Provide default value in JsonKey and use that instead of throwing type cast error

[rbresjer]

If for some reason an API returns another type than expected, you get an (e.g.) type '_GrowableList<dynamic>' is not a subtype of type 'Map<String, dynamic>?' in type cast error. I know you can use checked: true to get an exception instead of an error, but I'd like to use a default fallback value and fail silently. Is this easily achievable?

E.g. @JsonSerializable(useDefaultIfError: true) and @JsonKey(useDefaultIfError: true) which falls back to the defaultValue or null if the value cannot be initialised from the JSON.

[hm-arora]

I had faced the similar kind of problem #899, I tweaked the library to handled my case. I'll try to build this type of config, maybe it will help other people also

[tvqphong001]

I have same problem when json['listSample'] return null, your code json['listSample'] as List<dynamic> throw exception

[kevmoo]

You could always use a custom converter to accomplish this. Put the try/catch logic in the converter.

[deniskrr]

@Himanshuarora97, could you show us a sample code for achieving this?

[deniskrr]

@kevmoo , can we have a single converter covering all types or should we create one for each possible type?

[kevmoo]

If you have many target types you'll need many functions. One for each value

[deniskrr]

I see... I thought we could do some generics magic as I'm really just looking for try { parse } catch { return default }—so the type is irrelevant.