocol, using closures for callbacks.
+ A default implementation of the `ParseSubscription` protocol. Suitable for `ObjectObserved`
+ as the subscription can be used as a SwiftUI publisher. Meaning it can serve
+ indepedently as a ViewModel in MVVM.
  */
-open class Subscription<T: ParseObject>: ParseSubscription {
+@available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
+open class Subscription<T: ParseObject>: ParseSubscription, ObservableObject {
+    //The query subscribed to.
+    public var query: Query<T>
+    //The ParseObject
+    public typealias Object = T
+
+    /// Notifies there's a new event related to a specific query.
+    private (set) var event: (query: Query<T>, event: Event<T>)? {
+        willSet {
+            if newValue != nil {
+                subscribed = nil
+                unsubscribed = nil
+                objectWillChange.send()
+            }
+        }
+    }
+
+    /// Notifies when a subscription request has been fulfilled and if it is new.
+    private (set) var subscribed: (query: Query<T>, isNew: Bool)? {
+        willSet {
+            if newValue != nil {
+                unsubscribed = nil
+                event = nil
+                objectWillChange.send()
+            }
+        }
+    }
+
+    /// Notifies when an unsubscribe request has been fulfilled.
+    private (set) var unsubscribed: Query<T>? {
+        willSet {
+            if newValue != nil {
+                subscribed = nil
+                event = nil
+                objectWillChange.send()
+            }
+        }
+    }
+
+    /**
+     Creates a new subscription that can be used to handle updates.
+     */
+    public init(query: Query<T>) {
+        self.query = query
+        self.subscribed = nil
+        self.event = nil
+        self.unsubscribed = nil
+    }
+
+    open func didReceive(_ eventData: Data) throws {
+        // Need to decode the event with respect to the `ParseObject`.
+        let eventMessage = try ParseCoding.jsonDecoder().decode(EventResponse<T>.self, from: eventData)
+        guard let event = Event(event: eventMessage) else {
+            throw ParseError(code: .unknownError, message: "ParseLiveQuery Error: couldn't create event.")
+        }
+        self.event = (query, event)
+    }
+
+    open func didSubscribe(_ new: Bool) {
+        self.subscribed = (query, new)
+    }
+
+    open func didUnsubscribe() {
+        self.unsubscribed = query
+    }
+}
+#endif
+
+/**
+ A default implementation of the `ParseSubscription` protocol using closures for callbacks.
+ */
+open class SubscriptionCallback<T: ParseObject>: ParseSubscription {
     //The query subscribed to.
     public var query: Query<T>
     //The ParseObject
@@ -80,7 +155,8 @@ open class Subscription<T: ParseObject>: ParseSubscription {
      - parameter handler: The callback to register.
      - returns: The same subscription, for easy chaining.
      */
-    @discardableResult open func handleEvent(_ handler: @escaping (Query<T>, Event<T>) -> Void) -> Subscription {
+    @discardableResult open func handleEvent(_ handler: @escaping (Query<T>,
+                                                                   Event<T>) -> Void) -> SubscriptionCallback {
         eventHandlers.append(handler)
         return self
     }
@@ -90,7 +166,8 @@ open class Subscription<T: ParseObject>: ParseSubscription {
      - parameter handler: The callback to register.
      - returns: The same subscription, for easy chaining.
      */
-    @discardableResult open func handleSubscribe(_ handler: @escaping (Query<T>, Bool) -> Void) -> Subscription {
+    @discardableResult open func handleSubscribe(_ handler: @escaping (Query<T>,
+                                                                       Bool) -> Void) -> SubscriptionCallback {
         subscribeHandlers.append(handler)
         return self
     }
@@ -100,7 +177,7 @@ open class Subscription<T: ParseObject>: ParseSubscription {
      - parameter handler: The callback to register.
      - returns: The same subscription, for easy chaining.
      */
-    @discardableResult open func handleUnsubscribe(_ handler: @escaping (Query<T>) -> Void) -> Subscription {
+    @discardableResult open func handleUnsubscribe(_ handler: @escaping (Query<T>) -> Void) -> SubscriptionCallback {
         unsubscribeHandlers.append(handler)
         return self
     }
@@ -123,7 +200,7 @@ open class Subscription<T: ParseObject>: ParseSubscription {
     }
 }
 
-extension Subscription {
+extension SubscriptionCallback {
 
     /**
      Register a callback for when an event occurs of a specific type
@@ -136,7 +213,7 @@ extension Subscription {
      - returns: The same subscription, for easy chaining.
      */
     @discardableResult public func handle(_ eventType: @escaping (T) -> Event<T>,
-                                          _ handler: @escaping (Query<T>, T) -> Void) -> Subscription {
+                                          _ handler: @escaping (Query<T>, T) -> Void) -> SubscriptionCallback {
         return handleEvent { query, event in
             switch event {
             case .entered(let obj) where eventType(obj) == event: handler(query, obj)