yaml2podo 0.1.17

The `yaml2podo` is a generator and utility (all in one) that generates PODO classes to convert between JSON and Dart objects

yaml2podo

The yaml2podo is a generator and utility (all in one) that generates PODO classes to convert between JSON and Dart objects

Version 0.1.17

Example of use.

Declarations (simple enough and informative).

example/json_objects.yaml

Messages:
  messages : List<Iterable<String>>
ObjectWithMap:
  products: Map<String, Product>
Order:  
  date: DateTime
  items: List<OrderItem>
  amount: double
OrderItem:
  product: Product
  quantity.qty: int
  price: double  
Product:
  name: String
  id: int

Run utility.

pub global run yaml2podo example/json_objects.yaml

Generated code does not contain dependencies and does not import anything. The same source code that you would write with your hands. Or at least very close to such a code.

example/json_objects.dart

// Generated by 'yaml2podo'
// Version: 0.1.17
// https://pub.dev/packages/yaml2podo

class Messages {
  final List<Iterable<String>> messages;

  Messages({this.messages});

  factory Messages.fromJson(Map map) {
    return Messages(
        messages:
            _toList(map['messages'], (e) => _toList(e, (e) => e as String)));
  }

  Map<String, dynamic> toJson() {
    var result = <String, dynamic>{};
    result['messages'] = _fromList(messages, (e) => _fromList(e, (e) => e));
    return result;
  }
}

class ObjectWithMap {
  final Map<String, Product> products;

  ObjectWithMap({this.products});

  factory ObjectWithMap.fromJson(Map map) {
    return ObjectWithMap(
        products: _toMap(map['products'], (e) => Product.fromJson(e as Map)));
  }

  Map<String, dynamic> toJson() {
    var result = <String, dynamic>{};
    result['products'] = _fromMap(products, (e) => e.toJson());
    return result;
  }
}

class Order {
  final double amount;
  final DateTime date;
  final List<OrderItem> items;

  Order({this.amount, this.date, this.items});

  factory Order.fromJson(Map map) {
    return Order(
        amount: _toDouble(map['amount']),
        date: _toDateTime(map['date']),
        items: _toList(map['items'], (e) => OrderItem.fromJson(e as Map)));
  }

  Map<String, dynamic> toJson() {
    var result = <String, dynamic>{};
    result['amount'] = amount;
    result['date'] = _fromDateTime(date);
    result['items'] = _fromList(items, (e) => e.toJson());
    return result;
  }
}

class OrderItem {
  final double price;
  final Product product;
  final int quantity;

  OrderItem({this.price, this.product, this.quantity});

  factory OrderItem.fromJson(Map map) {
    return OrderItem(
        price: _toDouble(map['price']),
        product: _toObject(map['product'], (e) => Product.fromJson(e as Map)),
        quantity: map['qty'] as int);
  }

  Map<String, dynamic> toJson() {
    var result = <String, dynamic>{};
    result['price'] = price;
    result['product'] = product?.toJson();
    result['qty'] = quantity;
    return result;
  }
}

class Product {
  final int id;
  final String name;

  Product({this.id, this.name});

  factory Product.fromJson(Map map) {
    return Product(id: map['id'] as int, name: map['name'] as String);
  }

  Map<String, dynamic> toJson() {
    var result = <String, dynamic>{};
    result['id'] = id;
    result['name'] = name;
    return result;
  }
}

String _fromDateTime(dynamic data) {
  if (data == null) {
    return null;
  }
  if (data is DateTime) {
    return data.toIso8601String();
  }
  return data as String;
}

List _fromList(dynamic data, dynamic Function(dynamic) toJson) {
  if (data == null) {
    return null;
  }
  var result = [];
  for (var element in data) {
    var value;
    if (element != null) {
      value = toJson(element);
    }
    result.add(value);
  }
  return result;
}

