Typewriter

Typewritter is a Dart library for generating codecs, encoder/decoder pairs for serialization. Serialization code is repetitive and time consuming to write. Instead of using reflection/mirrors, Typewriter enables developers to generate configurable codecs automatically from Dart source code.

The supported target languages are

• JSON
• XML (partial)
• Yaml (planned)

This library is currently under active development and is not stable enough for non-experimental use.

Example Usage

Typewriter annotations configure the behavior of the generated codecs. For example, the following Class uses a JsonKey annotation, which changes the name of the field on the resulting JSON.

@deriveJson()
class Person {
  int age;
  @jsonProperty('birth_day')
  DateTime birthDay;
  String name;
  Cat myCat;
}

@deriveJson()
class Cat {
  String name;
}

An instance of this class serialized to JSON would look something like the following.

{ "age": 25, "birth_day": "some-long-iso-string", "name": "Jonah", "myCat": {"name": "Mike Hat"}}

Xml annotations support configuring the names of elements and child elements with XmlElement. The annotation XmlAttribute allows developers to place annotations on any of the elements in the class.

@deriveXml()
class ApiResponse {
  @xmlElement('name-list', 'name')
  List<String> names;
  
  @xmlAttribute('name-length', element: 'name-list')
  int length;
}

The following is an instance of ApiResponse serialized to XML. Typewriter also handles the xml header.

<?xml version="1.0"?>
<ApiResponse>
  <name-list length="3">
    <name>Peter Parker</name>
    <name>Bruce Wayne</name>
    <name>Snoop Dogg</name>
  </name-list>
</ApiResponse>