The SideErrorHandler, the default ErrorHandler for Fields reduces the field with when showing the error icon. This is a new feature in 3.0 which makes it easier to design your forms as the error icon does not extend past the field. This can be disabled if so desired. That being said, there was a bug in beta 1 with resizing the fields. This is now fixed in SVN. You can verify this change here:
Enter an invalid date into the birthday field and blur the field. You will now notice we show an error when parsing fails. Once you focus the field again, that error will be cleared. Does this make sense and work for you?
This change is in SVN and will go out next week in our beta 2 release. Thanks for the positive feedback on beta 1.
Yes, this is a nice feature to have when using the DateField widget within the FieldLabel widget when designing forms.
For charting controls I am using two DateFields standalone (without the FieldLabel widget) as part of an XTemplate (please see originally attached file).
So, if the overall width stays the same when there is an error or not, and room is made for the error icon so that it does not overlay something to the right, then that works for me.
If there will be a method to turn off this new behavior (meaning that the DateField width stays the same when there is an error or not, and the error icon overlays whatever may be to the right), then that works for me as well.