Save recursively (parse-community#190)

* Fix Commit: 6ed26e1

* Update parse_encoder.dart

Fix parse encoder bug.

* Fix exception when sendSessionId is null.

* 1. Support save objects recursively.
2. Fix encoding for Add and Remove operations.
3. Fix some exceptions.
4. Support batch request and handle response.

Author: yulingtianxia

README.md

@@ -154,9 +154,9 @@ var response = await dietPlan.remove("listKeywords", ["a"]);
 or using with save function
 
 ```dart
-dietPlan.setAdd('listKeywords', ['a','a','d']);
-dietPlan.setAddUnique('listKeywords', ['a','a','d']);
-dietPlan.setRemove('listKeywords', ['a']);
+dietPlan.setAddAll('listKeywords', ['a','a','d']);
+dietPlan.setAddAllUnique('listKeywords', ['a','a','d']);
+dietPlan.setRemoveAll('listKeywords', ['a']);
 var response = dietPlan.save()
 ```
 

example/lib/main.dart

@@ -105,7 +105,7 @@ class _MyAppState extends State<MyApp> {
 
   Future<void> initInstallation() async {
     final ParseInstallation installation =
-    await ParseInstallation.currentInstallation();
+        await ParseInstallation.currentInstallation();
     final ParseResponse response = await installation.create();
     print(response);
   }
@@ -244,13 +244,13 @@ class _MyAppState extends State<MyApp> {
     /// Update current user from server - Best done to verify user is still a valid user
     response = await ParseUser.getCurrentUserFromServer(
         token: user?.get<String>(keyHeaderSessionToken));
-    if (response.success) {
+    if (response?.success ?? false) {
       user = response.result;
     }
 
     /// log user out
-    response = await user.logout();
-    if (response.success) {
+    response = await user?.logout();
+    if (response?.success ?? false) {
       user = response.result;
     }
 

lib/parse_server_sdk.dart

@@ -3,6 +3,7 @@ library flutter_parse_sdk;
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+import 'dart:math';
 import 'dart:typed_data';
 import 'package:sembast/sembast.dart';
 import 'package:sembast/sembast_io.dart';

lib/src/data/core_store_impl.dart

@@ -16,7 +16,7 @@ class CoreStoreImp implements CoreStore {
 
       if (Platform.isIOS || Platform.isAndroid) {
         dbDirectory = (await getApplicationDocumentsDirectory()).path;
-        final String dbPath = path.join('$dbDirectory+/parse', 'parse.db');
+        final String dbPath = path.join('$dbDirectory/parse', 'parse.db');
         final Database db = await factory.openDatabase(dbPath, codec: codec);
         _instance = CoreStoreImp._internal(db);
       }

lib/src/enums/parse_enum_api_rq.dart

@@ -31,5 +31,6 @@ enum ParseApiRQ {
   decrement,
   getConfigs,
   addConfig,
-  liveQuery
+  liveQuery,
+  batch
 }

lib/src/objects/parse_installation.dart

@@ -206,7 +206,7 @@ class ParseInstallation extends ParseObject {
   ///Subscribes the device to a channel of push notifications.
   void subscribeToChannel(String value) {
     final List<dynamic> channel = <String>[value];
-    setAddUnique('channels', channel);
+    setAddAllUnique('channels', channel);
     save();
   }
 

lib/src/objects/parse_object.dart

@@ -68,38 +68,196 @@ class ParseObject extends ParseBase implements ParseCloneable {
       final String body = json.encode(toJson(forApiRQ: true));
       final Response result = await _client.post(url, body: body);
 
-      //Set the objectId on the object after it is created.
-      //This allows you to perform operations on the object after creation
-      if (result.statusCode == 201) {
-        final Map<String, dynamic> map = json.decode(result.body);
-        objectId = map['objectId'].toString();
-      }
-
       return handleResponse<ParseObject>(
           this, result, ParseApiRQ.create, _debug, className);
     } on Exception catch (e) {
       return handleException(e, ParseApiRQ.create, _debug, className);
     }
   }
 
