[Date Picker] The date picker doesn't return the correct value when submitting the form with 'onChange' callback

[ko2in]

Bug Report

I've a form with date picker and I setup to submit the form as soon as the date is picked and send the form data to the server. But, the form always sends the previous selected date.

Testcase

You can test in this fiddle (http://jsfiddle.net/m7wn3xus/3/). The date picker has onChange callback, which triggers the submit event of the form. You can see the serialized array of form data below. The form always send the previous value from the date picker.

Current Workaround Solution

I've to update the input field value with the selected date before triggering the submit event. You can test in this fiddle (http://jsfiddle.net/yka8fpsr/1/). The form will be sent the correct date to the server.

In my real world project, I'm implementing the search filters with several date fields and send to the server via Ajax request when the fields have changed the values.

The browser native onChange event has no effect on the date picker field. Looks like the date picker module unbind the default events. Try this fiddle (http://jsfiddle.net/54gsqa27/). The two text fields listen the change event, but the date picker field doesn't.

So, the only way to trigger the change event is using onChange callback from the date picker API, which causes the issue.

Version

2.7.1

[ColinFrick]

You are right, this differs to other modules where the onChange callback is called after the input is updated.

Splitting the onChange in beforeChange and onChange which is called after the value is set makes sense, but means a breaking change. This is similar to the checkbox module:
beforeChecked: Callback before a checkbox is checked. Can cancel change by returning false
onChecked: Callback after a checkbox is checked.

In the meantime you can delay submitting the form with setTimeout inside onChange: http://jsfiddle.net/fj3yxzh9/

[ko2in]

@ColinFrick Thanks. That would do the trick at the moment 👍. Looking forward to the next release and the actual fix.

[prudho]

Fixed by #982.