Trying to retrieve Google File ID for an image in google sheets

Question

I have an Appsheet app, for which I am trying to get the Google File ID of an image that I have taken through the app.

When the image is taken in the app, it is stored in the associated Sheets file by its name, which looks like this:

Expenses_Images/1.Receipt Image.111508.jpg

I would like to use an Appscript to find the relevant image in Google drive and show the file ID as a result in the following column. The sheet would look something like this:

Expense                   Image                     File ID

Expenses_Images/1.Receipt Image.111508.jpg......... XXXXXXXXXX

Where XXXXXX is the file ID i'm trying to retrieve and Expense, Image and File ID are the column headers. I would like the appscript to automatically find the File ID whenever a new row is added to the spreadsheet.

I have the following appscript, but I'm not sure it is going to achieve exactly what I want.

function list_all_files_inside_one_folder_without_subfolders(){
    var sh = SpreadsheetApp.getActiveSheet();
    var folder = DriveApp.getFolderById(‘ChangeHereToYourFileFolderId’);
    var list = ;
    list.push([‘Name’,‘ID’,‘Size’]);

    var files = folder.getFiles();
    while (files.hasNext()){
        file = files.next();
        var row = row.push(file.getName(),file.getId(),file.getSize())
        list.push(row);
    }
    sh.getRange(1,1,list.length,list[0].length).setValues(list);
}

Answer 1

To retrieve a fileID from the name of the file ...

function getFileId(fileName) {
  var files = DriveApp.getFilesByName(fileName);
  while (files.hasNext()) {
    var file = files.next();
    return (file.getId())
  }
}

You can call this function this ay for instance

function test(){
  var sh=SpreadsheetApp.getActiveSheet()
  for (var i =1;i<=sh.getLastRow();i++){
    id = getFileId(sh.getRange(i,1).getValue())
    try {sh.getRange(i,2).setValue(id)}
    catch(e){sh.getRange(i,2).setValue(e)}
  }
}