+  Future<ParseResponse> update() async {
+    try {
+      final Uri url = getSanitisedUri(_client, '$_path/$objectId');
+      final String body = json.encode(toJson(forApiRQ: true));
+      final Response result = await _client.put(url, body: body);
+      return handleResponse<ParseObject>(
+          this, result, ParseApiRQ.save, _debug, className);
+    } on Exception catch (e) {
+      return handleException(e, ParseApiRQ.save, _debug, className);
+    }
+  }
+
   /// Saves the current object online
   Future<ParseResponse> save() async {
-    if (getObjectData()[keyVarObjectId] == null) {
-      return create();
+        final ParseResponse response = await _saveChildren(this);
+    if (response.success) {
+      if (objectId == null) {
+        return create();
+      } else {
+        return update();
+      }
     } else {
-      try {
-        final Uri url = getSanitisedUri(_client, '$_path/$objectId');
-        final String body = json.encode(toJson(forApiRQ: true));
-        final Response result = await _client.put(url, body: body);
-        return handleResponse<ParseObject>(
-            this, result, ParseApiRQ.save, _debug, className);
-      } on Exception catch (e) {
-        return handleException(e, ParseApiRQ.save, _debug, className);
+      return response;
+    }
+  }
+
+  Future<ParseResponse> _saveChildren(dynamic object) async {
+    final Set<ParseObject> uniqueObjects = Set<ParseObject>();
+    final Set<ParseFile> uniqueFiles = Set<ParseFile>();
+    if (!_collectionDirtyChildren(object, uniqueObjects, uniqueFiles,
+        Set<ParseObject>(), Set<ParseObject>())) {
+      final ParseResponse response = ParseResponse();
+      return response;
+    }
+    if (object is ParseObject) {
+      uniqueObjects.remove(object);
+    }
+    for (ParseFile file in uniqueFiles) {
+      final ParseResponse response = await file.save();
+      if (!response.success) {
+        return response;
+      }
+    }
+    List<ParseObject> remaining = uniqueObjects.toList();
+    final List<ParseObject> finished = List<ParseObject>();
+    final ParseResponse totalResponse = ParseResponse()
+      ..success = true
+      ..results = List<dynamic>()
+      ..statusCode = 200;
+    while (remaining.isNotEmpty) {
+      /* Partition the objects into two sets: those that can be save immediately,
+      and those that rely on other objects to be created first. */
+      final List<ParseObject> current = List<ParseObject>();
+      final List<ParseObject> nextBatch = List<ParseObject>();
+      for (ParseObject object in remaining) {
+        if (object._canbeSerialized(finished)) {
+          current.add(object);
+        } else {
+          nextBatch.add(object);
+        }
+      }
+      remaining = nextBatch;
+      // TODO(yulingtianxia): lazy User
+      /* Batch requests have currently a limit of 50 packaged requests per single request
+      This splitting will split the overall array into segments of upto 50 requests
+      and execute them concurrently with a wrapper task for all of them. */
+      final List<List<ParseObject>> chunks = [];
+      for (int i = 0; i < current.length; i += 50) {
+        chunks.add(current.sublist(i, min(current.length, i + 50)));
+      }
+
+      for (List<ParseObject> chunk in chunks) {
+        final List<dynamic> requests = chunk.map<dynamic>((ParseObject obj) {
+          return obj.getRequestJson(obj.objectId == null ? 'POST' : 'PUT');
+        }).toList();
+        final ParseResponse response = await batchRequest(requests, chunk);
+        totalResponse.success &= response.success;
+        if (response.success) {
+          totalResponse.results.addAll(response.results);
+          totalResponse.count += response.count;
+        } else {
+          // TODO(yulingtianxia): If there was an error, we want to roll forward the save changes before rethrowing.
+          totalResponse.statusCode = response.statusCode;
+          totalResponse.error = response.error;
+        }
+      }
+      finished.addAll(current);
+    }
+    return totalResponse;
+  }
+
+  dynamic getRequestJson(String method) {
+    final Uri tempUri = Uri.parse(_client.data.serverUrl);
+    final String parsePath = tempUri.path;
+    final dynamic request = <String, dynamic>{
+      'method': method,
+      'path': '$parsePath$_path' + (objectId != null ? '/$objectId' : ''),
+      'body': toJson(forApiRQ: true)
+    };
+    return request;
+  }
+
+  bool _canbeSerialized(List<dynamic> aftersaving, {dynamic value}) {
+    if (value != null) {
+      if (value is ParseObject) {
+        if (value.objectId == null && !aftersaving.contains(value)) {
+          return false;
+        }
+      } else if (value is Map) {
+        for (dynamic child in value.values) {
+          if (!_canbeSerialized(aftersaving, value: child)) {
+            return false;
+          }
+        }
+      } else if (value is List) {
+        for (dynamic child in value) {
+          if (!_canbeSerialized(aftersaving, value: child)) {
+            return false;
+          }
+        }
       }
+    } else if (!_canbeSerialized(aftersaving, value: getObjectData())) {
+      return false;
     }
+    // TODO(yulingtianxia): handle ACL
+    return true;
   }
 
