将select2与剔除绑定

我是淘汰赛的新手，试图让我的select2在淘汰赛绑定中表现出色.

I'm new to knockout and trying to get my select2 to play nicely with my knockout bindings.

我要做的就是将帐户数组绑定到我的select2上(这可行)，然后 绑定发生时设置初始值.我出于某种原因无法正常工作.还注意到init和update函数最初是被调用的，但是每当我更改select2下拉列表的值时，更新函数都不会被触发.

All I want to do is bind accounts array to my select2 (this works) and then have the initial value set when the binding occurs. I for some reason can not get this to work. Also noticed that the init and update function get called initially, but anytime I change the value of the select2 dropdown, the update function is not being triggered.

任何帮助将不胜感激.

HTML

 <div class="col-sm-12 col-md-3">
   <fieldset class="form-group">
     <label data-bind="attr:{for:'job'+laborDetailId()}">Job</label>
     <select class="select2" data-bind="attr:{id:'job'+laborDetailId()},updateaccountdropdown: {value:account(),data:accounts,width:'100%'}">
     </select>
   </fieldset>
 </div>

JS

var accounts = [{"id":-1,"text":"","description":null}, {"id":25,"text":"J13002","description":null}, {"id":28,"text":"J13053","description":null}];

var LaborListModel = function(laborModels) {
  var self = this;

  //contains all labor models
  self.labordetails = ko.observableArray(laborModels);
  self.selectedAccount = ko.observable();

  //bindings
  ko.bindingHandlers.updateaccountdropdown = {
    init: function(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        ko.utils.domNodeDisposal.addDisposeCallback(element, function() {
            $(element).select2('destroy');
        });

        var allBindings = allBindingsAccessor(),
            select2 = ko.utils.unwrapObservable(allBindings.updateaccountdropdown);
        $(element).select2(select2);
    },
    update: function(element, valueAccessor, allBindingsAccessor, viewModel, bindingContext) {
        var allBindings = allBindingsAccessor();
        if ("value" in allBindings) {
            var val = ko.utils.unwrapObservable(valueAccessor());
            $(element).val(val.id).trigger('change');
        }
    }
  };
}

getAllLaborDetails().done(function(result) {
   loadAccounts().done(function(_accounts) {
     accounts = _accounts;
     for (var i = 0; i < result.length; i++) {
       //LaborModel
       var laborDetails = [];
       laborDetails.push(new LaborModel(
         result[i].labourDetailId,
         result[i].account,
         result[i].categoryModel,
         result[i].description,
         result[i].timeStamp,
         result[i].hour
       ));
     }
     var vm = new LaborListModel(laborDetails);
     ko.applyBindings(vm);
   });
})