I’ve also been looking for a way to get the key from a name. The best solution I’ve come up with is adding a function which does a switch/case on the field name and applies a filter to return the key. However, it does require that you manually code a case/return/break for each field (probably not practical if you’ve got more than a few dozen fields).
Code here: https://gist.github.com/wells5609/5971010
