I\'m playing around with Hstore for the first time in a rails4 app, and I am using javascript in a form to build out dynamic form fields for the hstore column (:schema)
I think Rails must have simplified this in recent versions (current as of 5.2.3 at least)... and much cleaner/easier:
params.require(:parent).permit(:name, :whatever, data: {})
This will allow and store any/all attributes of data into an hstore field. An example of POSTing or PUTing a data nested attribute via HTML: