Added generics to Query/LiveQuery (#336)

Author: fischerscode

lib/src/network/parse_live_query.dart

@@ -13,9 +13,12 @@ enum LiveQueryEvent { create, enter, update, leave, delete, error }
 
 const String _printConstLiveQuery = 'LiveQuery: ';
 
-class Subscription {
-  Subscription(this.query, this.requestId);
-  QueryBuilder query;
+class Subscription<T extends ParseObject> {
+  Subscription(this.query, this.requestId, {T copyObject}) {
+    _copyObject = copyObject;
+  }
+  QueryBuilder<T> query;
+  T _copyObject;
   int requestId;
   bool _enabled = false;
   final List<String> _liveQueryEvent = <String>[
@@ -30,6 +33,10 @@ class Subscription {
   void on(LiveQueryEvent op, Function callback) {
     eventCallbacks[_liveQueryEvent[op.index]] = callback;
   }
+
+  T get copyObject {
+    return _copyObject;
+  }
 }
 
 enum LiveQueryClientEvent { CONNECTED, DISCONNECTED, USER_DISCONNECTED }
@@ -52,7 +59,6 @@ class LiveQueryReconnectingController with WidgetsBindingObserver {
 
   LiveQueryReconnectingController(
       this._reconnect, this._eventStream, this.debug) {
-
     Connectivity().checkConnectivity().then(_connectivityChanged);
     Connectivity().onConnectivityChanged.listen(_connectivityChanged);
 
@@ -81,7 +87,7 @@ class LiveQueryReconnectingController with WidgetsBindingObserver {
     WidgetsBinding.instance.addObserver(this);
   }
 
-  void _connectivityChanged(ConnectivityResult state){
+  void _connectivityChanged(ConnectivityResult state) {
     if (!_isOnline && state != ConnectivityResult.none) _retryState = 0;
     _isOnline = state != ConnectivityResult.none;
     if (debug) print('$DEBUG_TAG: $state');
@@ -107,9 +113,9 @@ class LiveQueryReconnectingController with WidgetsBindingObserver {
         retryInterval[_retryState] >= 0) {
       _currentTimer =
           Timer(Duration(milliseconds: retryInterval[_retryState]), () {
-            _currentTimer = null;
-            _reconnect();
-          });
+        _currentTimer = null;
+        _reconnect();
+      });
       if (debug)
         print('$DEBUG_TAG: Retrytimer set to ${retryInterval[_retryState]}ms');
       if (_retryState < retryInterval.length - 1) _retryState++;
@@ -128,7 +134,7 @@ class Client {
     _client = client ??
         ParseHTTPClient(
             sendSessionId:
-            autoSendSessionId ?? ParseCoreData().autoSendSessionId,
+                autoSendSessionId ?? ParseCoreData().autoSendSessionId,
             securityContext: ParseCoreData().securityContext);
 
     _debug = isDebugEnabled(objectLevelDebug: debug);
@@ -142,7 +148,7 @@ class Client {
     }
 
     reconnectingController = LiveQueryReconnectingController(
-            () => reconnect(userInitialized: false), getClientEventStream, _debug);
+        () => reconnect(userInitialized: false), getClientEventStream, _debug);
   }
   static Client get instance => _getInstance();
   static Client _instance;
@@ -206,21 +212,24 @@ class Client {
           .add(LiveQueryClientEvent.USER_DISCONNECTED);
   }
 
-  Future<Subscription> subscribe(QueryBuilder query) async {
+  Future<Subscription<T>> subscribe<T extends ParseObject>(
+      QueryBuilder<T> query,
+      {T copyObject}) async {
     if (_webSocket == null) {
       await _clientEventStream.any((LiveQueryClientEvent event) =>
-      event == LiveQueryClientEvent.CONNECTED);
+          event == LiveQueryClientEvent.CONNECTED);
     }
     final int requestId = _requestIdGenerator();
-    final Subscription subscription = Subscription(query, requestId);
+    final Subscription<T> subscription =
+        Subscription<T>(query, requestId, copyObject: copyObject);
     _requestSubScription[requestId] = subscription;
     //After a client connects to the LiveQuery server,
     //it can send a subscribe message to subscribe a ParseQuery.
     _subscribeLiveQuery(subscription);
     return subscription;
   }
 
-  void unSubscribe(Subscription subscription) {
+  void unSubscribe<T extends ParseObject>(Subscription<T> subscription) {
     //Mount message for Unsubscribe
     final Map<String, dynamic> unsubscribeMessage = <String, dynamic>{
       'op': 'unsubscribe',
@@ -382,10 +391,12 @@ class Client {
         final String className = map['className'];
         if (className == '_User') {
           subscription.eventCallbacks[actionData['op']](
-              ParseUser(null, null, null).fromJson(map));
+              (subscription.copyObject ?? ParseUser(null, null, null))
+                  .fromJson(map));
         } else {
           subscription.eventCallbacks[actionData['op']](
-              ParseObject(className).fromJson(map));
+              (subscription.copyObject ?? ParseObject(className))
+                  .fromJson(map));
         }
       } else {
         subscription.eventCallbacks[actionData['op']](actionData);
@@ -399,7 +410,7 @@ class LiveQuery {
     _client = client ??
         ParseHTTPClient(
             sendSessionId:
-            autoSendSessionId ?? ParseCoreData().autoSendSessionId,
+                autoSendSessionId ?? ParseCoreData().autoSendSessionId,
             securityContext: ParseCoreData().securityContext);
 
     _debug = isDebugEnabled(objectLevelDebug: debug);

lib/src/network/parse_query.dart

@@ -296,13 +296,14 @@ class QueryBuilder<T extends ParseObject> {
   /// Finishes the query and calls the server
   ///
   /// Make sure to call this after defining your queries
-  Future<ParseResponse> query() async {
-    return object.query(buildQuery());
+  Future<ParseResponse> query<T extends ParseObject>() async {
+    return object.query<T>(buildQuery());
   }
 
-  Future<ParseResponse> distinct(String className) async {
+  Future<ParseResponse> distinct<T extends ParseObject>(
+      String className) async {
     final String queryString = 'distinct=$className';
-    return object.distinct(queryString);
+    return object.distinct<T>(queryString);
   }
 
   ///Counts the number of objects that match this query

lib/src/objects/parse_object.dart

@@ -84,7 +84,9 @@ class ParseObject extends ParseBase implements ParseCloneable {
       final Uri url = getSanitisedUri(_client, '$_path/$objectId');
       final String body = json.encode(toJson(forApiRQ: true));
       _saveChanges();
-      final Map<String, String> headers = {keyHeaderContentType:keyHeaderContentTypeJson};
+      final Map<String, String> headers = {
+        keyHeaderContentType: keyHeaderContentTypeJson
+      };
       final Response result =
           await _client.put(url, body: body, headers: headers);
       return handleResponse<ParseObject>(
@@ -483,8 +485,7 @@ class ParseObject extends ParseBase implements ParseCloneable {
     _savingChanges.remove(key);
 
     if (offlineOnly) {
-      return ParseResponse()
-        ..success = true;
+      return ParseResponse()..success = true;
     }
 
     try {
@@ -499,8 +500,7 @@ class ParseObject extends ParseBase implements ParseCloneable {
           _unsavedChanges[key] = object;
           _savingChanges[key] = object;
         } else {
-          return ParseResponse()
-            ..success = true;
+          return ParseResponse()..success = true;
         }
       }
     } on Exception {
@@ -509,41 +509,41 @@ class ParseObject extends ParseBase implements ParseCloneable {
       _savingChanges[key] = object;
     }
 
-    return ParseResponse()
-      ..success = false;
+    return ParseResponse()..success = false;
   }
 
   /// Can be used to create custom queries
-  Future<ParseResponse> query(String query) async {
+  Future<ParseResponse> query<T extends ParseObject>(String query) async {
     try {
       final Uri url = getSanitisedUri(_client, '$_path', query: query);
       final Response result = await _client.get(url);
-      return handleResponse<ParseObject>(
+      return handleResponse<T>(
           this, result, ParseApiRQ.query, _debug, parseClassName);
     } on Exception catch (e) {
       return handleException(e, ParseApiRQ.query, _debug, parseClassName);
     }
   }
 
-  Future<ParseResponse> distinct(String query) async {
+  Future<ParseResponse> distinct<T extends ParseObject>(String query) async {
     try {
       final Uri url = getSanitisedUri(_client, '$_aggregatepath', query: query);
       final Response result = await _client.get(url);
-      return handleResponse<ParseObject>(
+      return handleResponse<T>(
           this, result, ParseApiRQ.query, _debug, parseClassName);
     } on Exception catch (e) {
       return handleException(e, ParseApiRQ.query, _debug, parseClassName);
     }
   }
 
   /// Deletes the current object locally and online
-  Future<ParseResponse> delete({String id, String path}) async {
+  Future<ParseResponse> delete<T extends ParseObject>(
+      {String id, String path}) async {
     try {
       path ??= _path;
       id ??= objectId;
       final Uri url = getSanitisedUri(_client, '$_path/$id');
       final Response result = await _client.delete(url);
-      return handleResponse<ParseObject>(
+      return handleResponse<T>(
           this, result, ParseApiRQ.delete, _debug, parseClassName);
     } on Exception catch (e) {
       return handleException(e, ParseApiRQ.delete, _debug, parseClassName);

lib/src/utils/parse_live_list.dart

@@ -80,7 +80,7 @@ class ParseLiveList<T extends ParseObject> {
       query.keysToReturn(List<String>());
     }
 
-    return await query.query();
+    return await query.query<T>();
   }
 
   Future<void> _init() async {
@@ -96,8 +96,9 @@ class ParseLiveList<T extends ParseObject> {
 
     LiveQuery()
         .client
-        .subscribe(QueryBuilder<T>.copy(_query))
-        .then((Subscription subscription) {
+        .subscribe<T>(QueryBuilder<T>.copy(_query),
+            copyObject: _query.object.clone(_query.object.toJson()))
+        .then((Subscription<T> subscription) {
       _liveQuerySubscription = subscription;
       subscription.on(LiveQueryEvent.create, _objectAdded);
       subscription.on(LiveQueryEvent.update, _objectUpdated);
@@ -131,7 +132,7 @@ class ParseLiveList<T extends ParseObject> {
                     .isAfter(currentObject.get<DateTime>(keyVarUpdatedAt))) {
                   QueryBuilder<T> queryBuilder = QueryBuilder<T>.copy(_query)
                     ..whereEqualTo(keyVarObjectId, currentObjectId);
-                  queryBuilder.query().then((ParseResponse result) {
+                  queryBuilder.query<T>().then((ParseResponse result) {
                     if (result.success) {
                       _objectUpdated(result.results.first);
                     }
@@ -206,7 +207,7 @@ class ParseLiveList<T extends ParseObject> {
           ..whereEqualTo(
               keyVarObjectId, _list[index].object.get<String>(keyVarObjectId))
           ..setLimit(1);
-        final ParseResponse response = await queryBuilder.query();
+        final ParseResponse response = await queryBuilder.query<T>();
         if (response.success && response.results != null) {
           _list[index].object = response.results.first;
         } else {