-  /// Get the instance of ParseRelation class associated with the given key. 
+  bool _collectionDirtyChildren(dynamic object, Set<ParseObject> uniqueObjects,
+      Set<ParseFile> uniqueFiles, Set<ParseObject> seen, Set<ParseObject> seenNew) {
+    if (object is List) {
+      for (dynamic child in object) {
+        if (!_collectionDirtyChildren(
+            child, uniqueObjects, uniqueFiles, seen, seenNew)) {
+          return false;
+        }
+      }
+    } else if (object is Map) {
+      for (dynamic child in object.values) {
+        if (!_collectionDirtyChildren(
+            child, uniqueObjects, uniqueFiles, seen, seenNew)) {
+          return false;
+        }
+      }
+    } else if (object is ParseACL) {
+      // TODO(yulingtianxia): handle ACL
+    } else if (object is ParseFile) {
+      if (object.url == null) {
+        uniqueFiles.add(object);
+      }
+    } else if (object is ParseObject) {
+      /* Check for cycles of new objects.  Any such cycle means it will be
+      impossible to save this collection of objects, so throw an exception. */
+      if (object.objectId != null) {
+        seenNew = Set<ParseObject>();
+      } else {
+        if (seenNew.contains(object)) {
+          // TODO(yulingtianxia): throw an error?
+          return false;
+        }
+        seenNew.add(object);
+      }
+
+      /* Check for cycles of any object.  If this occurs, then there's no
+      problem, but we shouldn't recurse any deeper, because it would be
+      an infinite recursion. */
+      if (seen.contains(object)) {
+        return true;
+      }
+      seen.add(object);
+
+      if (!_collectionDirtyChildren(
+          object.getObjectData(), uniqueObjects, uniqueFiles, seen, seenNew)) {
+        return false;
+      }
+
+      // TODO(yulingtianxia): Check Dirty
+      uniqueObjects.add(object);
+    }
+    return true;
+  }
+
+  /// Get the instance of ParseRelation class associated with the given key.
   ParseRelation getRelation(String key) {
     return ParseRelation(parent: this, key: key);
   }
@@ -115,8 +273,8 @@ class ParseObject extends ParseBase implements ParseCloneable {
   }
 
   /// Removes an element from an Array
-  void setRemove(String key, dynamic values) {
-    _arrayOperation('Remove', key, values);
+  void setRemove(String key, dynamic value) {
+    _arrayOperation('Remove', key, <dynamic>[value]);
   }
 
   /// Remove multiple elements from an array of an object
@@ -159,8 +317,11 @@ class ParseObject extends ParseBase implements ParseCloneable {
     }
   }
 
+  void setAddUnique(String key, dynamic value) {
+    _arrayOperation('AddUnique', key, <dynamic>[value]);
+  }
   /// Add a multiple elements to an array of an object
-  void setAddUnique(String key, List<dynamic> values) {
+  void setAddAllUnique(String key, List<dynamic> values) {
     _arrayOperation('AddUnique', key, values);
   }
 
@@ -175,8 +336,8 @@ class ParseObject extends ParseBase implements ParseCloneable {
   }
 
   /// Add a single element to an array of an object
-  void setAdd(String key, dynamic values) {
-    _arrayOperation('Add', key, values);
+  void setAdd(String key, dynamic value) {
+    _arrayOperation('Add', key, <dynamic>[value]);
   }
 
   void addRelation(String key, List<dynamic> values) {
@@ -208,6 +369,7 @@ class ParseObject extends ParseBase implements ParseCloneable {
 
   /// Used in array Operations in save() method
   void _arrayOperation(String arrayAction, String key, List<dynamic> values) {
+    // TODO(yulingtianxia): Array operations should be incremental. Merge add and remove operation.
     set<Map<String, dynamic>>(
         key, <String, dynamic>{'__op': arrayAction, 'objects': values});
   }

lib/src/objects/parse_relation.dart

@@ -19,19 +19,15 @@ class ParseRelation<T extends ParseObject> {
     if (object != null) {
       _targetClass = object.getClassName();
       _objects.add(object);
-      _parent.addRelation(_key, _objects.map((T value) {
-        return value.toPointer();
-      }).toList());
+      _parent.addRelation(_key, _objects.toList());
     }
   }
 
   void remove(T object) {
     if (object != null) {
       _targetClass = object.getClassName();
       _objects.remove(object);
-      _parent.removeRelation(_key, _objects.map((T value) {
-        return value.toPointer();
-      }).toList());
+      _parent.removeRelation(_key, _objects.toList());
     }
   }