How to parse dynamic JSON with Flutter?

Issue

I do not understand how to parse a JSON file I get from firebase.

This is the format of the JSON file

{
  "water" : {
    "-MnRJkFC3--ZOTmpF1xN" : {
      "milliliters" : 0.14,
      "time" : "16:26:25"
    },
    "-MnRJkZRwZYEInHfSKIY" : {
      "milliliters" : 48.83,
      "time" : "16:26:25"
    },
    "-MnRJksES18hY765rxxq" : {
      "milliliters" : 41.44,
      "time" : "16:26:25"
    },
    "-MnRJlDn6o4RmiGRJS-E" : {
      "milliliters" : 11.37,
      "time" : "16:26:25"
    }
  }
}

This is how I am reading the JSON file

Future loadSalesData() async {
  final String jsonString = await getJsonFromFirebase();
  final dynamic jsonResponse = json.decode(jsonString);
  for (Map<String, dynamic> i in jsonResponse)
    chartData.add(SalesData.fromJson(i));
  }

The getJsonFromFirebase() looks like this:

Future<String> getJsonFromFirebase() async {
  String url =
      "https://emailpassword. . .seio.com/water.json";
  http.Response response = await http.get(Uri.parse(url));
  return response.body;
}

When you click on the link it send you to the JSON file which looks like this

{
    "-Mnbk2ye2P8bfpaQvNaU": {
        "milliliters": 0.0,
        "time": "18:07:00"
    },
    "-Mnbk6wd-wJze8P0JknK": {
        "milliliters": 0.12,
        "time": "18:07:00"
    },
    "-Mnbk7Ek629vgBu-MiLg": {
        "milliliters": 44.91,
        "time": "18:07:00"
    },
    "-Mnbk7bPuzqwsz9d5nm6": {
        "milliliters": 5.43,
        "time": "18:07:00"
    },
    "-Mnbk7v7MADi7YzEbeFI": {
        "milliliters": 24.54,
        "time": "18:07:00"
    },
    "-Mnbk8DGfqswckdsA1qP": {
        "milliliters": 47.58,
        "time": "18:07:00"
    },
    "-Mnbk8Xw2kJPxLrqCl6h": {
        "milliliters": 13.98,
        "time": "18:07:00"
    }
}

I get the Error

_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'Iterable'

Solution

It seems flutter does not understand that jsonResponse is an iterable because you defined it as dynamic.

Adjust the definition to tell flutter it is a map:

final Map<String, dynamic> jsonResponse = json.decode(jsonString);

Answered By - Canada2000