ko.mapping.fromJS后，ComputedObservables不会重新计算

Question

I'm using KnockoutJS and I have a nested ViewModel-Structure with Computed Observables on each level. The parent levels contains totalization of it's children. The datastructure looks like this (simplyfied):

vm.clientsRawData = [
    {
        ClientName: "Thomas",
        MoneyAccounts: [
            {
                Currency: "USD",
                Amount: "1000"
            }
            {
                Currency: "EUR",
                Amount: "2000"
            }
        ]
    },
    {
        ClientName: "Ann",
        MoneyAccounts: [
            {
                Currency: "CHF",
                Amount: "4000"
            }
            {
                Currency: "EUR",
                Amount: "1500"
            }
        ]
    }
]

After initializing the ViewModel (using ko.mapping.fromJS) I saw that the ComputedObservables on the "Top-Level (for instance, vm.AllUsd(), containing the Sum of each clients Usd MoneyAccounts)" didn't refresh. The Sum is still 0. What do i have to do to Calculate this total amounts within the Mapping of the JS-Structure?

I've already tried to achieve this with dummy-observables, but this extremely slows down the Loading-Process (Browser overwhelmed, hanging up)

Thanks in advance

UPDATED: For instance, this example. I found out, that the Client-Count is 0 after inizialization. But why?

var ClientsMapping = {
  create: function (options) {
    var client = ko.mapping.fromJS(options.data, ContainersMapping)
    //Some computed observables for level one here...
    return client;
  }
}
var ContainersMapping = {
  'Containers': {
    create: function (options) {
      var container = ko.mapping.fromJS(options.data, MoneyAccountsMapping)
      container.totalChf = ko.computed(function () {
        var total = 0;
        $.each(container.MoneyAccounts(), function () {
          if (this.Currency() == "CHF") {
            total += this.Amount();
          }
        })
        return total;
      })
      //Some computed observables for level two here...
      return container;
    }
  }
}

var MoneyAccountsMapping = {
  'MoneyAccounts': {
    create: function (options) {
      var macc = new MoneyAccountModel(options.data)
      //Some computed observables for level three here...
      return macc;
    }
  }
}
var ClientModel = function (data) {
  ko.mapping.fromJS(data, {}, this);
}
var ContainerModel = function (data) {
  ko.mapping.fromJS(data, {}, this);
}
var MoneyAccountModel = function (data) {
  ko.mapping.fromJS(data, {}, this);
}
var data = [
  {
    'Clients': 'Thomas',
    'Containers': [
      {
        'ContName': 'Cont01',
        'MoneyAccounts': [
          { Currency: "CHF", Amount: 1000 },
        ]
      }
    ]
  },
{
  'Clients': 'Ann',
  'Containers': [
    {
      'ContName': 'Cont01',
      'MoneyAccounts': [
        { Currency: 'CHF', Amount: 1000 },
        { Currency: 'EUR', Amount: 500 }
      ]
    }
  ]
}
]

function viewModel() {
  var self = this;
  self.clients = ko.observableArray()
  self.clientsCount = ko.computed(function () {
    return self.clients().length
  })
}
var vm;
$(function () {
  vm = new viewModel();
  vm.clients = ko.mapping.fromJS(data, ClientsMapping);
})

Answer 1

Ok, got it. I had to call the clients observableArray like this:

vm.clients(ko.mapping.fromJS(data, ClientsMapping)())

Many thanks Eric for pointing me to the right direction. You saved me! :-)