How to convert Google spreadsheet's worksheet string id to integer index (GID)?

Question

To export google spreadsheet\'s single worksheet to CSV, integer worksheet index(GID) is required to be passed.

https://spreadsheets.google.com/feeds

Answer 1

This code works with the new Google Sheets.

// Conversion of Worksheet Ids to GIDs and vice versa
// od4 > 2
function wid_to_gid(wid) {
    var widval = wid.length > 3 ? wid.substring(1) : wid;
    var xorval = wid.length > 3 ? 474 : 31578;
    return parseInt(String(widval), 36) ^ xorval;
}
// 2 > od4
function gid_to_wid(gid) {
    var xorval = gid > 31578 ? 474 : 31578;
    var letter = gid > 31578 ? 'o' : '';
    return letter + parseInt((gid ^ xorval)).toString(36);
}