How to check for NULL values?

[supetrmp]

What is the recommended way of testing for NULL values? For example I have created an Image type page input that is stored in a Data Item without setting an initial value (empty). I would like to test if the Image Data Item is empty at the start of the page. I am doing this in an Object by the way... Thanks!

[JustinBishop]

If your data stage has no initial value then you can simply use a decision stage with the expression [data]"""" Hope that helps. Justin

[supetrmp]

@Justin Bishop It works for text or number data types, but not for images... I still used it, but resorted to catch the exception that throws.

[PatrickChilders]

a month late, i realize, but you can have another data item on the page that is of the type Picture, but don't put anything in it. then substitue the """" in justin's example with that blank picture item