This document is a tutorial on how to interface Nasal scripts with FlightGear. It is not an introduction to the Nasal language itself. For that, see Andy's Nasal website at http://www.plausible.org/nasal. The information there is sparse, but you should have it ready for reference while reading this document.
<binding> tag.
The relevant command type is "nasal", and you place your Nasal code
inside of the <script> tag:
<binding>
<command>nasal</command>
<script>
print("Binding Invoked!");
</script>
</binding>
The code above invokes the print() function. This is
a simple extension function that simply prints out its arguments, in
order, to the FlightGear console as a single-line log entry. It is
useful for debugging, but little else.
Some command have SGPropertyNode arguments. This argument is
available as a props.Node object and is returned from the
built-in cmdarg() function. See below for full
documentation, but as an example the following "joystick axis" binding
will print the current axis value to the console:
<binding>
<command>nasal</command>
<script>print(cmdarg().getNode("value").getValue());</script>
</binding>
Note that the current imple