Fix LiveQuery reconnection bug

CHANGELOG.md

@@ -4,6 +4,9 @@
 [Full Changelog](https://github.com/parse-community/Parse-Swift/compare/1.8.3...main)
 * _Contributing to this repo? Add info about your change here to be included in the next release_
 
+__Fixes__
+- Fixed a bug in LiveQuery that prevented reconnecting after a connection was closed. Also added a sendPing method to LiveQuery ([#172](https://github.com/parse-community/Parse-Swift/pull/172)), thanks to [Corey Baker](https://github.com/cbaker6).
+
 ### 1.8.3
 [Full Changelog](https://github.com/parse-community/Parse-Swift/compare/1.8.2...1.8.3)
 

ParseSwift.playground/Pages/11 - LiveQuery.xcplaygroundpage/Contents.swift

@@ -10,7 +10,12 @@
 import PlaygroundSupport
 import Foundation
 import ParseSwift
+#if canImport(SwiftUI)
 import SwiftUI
+#if canImport(Combine)
+import Combine
+#endif
+#endif
 PlaygroundPage.current.needsIndefiniteExecution = true
 
 initializeParse()
@@ -38,8 +43,9 @@ struct GameScore: ParseObject {
 //: Be sure you have LiveQuery enabled on your server.
 
 //: Create a query just as you normally would.
-var query = GameScore.query("score" > 9)
+var query = GameScore.query("score" < 11)
 
+#if canImport(SwiftUI)
 //: To use subscriptions inside of SwiftUI
 struct ContentView: View {
 
@@ -55,7 +61,7 @@ struct ContentView: View {
                 Text("Unsubscribed from query!")
             } else if let event = subscription.event {
 
-                //: This is how you register to receive notificaitons of events related to your LiveQuery.
+                //: This is how you register to receive notifications of events related to your LiveQuery.
                 switch event.event {
 
                 case .entered(let object):
@@ -93,6 +99,7 @@ struct ContentView: View {
 }
 
 PlaygroundPage.current.setLiveView(ContentView())
+#endif
 
 //: This is how you subscribe to your created query using callbacks.
 let subscription = query.subscribeCallback!
@@ -109,7 +116,7 @@ subscription.handleSubscribe { subscribedQuery, isNew in
     }
 }
 
-//: This is how you register to receive notificaitons of events related to your LiveQuery.
+//: This is how you register to receive notifications of events related to your LiveQuery.
 subscription.handleEvent { _, event in
     switch event {
 
@@ -126,10 +133,19 @@ subscription.handleEvent { _, event in
     }
 }
 
+//: Ping the LiveQuery server
+ParseLiveQuery.client?.sendPing { error in
+    if let error = error {
+        print("Error pinging LiveQuery server: \(error)")
+    } else {
+        print("Successfully pinged server!")
+    }
+}
+
 //: Now go to your dashboard, go to the GameScore table and add, update or remove rows.
 //: You should receive notifications for each.
 
-//: This is how you register to receive notificaitons about being unsubscribed.
+//: This is how you register to receive notifications about being unsubscribed.
 subscription.handleUnsubscribe { query in
     print("Unsubscribed from \(query)")
 }
@@ -141,6 +157,16 @@ do {
     print(error)
 }
 
+//: Ping the LiveQuery server. This should produce an error
+//: because LiveQuery is disconnected.
+ParseLiveQuery.client?.sendPing { error in
+    if let error = error {
+        print("Error pinging LiveQuery server: \(error)")
+    } else {
+        print("Successfully pinged server!")
+    }
+}
+
 //: Create a new query.
 var query2 = GameScore.query("score" > 50)
 
