How to show Customize message with ZK Constraint?

Here is the code you can follow

Here two condition added

Textbox should not be empty .

Textbox not allow any space trailing and leading spaces.

ZK Upload a image or Image binding In MVVM Architecture

The ZUL file code for this will be
and in you View Model class you have to use this code snap..
I have used image tab only for showing a uploading image if you want to upload the image only you do not need to use the image tag in the page.
Note:- I have removed unwanted line of code so may be code will be not compile but this is a way to work with image.You can made changes in code according to your requirements.
The detail method of showInfo()