Map<String, dynamic> _fromMap(dynamic data, dynamic Function(dynamic) toJson) {
  if (data == null) {
    return null;
  }
  var result = <String, dynamic>{};
  for (var key in data.keys) {
    var value;
    var element = data[key];
    if (element != null) {
      value = toJson(element);
    }
    result[key.toString()] = value;
  }
  return result;
}

DateTime _toDateTime(dynamic data) {
  if (data == null) {
    return null;
  }
  if (data is String) {
    return DateTime.parse(data);
  }
  return data as DateTime;
}

double _toDouble(dynamic data) {
  if (data == null) {
    return null;
  }
  if (data is int) {
    return data.toDouble();
  }
  return data as double;
}

List<T> _toList<T>(dynamic data, T Function(dynamic) fromJson) {
  if (data == null) {
    return null;
  }
  var result = <T>[];
  for (var element in data) {
    T value;
    if (element != null) {
      value = fromJson(element);
    }
    result.add(value);
  }
  return result;
}

Map<K, V> _toMap<K extends String, V>(
    dynamic data, V Function(dynamic) fromJson) {
  if (data == null) {
    return null;
  }
  var result = <K, V>{};
  for (var key in data.keys) {
    V value;
    var element = data[key];
    if (element != null) {
      value = fromJson(element);
    }
    result[key.toString() as K] = value;
  }
  return result;
}

T _toObject<T>(dynamic data, T Function(dynamic) fromJson) {
  if (data == null) {
    return null;
  }
  return fromJson(data);
}

/*
Messages:
  messages : List<Iterable<String>>
ObjectWithMap:
  products: Map<String, Product>
Order:  
  date: DateTime
  items: List<OrderItem>
  amount: double
OrderItem:
  product: Product
  quantity.qty: int
  price: double  
Product:
  name: String
  id: int
*/

And, of course, an example of using code.

example/example.dart

import 'json_objects.dart';

void main() {
  // Order
  var products = _getProducts();
  var items = _creataOrderItems(products);
  var order = Order(
      amount: _calculateAmount(items),
      date: DateTime(2019, 05, 31),
      items: items);
  var jsonOrder = order.toJson();
  print(jsonOrder);
  order = Order.fromJson(jsonOrder);
  // Messages
  var messages = Messages(messages: []);
  messages.messages.add(['Hello', 'Goodbye']);
  messages.messages.add(['Yes', 'No']);
  var jsonMessages = messages.toJson();
  print(jsonMessages);
  // ObjectWithMap
  var objectWithMap = ObjectWithMap(products: {});
  for (var product in products) {
    objectWithMap.products[product.name] = product;
  }

  var jsonObjectWithMap = objectWithMap.toJson();
  print(jsonObjectWithMap);
  objectWithMap = ObjectWithMap.fromJson(jsonObjectWithMap);
}

List<OrderItem> _creataOrderItems(List<Product> products) {
  var result = <OrderItem>[];
  for (var i = 0; i < products.length; i++) {
    var product = products[i];
    var orderItem =
        OrderItem(price: 10.0 + i, product: product, quantity: i + 1);
    result.add(orderItem);
  }

  return result;
}

double _calculateAmount(List<OrderItem> items) {
  var result = 0.0;
  for (var item in items) {
    result += item.quantity * item.price;
  }

  return result;
}

List<Product> _getProducts() {
  var result = <Product>[];
  for (var i = 0; i < 2; i++) {
    var product = Product(id: i, name: 'Product $i');
    result.add(product);
  }

  return result;
}

Result:

{amount: 32.0, date: 2019-05-31T00:00:00.000, items: [{price: 10.0, product: {id: 0, name: Product 0}, qty: 1}, {price: 11.0, product: {id: 1, name: Product 1}, qty: 2}]}
{messages: [[Hello, Goodbye], [Yes, No]]}
{products: {Product 0: {id: 0, name: Product 0}, Product 1: {id: 1, name: Product 1}}}

How to install utility yaml2podo?

Run the following command in the terminal

pub global activate yaml2podo