Calling a microflow with arguments

What I want to do is call a microflow which takes one string as argument (called chart). After reading the Calling microflow from widget-thread I couldn't find an answer. I also checked the documentation for mx.processor.get and mx.procressor.action but no luck. Is it possible to call microflows with primitive as argument? How is a primitive return handled?
1 answers

No, at the moment you can't call a microflow with primitive parameters through the client/server API, only locally (i.e. from another microflow) This is a long-standing issue that we'd love to change ourselves but never get around doing so please do file a feature request ;)

I don't know how the return value is handled (not a client dev myself) but it should be easy to check with firebug right?