Get "last non-empty value" into trigger

[cbichis]

Hi,

In some situations I have items having empty values (in my case empty string). I am wondering how I can get into a trigger the last non-empty value of an item?

[Heilig]

You can use the latest value, next to last or two days ago received value (refer to function "last()"). But you will not be able put validation logic "if value was empty..." in trigger expression.
I do not know of your task, but perhaps function "nodata()" can helps...