flutter json_serializable tojson does not work properly

Question

Im looking into the Order class example and found that the Item class is not converted to Map.

class Order {
  int count;
  int itemNumber;
  bool isRushed;
  Item item; 
  Map<String, dynamic> toJson() => _$OrderToJson(this);
}

The generated .g file has this:

Map<String, dynamic> _$OrderToJson(Order instance) {
  ...
  writeNotNull('item', instance.item);
  ...
  return val;
}

The item in order map is still of Item type, but Im expecting it to be auto converted to Map as well. the generated .g file should has something like this

writeNotNull('item', instance.item.toJson());

I don't want to manually add this since it will be overwritten when .g file is regenerated. Why is the json_serializable lib not doing such a simple thing, or am I missing something? thanks.

Panda World · Accepted Answer · 2018-11-27 10:23:34Z

21

Now I found the solution, just set this in build.yaml

explicit_to_json = true.

and regenerate the .g file. It should convert it to Map for you now.

answered Nov 27, 2018 at 10:23

Panda World

2,0262 gold badges24 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

aaronvargas · Accepted Answer · 2019-05-11 00:54:02Z

8

For firebase you'll want the any_map option also since the maps from firebase are <dynamic, dynamic> otherwise it will expect <String, dynamic>

Create this file as build.yaml in the root of your flutter project, it doesn't exist by default.

targets:
  $default:
    builders:
      json_serializable:
        options:
          any_map: true
          explicit_to_json: true

answered May 11, 2019 at 0:54

aaronvargas

14.3k3 gold badges55 silver badges54 bronze badges

1 Comment

Ced Over a year ago

why is the explicit_to_json needed ? Why is the default false ?

boformer · Accepted Answer · 2018-11-24 14:26:19Z

2

json.encode(...) will attempt to find a toJson() method on the Item class, and serialize the item correctly. There is no need for the generated serialization logic to call toJson().

You just have to make sure that the Item class is also annotated with @JsonSerializable() and implements toJson().

Also, you would never call toJson() manually, instead you pass your order object to json.encode(...)

answered Nov 24, 2018 at 14:26

boformer

30.3k10 gold badges87 silver badges71 bronze badges

2 Comments

Panda World Over a year ago

thanks for your reply @boformer, i do understand encode will convert it correctly but what im looking for is a returned map whereas encode returns a json String. the firestore lib that Im using expect the datas to be of Map type, so I will have to use decode again to convert it back to Map type. I think if .g file should use instance.item.toJson() to save us the extra effort.

boformer Over a year ago

In that case you probably have to write the serialization code yourself

Dhaval Kansara · Accepted Answer · 2023-01-16 15:05:22Z

2

Please add the below line above your child-level data model class... So it will call in dept toJson method of each model...

@JsonSerializable(explicitToJson: true)

answered Jan 16, 2023 at 15:05

Dhaval Kansara

3,9716 gold badges26 silver badges52 bronze badges

Collectives™ on Stack Overflow

flutter json_serializable tojson does not work properly

4 Answers 4

Comments

1 Comment

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

1 Comment

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related