Parse a JSON file using class in Flutter - arrays

Question

I have a following problem. I just cannot understand what can be the easiest way to parse an information from JSON to an array of objects in flutter.
I have a following class:
class Organization {
String subject;
String organization;
String shortDescription;
String address;
String phoneNumber;
String contactInfo;
List<String> tags;
Organization({
this.subject,
this.organization,
this.shortDescription,
this.address,
this.phoneNumber,
this.contactInfo,
this.tags,
});
Organization.fromJson(Map<String, dynamic> json) {
subject = json['Subject'];
organization = json['Organization'];
shortDescription = json['Short description'];
address = json['Address'];
phoneNumber = json['Phone number'];
contactInfo = json['Contact info'];
tags = json['Tags'].cast<String>();
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['Subject'] = this.subject;
data['Organization'] = this.organization;
data['Short description'] = this.shortDescription;
data['Address'] = this.address;
data['Phone number'] = this.phoneNumber;
data['Contact info'] = this.contactInfo;
data['Tags'] = this.tags;
return data;
}
}
This is the small sample of Json file that I have in assets folder.
[
{
"Subject": "Cultuur - Culture ",
"Organization": "Museum aan de stroom ",
"Short description": "The MAS is a museum that provides you with permanent and temporary exhibitions. These offer a refreshing look at the city and it's history. At the top, on the tenth floor, you can enjoy a 360-degree panorama of the city, the port and the river.",
"Address": "Hanzestedenplaats 1, 2000 Antwerpen",
"Phone number": "[phone]",
"Contact info": "www.mas.be",
"Tags": ["Meeting place", "Museum", "Antwerp", "Art"]
},
{
"Subject": "Cultuur - Culture ",
"Organization": "Red star line museum ",
"Short description": "Through personal story's of immigrants the Red star line museum paints a picture of the immigration history in Antwerp. ",
"Address": "Montevideostraat 3, 2000 Antwerpen",
"Phone number": "[phone]",
"Contact info": "www.redstarline.be",
"Tags": ["Museum", "Antwerp", "History", "Immigration"]
}
]
I am just trying to parse information from this file to a list of Organisations as presented below:
List<Organisation> organisations = [];
Future<void> readJson() async {
final String response =
await rootBundle.loadString('assets/organisations.json');
final data = await json.decode(response);
organisations = data;
}
However I get Unhandled Exception: type List dynamic is not a subtype of type List Organisation error.
In my opinion data should be an array of my objects. What am I doing wrong? Or maybe is there simpler method to achieve this result?

Answer 1

At the final of readJson función, you can call Organization.fromJson like this:
Future<void> _readJson() async {
final String response =
await rootBundle.loadString('assets/data/organizations.json');
final List<dynamic> data = await json.decode(response);
for (dynamic it in data) {
final Organization organization = Organization.fromJson(it); // Parse data
organizations.add(organization); // and organization to List
}
}