Parsing a JSON API response

Question

An API is giving me a JSON response like so :

{
    "amountCredited":0,
    "isFirstOrder":false,
     "orderItems":[
       {
          "_id":624342e1c66be9001d501230,
          "status":2,
          "pinCode":749326,
          "kioskId":61bb3982089a66001db4ab77,
          "kioskActivityId":620668ad433322b99557c874
          }
       ]
}

I'm trying to access the data inside the "orderItems" in order to feed it to an existing parsing model in the App

order = OrderItemModel.fromJson(response.body['orderItems'] as Map<String, dynamic>);

but since the data inside orderItems JSON response is inside an array I can't access it this way..

How can I access it knowing that this JSON "orderItems" array will always only have one item as a response ?

---

Would something like response.body['orderItems' : [0]] enable me to access the first item data ?

Answer 1

Since you always know that the array will always have only one item. We'll first make it a List & then access the first element.

order = OrderItemModel.fromJson((response.body['orderItems'] as List<dynamic>).first as Map<String, dynamic>);

To understand it a bit better refer to the code below:

The JSON response contains an array, which we need to access.

final ordersArray = response.body['orderItems'] as List<dynamic>;

Then we want to access the first order (according to the question)

final firstOrder = ordersArray.first as Map<String, dynamic>;

Once we have the order, we'll convert it to the model

final order = OrderItemModel.fromJson(firstOrder);

EDIT: as it was pointed out in a comment List objects have a getter called first which can be used to get the first element, the code has been updated with that.

Answer 2

You need to convert as Map and List because Flutter deal only with this datatypes. For example:

Map order1 = {
          "_id":"624342e1c66be9001d501230",
          "status":2,
          "pinCode":749326,
          "kioskId":"61bb3982089a66001db4ab77",
          "kioskActivityId":"620668ad433322b99557c874"
          };
  Map order2 = {
          "_id":"224342e1c66be9001d501232",
          "status":1,
          "pinCode":248023,
          "kioskId":"41bb3982089a66001db4ab74",
          "kioskActivityId":"720668ad433322b99557c875"
          };
  Map m = {
    "amountCredited":0,
    "isFirstOrder":false,
     "orderItems":[
       order1,
       order2
       ]
};
  
  
  print(m['orderItems'][1]);
  print(m['orderItems'][1]['pinCode']);

The result will be:

 {_id: 224342e1c66be9001d501232, status: 1, pinCode: 248023, kioskId: 41bb3982089a66001db4ab74, kioskActivityId: 720668ad433322b99557c875}
248023