Error when creating multiple PDFs in Google Apps Script - pdf

Question

I've created a function that saves a spreadsheet (sheet) as PDF to a specified folder. The function works great but when I run it in multiple times (I need to do it 20 times), I get an error after the 7th, 8th or 9th run. The error is 429. It doesn't give me a whole lot of info and I can't seem to find what the error is and how to correct. I've tried adding a Utilities.sleep(xxx) and it does work when I do a 5 second sleep (but not when it's less than 5 seconds)!
Here's my code (with Utilities.sleep):
/**
* Creates a PDF file
*
* 2019-12-17 Simon: Created
*
* #param {?} token ScriptApp.getOAuthToken();
* #param {?} spreadsheet Spreadsheet (SpreadsheetApp.getActiveSpreadsheet())
* #param {string} sheetName Name of the sheet to print
* #param {string} pdfName Name of the pdf file (excluding .pdf)
* #param {string} folder Folder to save in
* #param {string} portrait true=portrait, false=landscape
* #param {number} scale 1 = Normal 100% -- 2 = Fit to width -- 3 = Fit to height -- 4 = Fit to Page
* #param {number} margins In inches. Dot as decimal separator, e.g. '0.2'
* #param {string} range Optional. E.g. 'D4:AX74'
*/
function savePdf(spreadsheet, sheetName, pdfName, folder, portrait, scale, margins, range) {
var rangeUse = (range ? '&range=' + range : '');
var sheetId = spreadsheet.getSheetByName(sheetName).getSheetId();
var url_base = spreadsheetId.getUrl().replace(/edit$/,'');
var url_ext = 'export?'
+ '&gid=' + sheetId
+ rangeUse
+ '&format=pdf' // export format
+ '&size=a4' // A3/A4/A5/B4/B5/letter/tabloid/legal/statement/executive/folio
+ '&portrait=' + portrait // true = Potrait / false= Landscape
+ '&scale=' + scale // 1 = Normal 100% -- 2 = Fit to width -- 3 = Fit to height -- 4 = Fit to Page
+ '&top_margin=' + margins // all four margins must be set!
+ '&bottom_margin=' + margins // all four margins must be set!
+ '&left_margin=' + margins // all four margins must be set!
+ '&right_margin=' + margins // all four margins must be set!
+ '&gridlines=false' // true/false
+ '&printnotes=false' // true/false
+ '&pageorder=2' // 1 = Down, then over -- 2 = Over, then down
+ '&horizontal_alignment=CENTER' // LEFT/CENTER/RIGHT
+ '&vertical_alignment=MIDDLE' // TOP/MIDDLE/BOTTOM
+ '&printtitle=false' // print title --true/false
+ '&sheetnames=false' // print sheet names -- true/false
+ '&fzr=true' // repeat row headers (frozen rows) on each page -- true/false
+ '&fzc=true' // repeat column headers (frozen columns) on each page -- true/false
+ '&attachment=false' // true/false
var token = ScriptApp.getOAuthToken();
var url_options = {headers: {'Authorization': 'Bearer ' + token, 'muteHttpExceptions': true,}};
Utilities.sleep(5000);
var response = UrlFetchApp.fetch(url_base + url_ext, url_options);
var blob = response.getBlob().getAs('application/pdf').setName(pdfName + '.pdf');
folder.createFile(blob);
}