@@ -177,11 +203,86 @@ subscription2.handleEvent { _, event in
     }
 }
 
-//: Now go to your dashboard, go to the GameScore table and add, update or remove rows.
-//: You should receive notifications for each, but only with your fields information.
+//: To close the current LiveQuery connection.
+ParseLiveQuery.client?.close()
+
+//: To close all LiveQuery connections use:
+//ParseLiveQuery.client?.closeAll()
+
+//: Ping the LiveQuery server. This should produce an error
+//: because LiveQuery is disconnected.
+ParseLiveQuery.client?.sendPing { error in
+    if let error = error {
+        print("Error pinging LiveQuery server: \(error)")
+    } else {
+        print("Successfully pinged server!")
+    }
+}
+
+//: Subscribe to your new query.
+let subscription3 = query2.subscribeCallback!
+
+//: As before, setup your subscription and event handlers.
+subscription3.handleSubscribe { subscribedQuery, isNew in
+
+    //: You can check this subscription is for this query.
+    if isNew {
+        print("Successfully subscribed to new query \(subscribedQuery)")
+    } else {
+        print("Successfully updated subscription to new query \(subscribedQuery)")
+    }
+}
+
+subscription3.handleEvent { _, event in
+    switch event {
+
+    case .entered(let object):
+        print("Entered: \(object)")
+    case .left(let object):
+        print("Left: \(object)")
+    case .created(let object):
+        print("Created: \(object)")
+    case .updated(let object):
+        print("Updated: \(object)")
+    case .deleted(let object):
+        print("Deleted: \(object)")
+    }
+}
+
+//: Now lets subscribe to an additional query.
+let subscription4 = query.subscribeCallback!
+
+//: This is how you receive notifications about the success
+//: of your subscription.
+subscription4.handleSubscribe { subscribedQuery, isNew in
+
+    //: You can check this subscription is for this query
+    if isNew {
+        print("Successfully subscribed to new query \(subscribedQuery)")
+    } else {
+        print("Successfully updated subscription to new query \(subscribedQuery)")
+    }
+}
+
+//: This is how you register to receive notifications of events related to your LiveQuery.
+subscription4.handleEvent { _, event in
+    switch event {
+
+    case .entered(let object):
+        print("Entered: \(object)")
+    case .left(let object):
+        print("Left: \(object)")
+    case .created(let object):
+        print("Created: \(object)")
+    case .updated(let object):
+        print("Updated: \(object)")
+    case .deleted(let object):
+        print("Deleted: \(object)")
+    }
+}
 
-//: This is how you register to receive notificaitons about being unsubscribed.
-subscription2.handleUnsubscribe { query in
+//: Now we will will unsubscribe from one of the subsriptions, but maintain the connection.
+subscription3.handleUnsubscribe { query in
     print("Unsubscribed from \(query)")
 }
 
@@ -192,5 +293,14 @@ do {
     print(error)
 }
 
+//: Ping the LiveQuery server
+ParseLiveQuery.client?.sendPing { error in
+    if let error = error {
+        print("Error pinging LiveQuery server: \(error)")
+    } else {
+        print("Successfully pinged server!")
+    }
+}
+
 PlaygroundPage.current.finishExecution()
 //: [Next](@next)

