We have the following problem. For some reason when we use HTML input with type "number" on a real device (not a web browser), deleting the minus sign results with an input element that shows the user a number while the value of the input element is empty string.
Kendo validator is attached to this input element, but we are not certain the problem has anything to do with the validator. We think it might be because there is shadow-content associated with the element on mobile devices.
The attached screens demonstrates the issue: in number-input-before-delete-minus-sign-GOOD.PNG you can see the input value right after we entered it and the minus sign was added correctly by code (*-1); in number-input-after-delete-minus-sign-BAD.PNG you can see that after manually removing the minus sign from the input field by the user, testing the input value shows empty result. The screens were taken from iPhone 5s running iOS 8.4.1 but the same problem occurs in other devices (other OSs) as well.
We created the following Dojo with which you can experience the problem: http://dojo.telerik.com/opiNA/5
Dojo instructions: Enter a positive number (e.g. 3); Click the test value button - you will see the element value is -3 as expected, because the code takes the original value and multiply it by -1 . Now Delete the minus sign. You would expect the test value, which simply shows the element value, will show you 3. But it will show you nothing. For some reason the value became an empty string even though we can still see the value in the HTML element.
Any idea how we can handle this issue?