Flutter model for nested json

Question

I'm creating a flutter app for data visualization. There will be 3 pages:

• Filter page for filter criteria,
• List page for visualizing serach result,
• Details page.

I will receive a json like this:

data.json

[
    {
        "name": "Jhon",
        "surname": "Walker",
        "details": "{\"work\":{\"salary\":\"116\",\"company\":\"evolution\",\"image\":\"http://image.jpg\"},\"address\":{\"street\":\"grand station\",\"city\":\"salt lake\"}}"    
    },
    {
        "name": "Alan",
        "surname": "Turing",
        "details": "{\"work\":{\"salary\":\"116\",\"company\":\"evolution\",\"image\":\"http://image.jpg\"},\"address\":{\"street\":\"grand station\",\"city\":\"salt lake\"}}"    
    }
]

It could be a really long list.

I have already posted a question here about my code for this app which is not working, here is the discussion

Flutter app error

So now I' m asking a different question. Which is the best model for this json structure? I need to have direct access to all the fields in the details object. I would like to have the ability to directly get the field salary or company. I need to have access to the image field which will contain a url for an image to display in the app. In the linked post I have generated a model using serialization and built_value. It is not working in the code, I still get the error:

type String is not a subtype of type 'Map<String, dynamic>' in type cast

And no one solutions that I find online seems to work.

I have created another model without nested objects, this is how I made it: model.dart

class User {

  String name;

  String surname;

  String details;


  User({
    this.name,
    this.surname,
    this.details,
  });


  factory User.fromJson(Map<String, dynamic> json) => User(
    name: json["name"],
    surname: json["surname"],
    details: json["details"],
  );

  Map<String, dynamic> toJson() => {
    "name": name,
    "surname": surname,
    "details": details,
  };
}

With this model I' m able to display the data on a ListView but the details field is one only big string and I have no idea about how to access the fields in the details object. I can only think to regualr expression but it sounds kind of tricky, and why I should use regualr expression when I have JSON?

Which model is the best for this json? Should I change path? Do you have any advice for a better data model, or maybe a solution for using the data model correctly from the discussion that I linked? I' m not asking the same question, I' m just trying to find the right solution for accessing deatils fields using standard json.

Thank you!

Answer 1

Please refer to this link to get the model for your json.

https://app.quicktype.io/

Add your json, select your language and you can have your model.