Print deprecation warning from Kuzzle

doc/2/core-classes/kuzzle/constructor/index.md

@@ -26,6 +26,7 @@ Kuzzle(
     queueTTL,
     queueMaxSize = 500,
     replayInterval,
+    deprecationWarnings = true,
     globalVolatile,
   })
 ```

lib/src/kuzzle.dart

@@ -16,6 +16,7 @@ import 'kuzzle/request.dart';
 import 'kuzzle/response.dart';
 import 'protocols/abstract.dart';
 import 'protocols/events.dart';
+import 'utils/deprecation.dart';
 
 enum OfflineMode { manual, auto }
 
@@ -31,11 +32,13 @@ class _KuzzleQueuedRequest {
 }
 
 class Kuzzle extends KuzzleEventEmitter {
+
   Kuzzle(
     this.protocol, {
     this.autoQueue = false,
     this.autoReplay = false,
     this.autoResubscribe = true,
+    bool deprecationWarnings = true,
     this.eventTimeout = 200,
     this.offlineMode = OfflineMode.manual,
     this.offlineQueueLoader,
@@ -44,7 +47,10 @@ class Kuzzle extends KuzzleEventEmitter {
     this.queueMaxSize = 500,
     this.replayInterval,
     this.globalVolatile,
-  }) {
+  }) :
+    deprecationHandler = 
+      DeprecationHandler(deprecationWarning: deprecationWarnings)
+    {
     if (offlineMode == OfflineMode.auto) {
       autoQueue = true;
       autoReplay = true;
@@ -128,6 +134,7 @@ class Kuzzle extends KuzzleEventEmitter {
   final OfflineMode offlineMode;
   final Function offlineQueueLoader;
   final Function queueFilter;
+  final DeprecationHandler deprecationHandler;
 
   /// Automatically queue all requests during offline mode
   bool autoQueue;
@@ -395,7 +402,7 @@ class Kuzzle extends KuzzleEventEmitter {
 
     _requests.add(request.requestId);
     // todo: implement query options
-    return protocol.query(request);
+    return protocol.query(request).then(deprecationHandler.logDeprecation);
   }
 
   KuzzleController operator [](String accessor) => _controllers[accessor];

lib/src/kuzzle/response.dart

@@ -1,10 +1,13 @@
+import 'package:kuzzle/src/utils/deprecation.dart';
+
 import 'errors.dart';
 
 class KuzzleResponse {
   KuzzleResponse({
     this.action,
     this.collection,
     this.controller,
+    this.deprecations,
     this.error,
     this.index,
     this.room,
@@ -17,6 +20,7 @@ class KuzzleResponse {
     action = json['action'] as String;
     collection = json['collection'] as String;
     controller = json['controller'] as String;
+    deprecations = Deprecation.fromJsonList(json);
     error = json['error'] == null ? null : KuzzleError.fromJson(json);
     index = json['index'] as String;
     protocol = json['protocol'] as String;
@@ -43,10 +47,12 @@ class KuzzleResponse {
     if (controller != null) {
       map['controller'] = controller;
     }
+    if (deprecations != null) {
+      map['deprecations'] = Deprecation.toJsonList(deprecations);
+    }
     if (error != null) {
       map['error'] = error.toJson();
     }
-  String users;
     if (index != null) {
       map['index'] = index;
     }
@@ -90,6 +96,7 @@ class KuzzleResponse {
   String action;
   String collection;
   String controller;
+  List<Deprecation> deprecations;
   KuzzleError error;
   String index;
   String protocol;

lib/src/utils/deprecation.dart

@@ -0,0 +1,62 @@
+import 'dart:convert';
+import 'dart:developer';
+import 'package:kuzzle/src/kuzzle/response.dart';
+
+class DeprecationHandler {
+
+  DeprecationHandler({ this.deprecationWarning = true });
+
+  final bool deprecationWarning;
+
+  KuzzleResponse logDeprecation(KuzzleResponse response) {
+    if (deprecationWarning && response.deprecations.isNotEmpty) {
+      for (final deprecation in response.deprecations) {
+        log(
+          '${response.action}: ${deprecation.message}',
+          name: 'Deprecation Warning',
+          level: 900 // Warning
+        );
+      }
+    }
+    return response;
+  }
+}
+
+class Deprecation {
+  Deprecation(this.message, this.version);
+
+  factory Deprecation.fromJson(Map<String, dynamic> json) => 
+    Deprecation(json['message'] as String, json['version'] as String);
+
+  static List<Deprecation> fromJsonList(Map<String, dynamic> json) {
+    if (json['deprecations'] == null || json['deprecations'] is! List<Object>) {
+      return [];
+    }
+    final list = <Deprecation>[];
+    for (final deprecation in json['deprecations']) {
+      list.add(
+        Deprecation.fromJson(
+          deprecation as Map<String, dynamic>
+        )
+      );
+    }
+    return list;
+  }
+
+  final String message;
+  final String version;
+
+  Map<String, dynamic> toJson() => {
+    'message': message,
+    'version': version,
+  };
+
+  static String toJsonList(List<Deprecation> list) {
+    final jsonList = <Map<String, dynamic>>[]; 
+    for (final deprecation in list) {
+      jsonList.add(deprecation.toJson());
+    }
+    return jsonEncode(jsonList);
+  }
+
+}