title: Suggestions for Making a Flowchart Library that uses JSON as Markup
body: <p>So recently at work I have been tasked with creating a Flowchart library.  I would just like to get some general suggestions on how I should approach this.  We use mongodb for persistence, and Tornado Web Server as a backend.  Basically what I need is to create a library in javascript that has a means of importing JSON in order to display a flow chart.  This flowchart will definitely not be trivial, and I will require the ability to model loops, conditions, etc.  Basically everything that a standard UML activity diagram would be required to model.  I plan on using Raphael to draw the vectors connecting each node on screen.  I guess my biggest question is, how would I model loops and conditions in JSON?  Are there pre-existing open-source libraries that do what I am suggesting to use as reference?</p>