Recently I came across this note in a senior developer’s code review of a colleague’s work: “Slightly revised the user function to work correctly when languages other than English are used.” This was a surprising comment–the code is the code and it shouldn’t make a difference what language the developer or the end user speaks! A user function is simply an expression that may accept input parameters and returns a result.

Altova MobileTogether supports user functions in a cross-platform mobile development framework that combines drag-and-drop UI design and standardized functional programming for data selection and processing. Several MobileTogether demo applications are highly dependent on user functions and the MobileTogether Designer includes features that greatly assist creating and validating user functions.

Let’s take a look at user functions in mobile apps by examining one of these demo apps.