How to convert JSON response to Dart Map<String, int> object ...?

Question

I'm getting data from my api as a following JSON object to create chart with the data. I want to covert this DIO response to a Map<String, int> object in my flutter app.

My API response:

{
    "November 20": 1,
    "October 20": 3,
    "September 20": 1
}

My try of creating a map object:

  Future<bool> fetchChartData() async {
    var response = await CasesApiService().getChartData();
    Map<String, dynamic> data = jsonDecode(response.data);
  }

But it shows the following error:

E/flutter ( 4733): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'String'
E/flutter ( 4733): #0      CasesProvider.fetchChartData
package:bdopsApp/providers/casesProvider.dart:86
E/flutter ( 4733): <asynchronous suspension>
E/flutter ( 4733): #1      _CasesChartViewState.build.<anonymous closure>
package:bdopsApp/…/casesApp/casesChart.dart:31
E/flutter ( 4733): #2      _InkResponseState._handleTap
package:flutter/…/material/ink_well.dart:985
E/flutter ( 4733): #3      _InkResponseState.build.<anonymous closure>
package:flutter/…/material/ink_well.dart:1101
E/flutter ( 4733): #4      GestureRecognizer.invokeCallback
package:flutter/…/gestures/recognizer.dart:183
E/flutter ( 4733): #5      TapGestureRecognizer.handleTapUp
package:flutter/…/gestures/tap.dart:598
E/flutter ( 4733): #6      BaseTapGestureRecognizer._checkUp
package:flutter/…/gestures/tap.dart:287
E/flutter ( 4733): #7      BaseTapGestureRecognizer.handlePrimaryPointer
package:flutter/…/gestures/tap.dart:222
E/flutter ( 4733): #8      PrimaryPointerGestureRecognizer.handleEvent
package:flutter/…/gestures/recognizer.dart:476
E/flutter ( 4733): #9      PointerRouter._dispatch
package:flutter/…/gestures/pointer_router.dart:77
E/flutter ( 4733): #10     PointerRouter._dispatchEventToRoutes.<anonymous closure>
package:flutter/…/gestures/pointer_router.dart:122
E/flutter ( 4733): #11     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:377:8)
E/flutter ( 4733): #12     PointerRouter._dispatchEventToRoutes
package:flutter/…/gestures/pointer_router.dart:120
E/flutter ( 4733): #13     PointerRouter.route
package:flutter/…/gestures/pointer_router.dart:106
E/flutter ( 4733): #14     GestureBinding.handleEvent
package:flutter/…/gestures/binding.dart:368
E/flutter ( 4733): #15     GestureBinding.dispatchEvent
package:flutter/…/gestures/binding.dart:348
E/flutter ( 4733): #16     RendererBinding.dispatchEvent
package:flutter/…/rendering/binding.dart:268
E/flutter ( 4733): #17     GestureBinding._handlePointerEventImmediately
package:flutter/…/gestures/binding.dart:303
E/flutter ( 4733): #18     GestureBinding.handlePointerEvent
package:flutter/…/gestures/binding.dart:267
E/flutter ( 4733): #19     GestureBinding._flushPointerEventQueue
package:flutter/…/gestures/binding.dart:225
E/flutter ( 4733): #20     GestureBinding._handlePointerDataPacket
package:flutter/…/gestures/binding.dart:208
E/flutter ( 4733): #21     _rootRunUnary (dart:async/zone.dart:1206:13)
E/flutter ( 4733): #22     _CustomZone.runUnary (dart:async/zone.dart:1100:19)
E/flutter ( 4733): #23     _CustomZone.runUnaryGuarded (dart:async/zone.dart:1005:7)
E/flutter ( 4733): #24     _invoke1 (dart:ui/hooks.dart:265:10)
E/flutter ( 4733): #25     _dispatchPointerDataPacket (dart:ui/hooks.dart:174:5)

N.B: I'm doing my final year project. Therefore, the process I'm following might not be what is used in real world project.

Answer 1

If you run the following example in the dartPad you will get the result that you are looking for:

import 'dart:convert';

void main() {
  
  var jsonString= "{\"November 20\": \"1\",\"October 20\": \"2\",\"September 20\": \"3\"}";
  Map<String, dynamic> data = jsonDecode(jsonString);
  
  print(data);
}

I think you need to check the data that you are getting it from the response.data