More than one field has the JSON key `item`. about json_serializable.dart HOT 9 CLOSED

We recently added fromJson, toJson properties to JsonKey that let you provide methods to handle conversion yourself. You could detect if the value is a list or a single value and populate the property accordingly.

from json_serializable.dart.

Thanks, I appreciate the clarification. I know this isn't a help forum, but for the life of me I can't figure out what syntax I need to use with the fromJson and there isn't really any documentation for those functions. You mind helping me understand how I can use fromJson to handle either a list or a single item in the following case?

@JsonKey(name: 'book',)
 final List<Book> books;

 BooksContainer(
     this.books,
     );

from json_serializable.dart.

Something like

List<Book> _decodeBooks(Object input) {
  // your code here
}

class MyClass {
  @JsonKey(name: 'book', fromJson: _decodeBooks)
  final List<Book> books;
}

from json_serializable.dart.

from json_serializable.dart.

from json_serializable.dart.

I don't want to hastily open another issue. Yet after implementing fromJSON, debugging and running from Android Studio works fine, but release builds give a type mismatch error in my fromJSON method.

06-16 10:23:59.541 6695 6712 E flutter : [ERROR:topaz/lib/tonic/logging/dart_error.cc(16)] Unhandled exception:
06-16 10:23:59.541 6695 6712 E flutter : type '_OneByteString' is not a subtype of type 'int' of 'index'
06-16 10:23:59.541 6695 6712 E flutter : #0 _GrowableList.[] (dart:core/runtime/libgrowable_array.dart:0)

Is there a problem in my code or is this an actual issue?

The offending method is below and here is the repository: https://github.com/fatherchill/world_liturgy_app/tree/CalendarAndCollects

List<dynamic> _decodePrayerBookorService(itemOrList){
//  debugPrint(itemOrList);
  print('begin decode Prayerbook or Service');

  List<dynamic> list = [];
  if (itemOrList == null){
    return null;
  }
  if (itemOrList.runtimeType.toString() == 'List<dynamic>'){
    list = itemOrList;
  }else{
    list.add(itemOrList);
  }

  print(list.toString().substring(0,20));

  if (list.first['service'] != null){
    return list.map((e) =>
    e == null ? null : new PrayerBook.fromJson(e as Map<String, dynamic>))
        ?.toList();
  }else if (list.first['section'] != null){
    return list.map((e) =>
    e == null ? null : new Service.fromJson(e as Map<String, dynamic>))
        ?.toList();
  }else{
    return null;
  }

}

from json_serializable.dart.

List<dynamic> list = [];
  if (itemOrList == null){
    return null;
  }
  if (itemOrList.runtimeType.toString() == 'List<dynamic>'){
    list = itemOrList;
  }else{
    list.add(itemOrList);
  }

Don't do that!

  if (itemOrList == null){
    return null;
  }
  List list;
  if (itemOrList.runtimeType.toString() == 'List<dynamic>'){
    list = itemOrList;
  }else{
    list = [itemOrList];
  }

Not sure if that'll help...but it's better...

from json_serializable.dart.

from json_serializable.dart.

For anyone else coming to this issue due to: More than one field has the JSON key for name <name>, you might be in this situation

class MyClass 
{
  SomeType A;

  @JsonKey(name: 'A')
  SomeType B;
}

It is possible if you are trying to rename a field on deserialization. You can solve it like this:

class MyClass 
{
  @JsonKey(ignore: true)
  SomeType A;

  @JsonKey(name: 'A')
  SomeType B;
}

from json_serializable.dart.