Script only works when uploading a single file - google-apps-script

Question

When an employee submits the google form, this script renames the file they have uploaded based off of information said employee fills out in the form. (At the moment it is pulling their Name, Job ID, and Address of the current job location, the file is always pictures of what they completed on the jobsite.)
However the script only pulls this information if a single file/picture is uploaded the form instead of all files.
What modification would allow this to rename all uploaded files in the form.
while (files.hasNext()) {
for (var i = 0; i < formResponses.length; i++) {
var formResponse = formResponses[i];
var itemResponses = formResponse.getItemResponses();
var itemResponseFname = itemResponses[0];
var itemResponseLname = itemResponses[10];
var itemResponseID = itemResponses[11];
var itemResponsePhoto = itemResponses[13];
var photoID = itemResponsePhoto.getResponse();
var newName = itemResponseFname.getResponse() + " " + itemResponseLname.getResponse() + " - " + itemResponseID.getResponse();
var url = baseString + photoID + endString;
var urlCheck = file.getUrl();
if ( url == urlCheck) {
var modName = newName + ".jpg";
file.setName(modName);

Answer 1

The easiest way of doing such thing is the following:
Install a submit trigger
Get the list of IDs of submitted files
Change its name to whatever you like
In practice this will look something like this:
function submit(e) {
const itemResponses = e.response.getItemResponses()
// Read values
const fname = itemResponses[0].getResponse()
const lname = itemResponses[10].getResponse()
const uid = itemResponses[11].getResponse()
const imageIds = itemResponses[13].getResponse()
// Iterate images
for (let imgId of imageIds){
const image = DriveApp.getFileById(imgId)
// Create new filename (preserves extension)
const filename = `${fname} ${lname} - ${uid}${getExtension(image)}`
// Set file name
image.setName(filename)
}
}
/**
* Returns the extension of a file
*
* For example: A file with name 'example.json' will return '.json'.
*
* #param file {DriveApp.File} File to extract the extension from
* #returns {string} The extension with the dot.
*/
function getExtension(file) {
// Gets the last dot and the characters that follow
const r = /(\.\w+)$/.exec(file.getName())
// If it has no extension return an empty string, otherwise return the captured group
return r === null ? '' : r[1]
}
Obviously you need to add all your other code that you seem to have and install the trigger if you haven't, already.