Hello,

A Date/Time Picker is bound to a nullable DateTime value. If the user clears the value with the keyboard, the component will show as invalid (with red border). Instead, the picker should treat null values as valid.

Here is a test page with a few different workarounds:

<TelerikButton OnClick="@( () => DateValue = null )">Clear Value</TelerikButton>
<TelerikButton OnClick="@( () => DateValue = DateTime.Now )">Set Value</TelerikButton>

DateValue.HasValue: @DateValue.HasValue

<p>Default behavior:</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px" />

<p>Red border will disappear after blur (CSS):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   Class="@( !DateValue.HasValue ? "valid-null" : "" )" />

<p>Red border will never appear (CSS):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   Class="valid-null" />

<p>Red border will disappear after blur (OnChange):</p>

<TelerikDatePicker @bind-Value="@DateValue"
                   Width="200px"
                   OnChange="@OnPickerChange" />


<style>
    .k-input.k-invalid.valid-null {
        border-color: rgba(0, 0, 0, 0.08);
    }
</style>

@code {
    private DateTime? DateValue { get; set; } = DateTime.Now;

    private async Task OnPickerChange(object newValue)
    {
        DateTime? newDate = (DateTime?)newValue;

        if (!newDate.HasValue)
        {
            DateValue = DateTime.Now;
            await Task.Delay(1);
            DateValue = null;
        }
    }
}

Is there any way to display the DateTimePicker and for the time picker to display time intervals of less than one second?  For example every 15 minutes?

Select a time:

15:00

15:15

15:30

15:45

etc?

With Blazor server, clicking the NOW button (obviously) sets the time to the time on the server since that's where the code is running. Is there a way to trap the NOW button click or somehow give it an offset or define the value that NOW means so NOW will mean the time that the user is sitting in?

---

ADMIN EDIT

One way this could land could be through templates for the header areas of the calendars - that would let you put your own NOW button there so you can handle its click and change the value as desired. So, you may want to follow and/or Vote for this approach here: https://feedback.telerik.com/blazor/1468855-header-template-for-the-calendars.

A workaround for the time being could be hiding the Now button with some CSS:

<style>
    .no-now-button .k-time-now {
        display: none;
    }
</style>

Selected time: @selectedTime
<br />

<TelerikDateTimePicker PopupClass="no-now-button"
                       Min="@Min" Max="@Max" @bind-Value="@selectedTime"
                       Format="dd MMM yyyy HH:mm:ss" Width="250px"></TelerikDateTimePicker>

@code {
    private DateTime? selectedTime = DateTime.Now;
    public DateTime Min = new DateTime(1990, 1, 1, 8, 15, 0);
    public DateTime Max = new DateTime(2025, 1, 1, 19, 30, 45);
}

---

Add "OnOpen" event that fires when the DateTimePicker  button is clicked but before the DateTimePicker  dropdown is shown

=============

ADMIN EDIT

=============

You can currently achieve the desired behavior by wrapping the DateTimePicker in a container (for example span), add a handler on the on-click event of the span to catch the click event and perform the desired actions in that handler.

<span class="datetimepicker-span" @onclick="@OnOpenHandler">
    <TelerikDateTimePicker Class="my-date-time-picker" Value="@selectedTime"
                           Format="dd MMM yyyy HH:mm:ss" Width="250px"></TelerikDateTimePicker>
</span>

@code {
    public DateTime? selectedTime { get; set; }

    public bool isOpened { get; set; } = false;

    public void  OnOpenHandler()
    {
        isOpened = !isOpened;

        if (isOpened)
        {
            Console.WriteLine("DateTimePicker was opened.");
        }
        else
        {
            Console.WriteLine("DateTimePicker was closed.");
        }
    }
}

If you enter a format with a 24 hour time( Format="dd MMM yyyy HH:mm:ss")  for the Timepicker

If you enter the same format for the DateTimePicker the TimePicker in the DateTimePicker looks like this:

It seems like this is a bug as the only way I can change the DateTimePicker time UI is to alter my language/culture whereas the TimePicker displays correctly based on my format. 

Hi.

When entering an invalid date in a DateTimePicker, the component will automatically revert the entered value back to its previous valid value.

I didn't expect this because the user may type in an invalid date, and continue to the next input control within the form, and not notice the error that was briefly displayed.

The issue can be reproduced in the DateTimePicker Demo here: https://demos.telerik.com/blazor-ui/datetimepicker/validation

Steps to reproduce:

1. Click in the day part of the date.

2. Enter 13

3. Enter 2100

4. Press the Tab key

5. Notice the date is automatically reverted (back) to 10/13/2019.

I expected the date to be set to 10/13/2100 with the input validation errors visible to the user after pressing the Tab key in step 4.

