Clearing a DropDown value

[Jason]

I've noticed what I think is a bug with the dropdown. If you bind a dropdown to a value (controlled in component state), you can have the value be undefined to start, and you get a dropdown with no selection. However, if you then manually select one of the entries, and programmatically set the value back to undefined, it does NOT clear the selection, even though the value (correctly) is undefined.

Is there some trick to this? For comparison, I used a vanilla textbox and the value does correctly clear, so I am pretty sure this is a Kendo issue.

[Jason]

FWIW, I found an old post relating to the jQuery framework suggesting the the ComboBox be used for this case, as opposed to the DropDown (that is, that this is known/"expected" behavior for the DropDown). I tried changing the controls to ComboBoxes, and still see the same result (setting the bound value to unknown or null does not actually update the displayed value).

The only workaround we've found is to have a dummy "<None>" entry in the list and "clearing" it back to that value. This is probably "good enough", but it seems like the control should be able to handle it natively (it DOES behave as desired when the value is initially undefined, but does not if the value gets set BACK to undefined).

[Stefan]

Hello, Jason,

This can be done setting the value to null instead of undefined.

Please check the following forum post this an example:

https://www.telerik.com/forums/how-to-clear-selected-item-from-dropdown

Regards,
Stefan
Progress Telerik

[Jason]

Thanks, Stefan! My coworker had said it didn't work with either undefined or null, and I only verified it myself with undefined. Not sure what he was doing that it didn't work with null, but I was able to see it work.