conduit_codable

Description:

conduit codable

codable #

A library for encoding and decoding dynamic data into Dart objects.
Basic Usage #
Data objects extend Coding:
class Person extends Coding {
String name;

@override
void decode(KeyedArchive object) {
// must call super
super.decode(object);

name = object.decode("name");
}

@override
void encode(KeyedArchive object) {
object.encode("name", name);
}
}
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An object that extends Coding can be read from JSON:
final json = json.decode(...);
final archive = KeyedArchive.unarchive(json);
final person = Person()..decode(archive);
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Objects that extend Coding may also be written to JSON:
final person = Person()..name = "Bob";
final archive = KeyedArchive.archive(person);
final json = json.encode(archive);
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Coding objects can encode or decode other Coding objects, including lists of Coding objects and maps where Coding objects are values. You must provide a closure that instantiates the Coding object being decoded.
class Team extends Coding {

List<Person> members;
Person manager;

@override
void decode(KeyedArchive object) {
super.decode(object); // must call super

members = object.decodeObjects("members", () => Person());
manager = object.decodeObject("manager", () => Person());
}

@override
void encode(KeyedArchive object) {
object.encodeObject("manager", manager);
object.encodeObjects("members", members);
}
}
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Dynamic Type Casting #
Types with primitive type arguments (e.g., List<String> or Map<String, int>) are a particular pain point when decoding. Override castMap in Coding to perform type coercion.
You must import package:codable/cast.dart as cast and prefix type names with cast.
import 'package:codable/cast.dart' as cast;
class Container extends Coding {
List<String> things;

@override
Map<String, cast.Cast<dynamic>> get castMap => {
"things": cast.List(cast.String)
};


@override
void decode(KeyedArchive object) {
super.decode(object);

things = object.decode("things");
}

@override
void encode(KeyedArchive object) {
object.encode("things", things);
}
}

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Document References #
Coding objects may be referred to multiple times in a document without duplicating their structure. An object is referenced with the $key key.
For example, consider the following JSON:
{
"components": {
"thing": {
"name": "The Thing"
}
},
"data": {
"$ref": "#/components/thing"
}
}
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In the above, the decoded value of data inherits all properties from /components/thing:
{
"$ref": "#/components/thing",
"name": "The Thing"
}
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You may create references in your in-memory data structures through the Coding.referenceURI.
final person = Person()..referenceURI = Uri(path: "/teams/engineering/manager");
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The above person is encoded as:
{
"$ref": "#/teams/engineering/manager"
}
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You may have cyclical references.
See the specification for JSON Schema and the $ref keyword for more details.