json Pub Package

Example

// 0x00 import package
import 'package:g_json/g_json.dart';
...
void someMethod() {
 final jsonStr = '''
 {
 "_id": "5f0fd54e54044a55385a0f31",
 "name": {
 "first": "Coleman",
 "last": "Evans"
 },
 "range": [0, 1, 2, 3, 4, 5, 6,7, 8, 9],
 "friends": [
 {
 "id": 0,
 "name": "Gibson Hull"
 },
 {
 "id": 1,
 "name": "Dunlap Bush"
 },
 {
 "id": 2,
 "name": "Bette Herman"
 }
 ]
 }
 ''';
 // 0x01 parse json string to object
 final mode = JSON.parse(jsonStr);
 final _id = mode['_id'].stringValue;
 final secondFriend = mode[['friends', 2]]['name'].stringValue;
 print(mode.prettyString());
}

Initialization

import 'package:json/json.dart';
final model = JSON(jsonMap);
// or
final model = JSON.parse(jsonString);

Subscript

// Getting a string from a JSON Array
final name = json[0].stringValue;

// Getting an array of string from a JSON Array
final names = json.arrayValue.map((j) => j['name'].stringValue)

// Getting a string using a path to the element
final path = [1, 'list', 2, 'name'];
final name = json[path].string;
// or
final name = json[[1, 'list', 2, 'name']].string;
// Just the same
final name = json[1]['list'][2]['name'].string;

Error

final json = JSON(['name', 'age']);
final name = json[3].string;
if (name != null) {
 // Do something you want
} else {
 print(json[3].error); // List(3) Index is out of bounds.
}

final json = JSON({'name': name, 'age': 20});
final address = json['address'].string;
if (address != null) {
 // Do something you want
} else {
 print(json['address'].error); // "Map["address"] does not exist"
}

final json = JSON.nil;
print(json[0]); // List(0) failure, It is not a List
print(json[0].error); // List(0) failure, It is not a List
print(json['key']); // Map(key) failure, It is not a Map
print(json['key'].error); // Map(key) failure, It is not a Map

Optional getter

// num
final count = json['user']['favourites_count'].num;
if (count != null) {
 // DO something
} else {
 print(json['user']['favourites_count'].error);
}
// String
final name = json['user']['favourites_name'].string;
if (name != null) {
 // DO something
} else {
 print(json['user']['favourites_name'].error);
}
// Bool
final isTranslator = json['user']['is_translator'].bool;
if (isTranslator != null) {
 // DO something
} else {
 print(json['user']['is_translator'].error);
}
...

Non-optional getter

// if not a Number or nil, return 0
int id = json['id'].integerValue;
// if not a string or nil, return ''
String name = json['name'].stringValue;
// if not a list or nil return []
List<JSON> list = json['list'].listValue;
// if not a map or nil, return {}
Map<String, JSON> map = json['map'].mapValue;

Setter

json['name'] = 'G_JSON';
json[0] = 1;

Raw object && convert to jsonString

// raw
final value = json.value;
// json string
final jsonString = json.rawString();

Dynamic member

dynamic person = JSON({'name': 'kevin', 'language': 'dart'});
person.name = 'icey';
person.language = 'Swift';
print(person.rawString()); // {"name": "icey", "language": "swift"}