React is able to render custom attributes as described at http://facebook.github.io/react/docs/jsx-gotchas.html:
If you want to use a custom attribut
I do not know about React, but in the general case you can pass custom attributes like this:
1) define inside an html-tag a new attribute with data- prefix
data-mydatafield = "asdasdasdaad"
2) get from javascript with
e.target.attributes.getNamedItem("data-mydatafield").value