Google script save / update file - google-apps-script

Question

I am again creating a simple script to save a daily menu cart. Aim is, that the file (PDF) can be shared with a static link. Base for the PDF is a Google spreadsheet.
Currently I have the following code:
// Add new menu to sheet
function onOpen() {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var entries = [
{name: "Speichern", functionName: "savepdf"},
];
spreadsheet.addMenu("Als PDF speichern", entries);
};
// Add function to save sheet as PDF
function savepdf () {
// Get spreadsheet file
var fileid = 'FILEIDGOESHERE';
// Create date for file name
var ss = SpreadsheetApp.openById(fileid);
var name = ss.getName();
var sheet = ss.getSheetByName('Tageskarte');
var range = sheet.getRange(12,1);
var d = range.getValue();
var curr_date = d.getDate();
var curr_month = d.getMonth() + 1;
var curr_year = d.getFullYear();
var theDate = curr_year + "-" + curr_month + "-" + curr_date + "-";
var namearchive = "Tageskarte-"+ theDate +".pdf";
var name = "Tageskarte-Allweglehen.pdf";
// Choose folder where PDFs are saved
var foldersave=DriveApp.getFolderById('FOLDERIDGOESHERE');
var foldersavearchive=DriveApp.getFolderById('FOLDERIDGOESHERE');
// OAuth
var request = {
"method": "GET",
"headers":{"Authorization": "Bearer "+ScriptApp.getOAuthToken()},
"muteHttpExceptions": true
};
// Create PDF + update current file
var fetch='https://docs.google.com/spreadsheets/d/'+fileid+'/export?format=pdf&size=A4&portrait=true&gridlines=false'
var pdf = UrlFetchApp.fetch(fetch, request);
pdf = pdf.getBlob().getAs('application/pdf').setName(name);
var file = foldersave.createFile(pdf);
// Create PDF for archive and save
var pdfarchive = UrlFetchApp.fetch(fetch, request);
pdfarchive = pdfarchive.getBlob().setName(namearchive);
var file = foldersavearchive.createFile(pdfarchive);
}
/*
fmcmd=12
size=legal/A4
fzr=true/false
portrait=false/true
fitw=true/false
gid=0/1/2
gridlines=false/true
printtitle=false/true
sheetnames=false/true
pagenum=UNDEFINED
attachment=false/true
*/
My problem is the point "Create PDF + update current file. The code is saving a new file with the same name, but than I have of course a new static share link of the menu.
I think I have to use something with the "getblob" function to update the current file.
Would be very good, if anybody would have an idea.
Many thanks.

Answer 1

I was able to find a working solution with Drive.Files.update
// Create PDF + update current file
var fetch='https://docs.google.com/spreadsheets/d/'+fileid+'/export?format=pdf&size=A4&portrait=true&gridlines=false'
var pdf = UrlFetchApp.fetch(fetch, request);
pdf = pdf.getBlob().getAs('application/pdf').setName(name);
var deleteexisting = foldersave.getFilesByName(name);
if (deleteexisting.hasNext() === false) {
// if no file is found then create it
foldersave.createFile(pdf);
} else {
while (deleteexisting.hasNext()) {
var updatedPDF = deleteexisting.next();
Drive.Files.update({mimeType: 'application/pdf'}, updatedPDF.getId(), pdf);
}
}