Thank you for sharing the links. Is there a pure JavaScript library that helps with reading and writing data from/to Google private spreadsheet? From the links above, I think node-google-speadsheet repo comes closest to what I'd like to achieve, but it uses node, which I'm not very familiar with.
・SQL into Sheets - http://pastebin.com/ACwqc5um
・LibreOffice Calc server - https://github.com/robsco-git/spreadsheet_server
・Sheets API (JS) - http://chriszarate.github.io/sheetrock/ | https://github.com/theoephraim/node-google-spreadsheet
・Grunt / Jekyll - https://github.com/stpe/grunt-gss-to-json
・simple read-only (JS) - https://github.com/franciscop/drive-db | https://github.com/digplan/gsheet-web
・auth proxy (Golang) - https://github.com/VLO-GDA/server-app