Add option to omit null fields in fromJson constructor or define default values

[AlexanderJohr]

Great Library. Finally something to replace Dartson with. However: When deserializing fields that aren't in the json, they will be written to the object as null. In Angular I then get errors like "boolean expression must not be null". I would like to keep the default values assigned to the fields instead of having those overwritten by null:

// Please keep my assigned value, don't overwrite with null
bool myBool = true

Or maybe setting the default value with an annotation would be useful.

@JsonKey(default: true)
bool myBool

[kevmoo]

@AlexanderJohr – FYI, going to look into this soon...

Something we want for other things. @jakemac53 FYI

[jakemac53]

+1 for an annotation, and possibly a warning if it sees a default value for a constructor parameter that it knows its going to overwrite with (possibly) null?

[AlexanderJohr]

Awesome!

[kevmoo]

Published, @AlexanderJohr – let us know how it goes...

[AlexanderJohr]

@kevmoo Works just great! Now I can remove all those factory constructors which ensured my default values before.

[kevmoo]

👍

[Nico04]

In my projects, several of my classes inherits this class :

abstract class Editable {
  DateTime updatedAt;

  Editable() : updatedAt = DateTime.now();
} 

The idea is to store the date when the objet was created.
It works great when a create objets from my code.
But if the objetc is created from a json (via fromJson), and because the json doesn't include updatedAt, updateAt is overriten with null, which is unwanted.

Setting the default value with @jsonkey(defaultValue: ...) is not enought because if the object is created not from a json, it doens't get his default value...

Any idea ?

[kevmoo]

@Nico04 – this is tough.

You could create get/set pairs with a private field and ignore null values on set to updatedAt.