  Behavior Trees (BTs) provide a lean set of control flow elements that are
easily composable in a modular tree structure. They are well established for
modeling the high-level behavior of non-player characters in computer games and
recently gained popularity in other areas such as industrial automation. While
BTs nicely express control, data handling aspects so far must be provided
separately, e. g. in the form of blackboards. This may hamper reusability and
can be a source of nondeterminism. We here present a dataflow extension to BTs
that explicitly models data relations and communication. We provide a combined
textual/graphical approach in line with modern, productivity-enhancing
pragmatics-aware modeling techniques. We realized and validated that approach
in the recently introduced polyglot coordination language Lingua Franca (LF).
