im relatively new to flutter. I'm using an async future and a future building to populate a widget with the returned data which is in a nested object. The problem I'm having is to access the nested list of objects inside my object. I keep getting [Instance of 'License', Instance of 'License', Instance of 'License', Instance of 'License', Instance of 'License'] when i log snapshot.data!.license instead of json?, and when i try to creating a listview the output is empty. My view looks like this:

body: SingleChildScrollView(
            child: new FutureBuilder<Profile>(
                future: _license,
                builder: (context, snapshot) {
                  if (snapshot.hasData == false || snapshot.data == null) {
                    return CircularProgressIndicator();
                  } else if (snapshot.hasError) {
                    return Text("${snapshot.error}");
                  } else {
                    var x = snapshot.data!.license;

                    x.map((e) {
                      print(e);
                      return Row(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Column(
                                crossAxisAlignment: CrossAxisAlignment.start,
                                children: [
                                  Text(e.fromDate.toString()),
                                ])
                          ]);
                    });
                  }
                  return const Center(child: CircularProgressIndicator());
                })

        )

And my object looks like this :

{
"id": "1",
"license": [
        {
            "license_no": "229451",
            "from_date": "2020-11-12",
            "to_date": "2021-11-30",
            "workStation": "Johpas Clinic"
        },
        {
            "license_no": "189024",
            "from_date": "2019-11-04",
            "to_date": "2020-11-30",
            "workStation": null
        },
        {
            "license_no": "109872",
            "from_date": "2016-11-30",
            "to_date": "2019-11-30",
            "workStation": null
        },
        {
            "license_no": "066356",
            "from_date": "2013-11-30",
            "to_date": "2016-11-30",
            "workStation": null
        },
        {
            "license_no": "007853    ",
            "from_date": "2010-11-30",
            "to_date": "2013-11-30",
            "workStation": null
        }
    ]
}

CodePudding user response：

You can create a toJson method in the License class and then use that for logging purposes, or override the toString method that is added to every class created in dart.

class License {
String id;
License(this.id);

Map<String, dynamic> toJson() => {
 'id' : id,
};

CodePudding user response：

I used indexes to access the data

 } else if(snapshot.hasData) {
                Profile? data = snapshot.data;

                return ListView.builder(
                    itemCount: data!.length,
                    shrinkWrap: true,
                    primary: false,
                    itemBuilder: (BuildContext context, int index) {
                      return Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          16.height,
                            Text(("Education History").validate(), style: boldTextStyle()),
                          16.height,
                          // child: Text(data.license[index].fromDate.toString()),
                          Row(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              16.width,
                              Column(
                                crossAxisAlignment: CrossAxisAlignment.start,
                                children: [
                                  Text((data.registration[index].cadre).toString(),
                                      style: boldTextStyle(
                                          size: 14, color: blackColor)),
                                  8.height,
                                  Text(
                                      (data.registration[index].cadreText.toString())
                                          .validate(),
                                      style: boldTextStyle(
                                          size: 13, color: Colors.green)),
                                  8.height,
                                  Text(
                                      (data.registration[index].regNo
                                              .toString())
                                          .validate(),
                                      style: boldTextStyle(
                                          size: 12, color: mlColorRed)),
                                ],
                              ).expand()
                            ],
                          ).paddingBottom(16.0),
                        ],
                      ).paddingAll(16.0);
                    }
                );
                
              }