class ImgModel { String url; String size; double longs; double paragraph; int sort; double get aspect => paragraph / longs; ImgModel({this.url, this.size, this.longs, this.paragraph, this.sort}); ImgModel.fromJson(Map json) { url = json['url']; size = json['size']; longs = json['longs'] + .0; paragraph = json['paragraph'] + .0; sort = json['sort']; } static String first(List models) { if (models == null) return ''; if (models.isEmpty) return ''; return models.first.url ?? ''; } static ImgModel firstModel(List models) { if (models == null) return null; if (models.isEmpty) return null; return models.first; } Map toJson() { final Map data = new Map(); data['url'] = this.url; data['size'] = this.size; data['longs'] = this.longs; data['paragraph'] = this.paragraph; data['sort'] = this.sort; return data; } }