opinput expression function

Returns the name of the node connected to a given input.

See also: opinputpath, opninputs, opoutput, opoutputpath

index is the 0-based number of the input. For example, to get the name of the node connected to the first input, use opinput(".", 0), and for the second input, use opinput(".", 1).

point("../" + opinput(".", 0), $PT, "P", 0)