问题
This is the datepicker binding i'm using (im sorry but i forgot where i took it so i can't give the author proper credit. I will edit if i remember.)
ko.bindingHandlers.datepicker = {
init: function(element, valueAccessor, allBindingsAccessor) {
//initialize datepicker with some optional options
var options = allBindingsAccessor().datepickerOptions || {};
$(element).datepicker(options);
//when a user changes the date, update the view model
ko.utils.registerEventHandler(element, "changeDate", function(event) {
var value = valueAccessor();
if (ko.isObservable(value)) {
value(event.date);
}
});
},
update: function(element, valueAccessor) {
var widget = $(element).data("datepicker");
//when the view model is updated, update the widget
if (widget) {
widget.date = ko.utils.unwrapObservable(valueAccessor());
if (widget.date) {
widget.setValue();
}
}
}
};
function Model() {
this.date = ko.observable();
}
function VM() {
this.model = new Model();
this.save = function(model) {
$.post(someEndpoint, {model: model});
}
}
<input type='text' data-bind='datepicker: model().date,
datepickerOptions: { format:"dd/mm/yyyy"}' />
This datepicker binding, and Bootstrap datepicker in general, deals with Date objects. So my observable will contain Dates.
When i post data i see in console that it's posted with natural JS toString() format, which can vary according to your locale settings. For me, its
Mon Dec 02 2013 01:00:00 GMT+0100 (ora solare Europa occidentale)
When i receive this value server-side, i can't handle it because of this weird format.
I could of course rewrite my model date attribute before posting, like so
this.save = function(model) {
model.date(model.date().format('YYYY-MM-DD'));
$.post(someEndpoint, {model: model});
}
but this is not a general purpose solution, furthermore when model.date is updated to string representation, datepicker triggers an error since it's expecting Date.
How would you deal with this?
回答1:
For Bootstrap 3.0 and higher, these work for me:
Date Only For displaying the date, I use this bindingHandler:
window.ko.bindingHandlers.datetext = {
init: function (element, valueAccessor, allBindingsAccessor) {
// Provide a custom text value
var value = valueAccessor(), allBindings = allBindingsAccessor();
var dateFormat = allBindingsAccessor.dateFormat || "M/D/YYYY";
var strDate = window.ko.utils.unwrapObservable(value);
if (strDate) {
if (moment(strDate).year() > 1970) {
var date = moment(strDate).format(dateFormat);
$(element).text(date);
}
else {
$(element).text("-");
}
}
},
update: function (element, valueAccessor, allBindingsAccessor) {
// Provide a custom text value
var value = valueAccessor(), allBindings = allBindingsAccessor();
var dateFormat = allBindingsAccessor.dateFormat || "M/D/YYYY";
var strDate = window.ko.utils.unwrapObservable(value);
if (strDate) {
if (moment(strDate).year() > 1970) {
var date = moment(strDate).format(dateFormat);
$(element).text(date);
}
else {
$(element).text("-");
}
}
}
};
HTML
<!-- Display the date -->
<span data-bind="datetext: StartingDate"></span>
<!-- Set the date -->
<div class="input-group date">
<input type="text" class="form-control" data-provide="datepicker" data-bind="value: StartingDate"/>
<span class="input-group-addon">
<span class="glyphicon glyphicon-calendar"></span>
</span>
</div>
You'll need Moment.js. The datepicker used for this is located here
I'm using a C# backend, and posting to an MVC Controller or Web API controller poses no issues with DateTime variables. I.e:
this.save = function(model) {
$.post(someEndpoint, {model: ko.toJSON(model)});
}
Date and Time For displaying, I use this bindingHandler:
window.ko.bindingHandlers.datetimetext = {
init: function(element, valueAccessor, allBindingsAccessor) {
// Provide a custom text value
var value = valueAccessor(), allBindings = allBindingsAccessor();
var dateFormat = allBindingsAccessor.dateFormat || "M/D/YYYY h:mm a";
var strDate = window.ko.utils.unwrapObservable(value);
if (strDate) {
if (moment(strDate).year() > 1970) {
var date = moment(strDate).format(dateFormat);
$(element).text(date);
} else {
$(element).text("-");
}
}
},
update: function(element, valueAccessor, allBindingsAccessor) {
// Provide a custom text value
var value = valueAccessor(), allBindings = allBindingsAccessor();
var dateFormat = allBindingsAccessor.dateFormat || "M/D/YYYY h:mm a";
var strDate = window.ko.utils.unwrapObservable(value);
if (strDate) {
if (moment(strDate).year() > 1970) {
var date = moment(strDate).format(dateFormat);
$(element).text(date);
} else {
$(element).text("-");
}
}
}
};
For setting the datetime, I use this handler:
window.ko.bindingHandlers.datetimepicker = {
init: function(element, valueAccessor, allBindingsAccessor) {
$(element).parent().datetimepicker();
window.ko.utils.registerEventHandler($(element).parent(), "change.dp", function (event) {
var value = valueAccessor();
if (window.ko.isObservable(value)) {
var thedate = $(element).parent().data("DateTimePicker").getDate();
value(moment(thedate).toDate());
}
});
},
update: function(element, valueAccessor) {
var widget = $(element).parent().data("DateTimePicker");
//when the view model is updated, update the widget
var thedate = new Date(parseInt(window.ko.utils.unwrapObservable(valueAccessor()).toString().substr(6)));
widget.setDate(thedate);
}
};
HTML
<!-- Display the date -->
<span data-bind="datetimetext: FromDate"></span>
<!-- Set the date -->
<a data-bind="attr:{id: Id}" class="input-group date">
<input type="text" class="form-control" data-bind="datetimepicker: FromDate" />
<span class="input-group-addon">
<span class="glyphicon glyphicon-calendar"></span>
</span>
</a>
My server side method looks something like this:
[HttpPost]
public async Task<ActionResult> Update(MyViewModel myModel)
{
if (myModel.FromDate == new DateTime(0001, 01, 01))
{
if (!string.IsNullOrEmpty(myModel.sFrom))
{
myModel.sFrom = myModel.sFrom.Replace("/Date(", "").Replace(")", "").Replace("/", "").Trim();
var ticks = Convert.ToInt64(myModel.sFrom);
myModel.FromDate = new DateTime(1970, 1, 1).AddTicks(ticks * 10000).AddHours(-6);
}
}
var item = Mapper.Map<MyClass>(myModel);
await Task.Run(() => _myService.Save(item));
return Json(myModel);
}
With a model similar to this:
public class MyViewModel
{
public Guid Id { get; set; }
public DateTime FromDate { get; set; }
public string sFrom { get; set; }
}
The string version of the date (sFrom), is generated in my Javascript before I post to the server:
function saveModel(model) {
model.sFrom(model.FromDate().toString());
$.post(someendpoint, { model: ko.toJSON(model) }, function(data) {
ko.mapping.fromJS(data, {}, model);
});
}
Again, this uses Moment.js and this version of the datetimepicker is here
来源：https://stackoverflow.com/questions/20340196/knockoutjs-dealing-with-bootstrap-datepickers-and-date-formats