I'm trying to write sort of a proxy to be able to query a Google Spreadsheet with Google Chart API without giving rights directly to the spreadsheet to people accessing the visualization.
In order to do that, I want to replace the calls like
var query = new google.visualization.Query('http://spreadsheets.google.com/tq?key=THE_KEY');
query.send(handleQueryResponse);
by calls of my Apps Script proxy (with JSONP).
I wrote the proxy as following : (I'll add later an option to encapsulate the result in a function - JSONP)
function doGet(e) {
return ContentService
.createTextOutput(
UrlFetchApp
.fetch("http://spreadsheets.google.com/tq?tq="+e.parameter.q+"&key="+e.parameter.key))
.setMimeType(ContentService.MimeType.JSON);
}
When trying to get a response, I obtain this error : google.visualization.Query.setResponse({"version":"0.6","status":"error","errors":[{"reason":"user_not_authenticated","message":"User not signed in","detailed_message":"\u003ca target=\u0022_blank\u0022 href=\u0022https://spreadsheets.google.com/spreadsheet/\u0022\u003eSign in\u003c/a\u003e"}]});
like if the user was not authenticated. I think it's weird because my script is deployed as a web app to be executed by my user, who has the rights on the spreadsheet. I guess we must use some OAuth, but I don't know how to authenticate the query that way.
So my question is : How to authenticate a query with Apps Script to access data with the access rights I defined when deploying as web app ?
