firebase - 如何将列表作为参数发送到Flutter中的Firebase函数？

Question

我想知道如何使用Cloud Functions Plugin for Flutter发送或发布地图列表。
我有一些这样的地图：

var customer1 = {'name':'tom','lastname':'smith'}; 
var customer2 = {'name':'bob','lastname':'lee'}; 
var customer3 = {'name':'george','lastname':'collins'};

这些地图后来成为一个列表：
var _customerList = [customer1, customer2, customer3];
我正在尝试将此列表作为参数发送或发布到云函数中，以便进行如下颤振：

   var _data = {
      'customerList': _customerList,
    };

    final HttpsCallable callable = CloudFunctions.instance
        .getHttpsCallable(functionName: 'createCustomer')
      ..timeout = const Duration(seconds: 30);

    final HttpsCallableResult result = await callable.call(_data);

但是，我得到这个错误：
I/flutter (11486): Invalid argument: Instance of ...
如果我尝试发布一个简单的字符串，一切都会正常工作。不过，我似乎没有正确地张贴地图列表。
我正在使用此版本的插件：

dependencies:
  cloud_functions: ^0.3.0+1

谢谢你的帮助。

Answer 1

将复杂数据结构序列化/反序列化为JSON对象的简单方法是使用包
marshalling
原型（使用“yaml”格式）
json_对象.yaml

Customer:
  name: String
  lastname: String  
CustomerList:
  customerList: List<Customer>

自动生成代码（使用实用程序“yaml2podo”）。
pub global run marshalling:yaml2podo json_objects.yaml
json_objects.dart

// Generated by tool.

import 'package:marshalling/json_serializer.dart';

final json = JsonSerializer()
  ..addType(() => Customer())
  ..addType(() => CustomerList())
  ..addIterableType<List<Customer>, Customer>(() => <Customer>[])
  ..addAccessor('customerList', (o) => o.customerList, (o, v) => o.customerList = v)
  ..addAccessor('lastname', (o) => o.lastname, (o, v) => o.lastname = v)
  ..addAccessor('name', (o) => o.name, (o, v) => o.name = v)
  ..addProperty<Customer, String>('name')
  ..addProperty<Customer, String>('lastname')
  ..addProperty<CustomerList, List<Customer>>('customerList');

class Customer {
  String name;
  String lastname;

  Customer();

  factory Customer.fromJson(Map map) {
    return json.unmarshal<Customer>(map);
  }

  Map<String, dynamic> toJson() {
    return json.marshal(this) as Map<String, dynamic>;
  }
}

class CustomerList {
  List<Customer> customerList;

  CustomerList();

  factory CustomerList.fromJson(Map map) {
    return json.unmarshal<CustomerList>(map);
  }

  Map<String, dynamic> toJson() {
    return json.marshal(this) as Map<String, dynamic>;
  }
}

使用生成的代码（自动序列化/反序列化对象）

import 'json_objects.dart';

void main() {
  var customers = <Customer>[];
  var customer = Customer()
    ..name = 'tom'
    ..lastname = 'smith';
  customers.add(customer);
  customer = Customer()
    ..name = 'bob'
    ..lastname = 'lee';
  customers.add(customer);
  customer = Customer()
    ..name = 'george'
    ..lastname = 'lee';
  customers.add(customer);
  var customerList = CustomerList();
  customerList.customerList = customers;
  var data = customerList.toJson();
  // final HttpsCallableResult result = await callable.call(data);
  print(data);
}

结果：
{customerList: [{name: tom, lastname: smith}, {name: bob, lastname: lee}, {name: george, lastname: lee}]}