I'm just new in flutter and I think this is a newbie question.

I'm trying to get the data that I call on my API and save it to my model but it's having an error type 'List' is not a subtype of type 'Map<dynamic, dynamic>'

Here is the copy of my model

class AdTemplate{
  final int id; 
  final String filePath; 
  final String notification; 
  final String status; 
  final int whenAdded; 

  AdTemplate(
      {this.id, 
      this.filePath, 
      this.notification,
      this.status, 
      this.whenAdded});

  factory AdTemplate.fromJson(Map<String, dynamic> json) {
    return  AdTemplate(
      id: json['ID'], 
      filePath: json['FilePath'],
      notification: json['Notification'], 
      status: json['Status'], 
      whenAdded: json['WhenAdded']
    );
  }
}

And this is my function

Future<AdTemplate> getActiveBannerNotif() async {  
    try { 
      String url = 'https://api/path/'; 
      var res = await http.get(url);  
      final Map data = convert.jsonDecode(res.body);

      if (res.statusCode == 200) { 
        print("Data Fetch!");    
        AdTemplate template = AdTemplate.fromJson(data);  

        return template;
      } else {
        print('No data.'); 

        return null;
      }
    } catch (e) {
      print(e);
      return null;
    } 
}

This is the sample data that I get from the API

[{"ID":49,"FilePath":"20210903t171244.png","Notification":"ACT","WhenAdded":1630689165,"Status":"INA"}]

CodePudding user response：

API returns JSON array not json object so that is List not Map.

try :

if (res.statusCode == 200) { 
    print("Data Fetch!");    
    AdTemplate template = AdTemplate.fromJson(json.decode(utf8.decode(res.bodyBytes)));  

    return template;
  }

CodePudding user response：

You are receiving an array from your API and that causes the error. change as following to access a single element from array

Future<AdTemplate> getActiveBannerNotif() async {  
    try { 
      String url = 'https://api/path/'; 
      var res = await http.get(url);  
      
      if (res.statusCode == 200) { 
        print("Data Fetch!");  
        final data = convert.jsonDecode(res.body);
        AdTemplate template = AdTemplate.fromJson(data[0]);  

        return template;
      } else {
        print('No data.'); 

        return null;
      }
    } catch (e) {
      print(e);
      return null;
    } 
}