ParseSwift.xcodeproj/project.pbxproj

@@ -384,6 +384,13 @@
 		91678706259BC5D400BB5B4E /* ParseCloudTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 916786EF259BC59600BB5B4E /* ParseCloudTests.swift */; };
 		91678710259BC5D600BB5B4E /* ParseCloudTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 916786EF259BC59600BB5B4E /* ParseCloudTests.swift */; };
 		9167871A259BC5D600BB5B4E /* ParseCloudTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 916786EF259BC59600BB5B4E /* ParseCloudTests.swift */; };
+		918CED592684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */; };
+		918CED5A2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */; };
+		918CED5B2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */; };
+		918CED5C2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */; };
+		918CED5E268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED5D268618C600CFDC83 /* ParseLiveQueryCombineTests.swift */; };
+		918CED5F268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED5D268618C600CFDC83 /* ParseLiveQueryCombineTests.swift */; };
+		918CED60268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 918CED5D268618C600CFDC83 /* ParseLiveQueryCombineTests.swift */; };
 		9194657824F16E330070296B /* ParseACLTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9194657724F16E330070296B /* ParseACLTests.swift */; };
 		91B40651267A66ED00B129CD /* ParseErrorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 91B40650267A66ED00B129CD /* ParseErrorTests.swift */; };
 		91B40652267A66ED00B129CD /* ParseErrorTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 91B40650267A66ED00B129CD /* ParseErrorTests.swift */; };
@@ -707,6 +714,8 @@
 		9158916A256A07DD0024BE9A /* README.md */ = {isa = PBXFileReference; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 		916786E1259B7DDA00BB5B4E /* ParseCloud.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseCloud.swift; sourceTree = "<group>"; };
 		916786EF259BC59600BB5B4E /* ParseCloudTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseCloudTests.swift; sourceTree = "<group>"; };
+		918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "ParseLiveQuery+combine.swift"; sourceTree = "<group>"; };
+		918CED5D268618C600CFDC83 /* ParseLiveQueryCombineTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseLiveQueryCombineTests.swift; sourceTree = "<group>"; };
 		9194657724F16E330070296B /* ParseACLTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseACLTests.swift; sourceTree = "<group>"; };
 		91B40650267A66ED00B129CD /* ParseErrorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseErrorTests.swift; sourceTree = "<group>"; };
 		91CB9536265966DF0043E5D6 /* ParseAnanlyticsCombineTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ParseAnanlyticsCombineTests.swift; sourceTree = "<group>"; };
@@ -888,6 +897,7 @@
 				70110D5B2506ED0E0091CC1D /* ParseInstallationTests.swift */,
 				70386A5B25D9A4010048EC1B /* ParseLDAPCombineTests.swift */,
 				70386A4525D99C8B0048EC1B /* ParseLDAPTests.swift */,
+				918CED5D268618C600CFDC83 /* ParseLiveQueryCombineTests.swift */,
 				7003963A25A288100052CB31 /* ParseLiveQueryTests.swift */,
 				70C7DC2024D20F190050419B /* ParseObjectBatchTests.swift */,
 				7044C1DE25C5C70D0011F6E7 /* ParseObjectCombine.swift */,
@@ -1044,10 +1054,11 @@
 			isa = PBXGroup;
 			children = (
 				70510AAB259EE25E00FEA700 /* LiveQuerySocket.swift */,
-				70C5655825AA147B00BDD57F /* ParseLiveQueryConstants.swift */,
 				7003959425A10DFC0052CB31 /* Messages.swift */,
 				700395A225A119430052CB31 /* Operations.swift */,
 				7003960825A184EF0052CB31 /* ParseLiveQuery.swift */,
+				918CED582684C74000CFDC83 /* ParseLiveQuery+combine.swift */,
+				70C5655825AA147B00BDD57F /* ParseLiveQueryConstants.swift */,
 				700395B925A1470F0052CB31 /* Subscription.swift */,
 				705D950725BE4C08003EF6F8 /* SubscriptionCallback.swift */,
 				700395DE25A147C40052CB31 /* Protocols */,
@@ -1651,6 +1662,7 @@
 				7044C1C825C5B2B10011F6E7 /* ParseAuthentication+combine.swift in Sources */,
 				707A3BF125B0A4F0000D215C /* ParseAuthentication.swift in Sources */,
 				70D1BE7325BB43EB00A42E7C /* BaseConfig.swift in Sources */,
+				918CED592684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */,
 				70386A0625D9718C0048EC1B /* Data+hexString.swift in Sources */,
 				F97B465F24D9C7B500F4A88B /* KeychainStore.swift in Sources */,
 				70170A442656B02D0070C905 /* ParseAnalytics.swift in Sources */,
@@ -1735,6 +1747,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				918CED5E268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */,
 				911DB13624C4FC100027F3C7 /* ParseObjectTests.swift in Sources */,
 				70E09E1C262F0634002DD451 /* ParsePointerCombineTests.swift in Sources */,
 				89899D592603CF3E002E2043 /* ParseTwitterTests.swift in Sources */,
@@ -1805,6 +1818,7 @@
 				7044C1C925C5B2B10011F6E7 /* ParseAuthentication+combine.swift in Sources */,
 				707A3BF225B0A4F0000D215C /* ParseAuthentication.swift in Sources */,
 				70D1BE7425BB43EB00A42E7C /* BaseConfig.swift in Sources */,
+				918CED5A2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */,
 				70386A0725D9718C0048EC1B /* Data+hexString.swift in Sources */,
 				F97B466024D9C7B500F4A88B /* KeychainStore.swift in Sources */,
 				70170A452656B02D0070C905 /* ParseAnalytics.swift in Sources */,
@@ -1898,6 +1912,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				918CED60268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */,
 				709B98512556ECAA00507778 /* ParseEncoderExtraTests.swift in Sources */,
 				70E09E1E262F0634002DD451 /* ParsePointerCombineTests.swift in Sources */,
 				89899D642603CF3F002E2043 /* ParseTwitterTests.swift in Sources */,
@@ -1960,6 +1975,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				918CED5F268618C600CFDC83 /* ParseLiveQueryCombineTests.swift in Sources */,
 				70F2E2B6254F283000B2EA5C /* ParseACLTests.swift in Sources */,
 				70E09E1D262F0634002DD451 /* ParsePointerCombineTests.swift in Sources */,
 				89899D632603CF3E002E2043 /* ParseTwitterTests.swift in Sources */,
@@ -2030,6 +2046,7 @@
 				7044C1CB25C5B2B10011F6E7 /* ParseAuthentication+combine.swift in Sources */,
 				707A3BF425B0A4F0000D215C /* ParseAuthentication.swift in Sources */,
 				70D1BE7625BB43EB00A42E7C /* BaseConfig.swift in Sources */,
+				918CED5C2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */,
 				70386A0925D9718C0048EC1B /* Data+hexString.swift in Sources */,
 				F97B460524D9C6F200F4A88B /* NoBody.swift in Sources */,
 				70170A472656B02D0070C905 /* ParseAnalytics.swift in Sources */,
@@ -2122,6 +2139,7 @@
 				7044C1CA25C5B2B10011F6E7 /* ParseAuthentication+combine.swift in Sources */,
 				707A3BF325B0A4F0000D215C /* ParseAuthentication.swift in Sources */,
 				70D1BE7525BB43EB00A42E7C /* BaseConfig.swift in Sources */,
+				918CED5B2684C74000CFDC83 /* ParseLiveQuery+combine.swift in Sources */,
 				70386A0825D9718C0048EC1B /* Data+hexString.swift in Sources */,
 				F97B460424D9C6F200F4A88B /* NoBody.swift in Sources */,
 				70170A462656B02D0070C905 /* ParseAnalytics.swift in Sources */,