Answer 1

Changed the script to make a copy of the spreadsheet in the beginning and working on that copy – and trash it at the end.
Here's the final working script:
/**
* Creates a PDF file
*
* 2019-12-17 Simon: Created
*
* #param {?} spreadsheet Spreadsheet (SpreadsheetApp.getActiveSpreadsheet())
* #param {string} sheetName Name of the sheet to print
* #param {string} pdfName Name of the pdf file (excluding .pdf)
* #param {string} folder Folder to save in
* #param {string} portrait true=portrait, false=landscape
* #param {number} scale 1 = Normal 100% -- 2 = Fit to width -- 3 = Fit to height -- 4 = Fit to Page
* #param {number} margins In inches. Dot as decimal separator, e.g. '0.2'
* #param {string} range Optional. E.g. 'D4:AX74'
*/
function savePdf(spreadsheet, sheetName, pdfName, folder, portrait, scale, margins, range) {
var rangeUse = (range ? '&range=' + range : '');
var ssNew = spreadsheet.copy('temp');
var sheetId = spreadsheet.getSheetByName(sheetName).getSheetId();
var url_base = spreadsheet.getUrl().replace(/edit$/,'');
var url_ext = 'export?'
+ '&gid=' + sheetId
+ rangeUse
+ '&format=pdf' // export format
+ '&size=a4' // A3/A4/A5/B4/B5/letter/tabloid/legal/statement/executive/folio
+ '&portrait=' + portrait // true = Potrait / false= Landscape
+ '&scale=' + scale // 1 = Normal 100% -- 2 = Fit to width -- 3 = Fit to height -- 4 = Fit to Page
+ '&top_margin=' + margins // all four margins must be set!
+ '&bottom_margin=' + margins // all four margins must be set!
+ '&left_margin=' + margins // all four margins must be set!
+ '&right_margin=' + margins // all four margins must be set!
+ '&gridlines=false' // true/false
+ '&printnotes=false' // true/false
+ '&pageorder=2' // 1 = Down, then over -- 2 = Over, then down
+ '&horizontal_alignment=CENTER' // LEFT/CENTER/RIGHT
+ '&vertical_alignment=MIDDLE' // TOP/MIDDLE/BOTTOM
+ '&printtitle=false' // print title --true/false
+ '&sheetnames=false' // print sheet names -- true/false
+ '&fzr=true' // repeat row headers (frozen rows) on each page -- true/false
+ '&fzc=true' // repeat column headers (frozen columns) on each page -- true/false
+ '&attachment=false' // true/false
var token = ScriptApp.getOAuthToken();
var url_options = {headers: {'Authorization': 'Bearer ' + token, 'muteHttpExceptions': true,}};
var response = UrlFetchApp.fetch(url_base + url_ext, url_options);
var blob = response.getBlob().getAs('application/pdf').setName(pdfName + '.pdf');
folder.createFile(blob);
DriveApp.getFileById(ssNew.getId()).setTrashed(true);
}

Answer 2

I ran into this once and was able to fix it by removing the call to ScriptApp.getOAuthToken() out of the recursive portion of the function. I think the easiest way to do this in your case with minimal complication would be to use the CacheService.
replace the line var token = ScriptApp.getOAuthToken();
with:
var token;
if(CacheService.getScriptCache().get('token')!=null) {
token = CacheService.getScriptCache().get('token');
} else {
token = ScriptApp.getOAuthToken();
CacheService.getScriptCache().put('token',token,120);
}
This will store the token value in the CacheService instead of calling it recursively with your script loop. Hopefully this solves your issue as it did mine.
Edit:
After the above didn't fix your issue I looked back at what I had done and wrongly assumed that it was fetching the token that had caused my issue, but it was a rate limit on exporting from the Google Sheets API. Here's what I noticed ACTUALLY fixed MY issue at the time:
The rate limit (see my last paragraph for my thoughts on this) is per SHEET and not per user -- my recursive script was accessing two different sheets at the time so the natural delay in the function created just enough time delay for my script to run its course without problems.
Now to a fix for your drama:
After duplicating your problem I modified my parent function to create a copy of the main spreadsheet:
var mainsheetcopy = mainsheet.copy('Copy of main sheet')
and then switch between the two spreadsheets to send the call to the function to extract the PDF. I was able to iterate through the extraction of 20 pdfs with a sleep delay of only 750ms, and 18 iterations with no delay at all built in.
for(var i=0; i<20; i++) {
if(isEven(i)) {
sheetid = mainsheet.getId();
} else {
sheetid = mainsheetcopy.getId()}
for reference, the isEven function is below:
function isEven(n) {
return n % 2 == 0;
}
Then, at the end of the script I deleted the copy:
DriveApp.getFileById(mainsheetcopy.getId()).setTrashed(true);
If time is a factor, you could create a third copy of the main spreadsheet and through only the delay that the function takes naturally it would put you outside of the rate limit that they have on exporting the sheet as a PDF.
The actual rate limit is a bit elusive, but one sheet every 7.5-8 seconds seems to skirt this. I was able to iterate up to 5 PDF files exported per sheet with no rate limit 100% of the time and 6 occasionally.