I've categorized this issue as a bug because otherwise, the form can be submitted with a value that the user did not enter.

If this behavior cannot be changed from being the default behavior, then there should be an option to prevent this behavior from happening.

Thank you.

Hey Telerik team,

We encountered issue with DateTime picker which I was able to reproduce in your Documentation preview.

If you hover over the date time dropdown, but really slowly it bugs out and the view becomes unusable like this:

As you can see, the dropdown is messed up and it seems like the hover over the border is trying to trigger some action to change from date to time pick automatically

Jakub

I'd like to have the ability to disable dates and times.

I want to set the initially focused time/date for the DateTimePicker before opening the picker to improve the user experience. When opening the DateTimePicker with a null value the preselected date is the current day and the time is always 00:00/12:00AM.

I do not want to set value for the component but rather alter the time/date that will be initially focused when opening the popup.

===

ADMIN EDIT

===

The request also applies to the rest of the pickers - DatePicker, DateRangePicker and TimePicker.

If you are zooming a page containing a DateTimePicker with "AdaptiveMode" set to "AdaptiveMode.Auto", the application crashes occasionally with the error:

Microsoft.JSInterop.JSException: Cannot read properties of null (reading 'addEventListener')
TypeError: Cannot read properties of null (reading 'addEventListener')

The more adaptive DateTimePicker instances the page contains, the more likely the error is to occur.

The input in the DateTimePicker is valid when:

- the DateTimePicker value is bound to nullable DateTime and

- the user clears the input

In such cases, the input field shouldn't get a red border.

Here is a REPL example to reproduce the issue:

1. Select a date.
2. Clear the date. The input gets a red border.

===ADMIN EDIT===

A possible workaround is to change the border color with CSS. Here is a REPL example.

DateTimePicker loses focus when the NOW button is clicked. 

To reproduce the problem open the following demo:

https://demos.telerik.com/blazor-ui/datetimepicker/overview

Try clicking a few times on the NOW button. The focus is occasionally lost. 

https://www.screencast.com/t/BPEXTy43

I want the user to only be able to select times between, for example, 11AM and 1PM. Setting Min and Max does not limit that, I can select any time:

Based on the example https://demos.telerik.com/blazor-ui/datetimepicker/overview, on Cancel or Set, the Input gets focused. On the mobile, it causes the keyboard to appear as well, which is not an intuitive behaviour.

Is it possible for this behaviour to be removed?

---

ADMIN EDIT

This behavior is OS specific, in our tests iOS does not exhibit it. It is generally up to the OS to show the soft keyboard and the web app should not be able to alter that.

Also, generally speaking from an accessibility point of view, popups must have a default focus (we do that), and when they close, they must return the user to the flow of the application in the place where they took it from. In this case, that's an interaction with the picker component.

Nevertheless, if the focus went to the button rather than the input, it is highly likely that the behavior would be resolved. The only downside would be that Android users will need a second action to get the focus back in the input.

---

Hi,

I have a REPL showing the issue.

I am using DataAnnotation where possible in my application and I was expecting the DisplayFormat attribute to be applied in the DateTimePicker like it is for DatePicker but as shown in the REPL link below it's not. I will use a workaround of applying the Format attribute everywhere but I would appreciate this being changed.

https://blazorrepl.telerik.com/GdkpcclE28sZ9VZH54

I've determined that the TelerikDateTimePicker does not work properly on mobile devices when using AdaptiveMode.Auto. Attached are videos of the component's behaviour in both modes (None, and Auto).

Immediately after interacting with the fullscreen popup of the datepicker, I see this error in the console:

RAW:
telerik-blazor.js:50 Uncaught TypeError: r.isParent is not a function
    at p.isChild (telerik-blazor.js:50:1362352)
    at f.closePopup (telerik-blazor.js:50:1398427)
    at HTMLHtmlElement.onMouseDown (telerik-blazor.js:50:1397246)

Code:

@using Telerik.Blazor.Components
@using Telerik.Blazor

<TelerikFloatingLabel Text="Date & Time">
    <TelerikDateTimePicker Id="date-picker" @bind-Value="MyFormModel.Date" Max="@DateTime.Now.AddDays(1)"
                           Format="@DATE_FORMAT" AdaptiveMode="AdaptiveMode.Auto"
                           FillMode="@Telerik.Blazor.ThemeConstants.DateTimePicker.FillMode.Flat" />
</TelerikFloatingLabel>

@code {
    private FormModel MyFormModel { get; set; } = new FormModel();
    private const string DATE_FORMAT = "MM/dd/yyyy HH:mm";

    private class FormModel
    {
        public DateTime Date { get; set; }
    }
}

Notes:
- If we remove all of the parent components wrapping the DatePicker, it seems to function properly, but the errors remain in the console. This isn't a solution, however.