Sources/ParseSwift/LiveQuery/LiveQuerySocket.swift

@@ -53,6 +53,9 @@ extension LiveQuerySocket {
             .encode(StandardMessage(operation: .connect,
                                     additionalProperties: true))
         guard let encodedAsString = String(data: encoded, encoding: .utf8) else {
+            let error = ParseError(code: .unknownError,
+                                   message: "Couldn't encode connect message: \(encoded)")
+            completion(error)
             return
         }
         task.send(.string(encodedAsString)) { error in
@@ -104,6 +107,15 @@ extension LiveQuerySocket {
     }
 }
 
+// MARK: Ping
+@available(macOS 10.15, iOS 13.0, macCatalyst 13.0, watchOS 6.0, tvOS 13.0, *)
+extension LiveQuerySocket {
+
+    func sendPing(_ task: URLSessionWebSocketTask, pongReceiveHandler: @escaping (Error?) -> Void) {
+        task.sendPing(pongReceiveHandler: pongReceiveHandler)
+    }
+}
+
 // MARK: URLSession
 @available(macOS 10.15, iOS 13.0, macCatalyst 13.0, watchOS 6.0, tvOS 13.0, *)
 extension URLSession {

Sources/ParseSwift/LiveQuery/ParseLiveQuery+combine.swift

@@ -0,0 +1,51 @@
+//
+//  ParseLiveQuery+combine.swift
+//  ParseSwift
+//
+//  Created by Corey Baker on 6/24/21.
+//  Copyright © 2021 Parse Community. All rights reserved.
+//
+
+#if canImport(Combine)
+import Foundation
+import Combine
+
+@available(macOS 10.15, iOS 13.0, macCatalyst 13.0, watchOS 6.0, tvOS 13.0, *)
+extension ParseLiveQuery {
+    // MARK: Functions - Combine
+
+    /**
+     Manually establish a connection to the `ParseLiveQuery` Server. Publishes when established.
+      - parameter isUserWantsToConnect: Specifies if the user is calling this function. Defaults to `true`.
+      - returns: A publisher that eventually produces a single value and then finishes or fails.
+    */
+    public func openPublisher(isUserWantsToConnect: Bool = true) -> Future<Void, Error> {
+        Future { promise in
+            self.open(isUserWantsToConnect: isUserWantsToConnect) { error in
+                guard let error = error else {
+                    promise(.success(()))
+                    return
+                }
+                promise(.failure(error))
+            }
+        }
+    }
+
+    /**
+     Sends a ping frame from the client side. Publishes when a pong is received from the
+     server endpoint.
+     - returns: A publisher that eventually produces a single value and then finishes or fails.
+    */
+    public func sendPingPublisher() -> Future<Void, Error> {
+        Future { promise in
+            self.sendPing { error in
+                guard let error = error else {
+                    promise(.success(()))
+                    return
+                }
+                promise(.failure(error))
+            }
+        }
+    }
+}
+#endif