The usual way to access files and folders on Drive from Apps Script is via their ID, yet on other platforms we’re more used to using file and folder paths. This can be a bit random on Drive because

• files can have multiple parent folders
• more than 1 file with the same name can exist in the same folder

However, most of us don’t really do that so I’m still preferring to try to work with file and folder paths on Drive.

Another issue is that the file and folder iterators in DriveApp are not real V8 Iterators, so you can’t do things like for (x of files) or Array.from(files). I don’t like that either.

So this is a small library (bmFolderFun) to help fix all that.

Apps Script Initialization

There’s actually a class in the library, but you can’t expose a class from a library in Apps Script for some reason, so you can get a new instance of the class like this. Note that you pass your DriveApp to it. This is because all my libraries nowadays are, by design, dependency free. You’ll need to leave the comment in below to provoke a DriveApp authorization dialog if you’re not using DriveApp elsewhere in your app.

  // force a permission dialog with this comment 
  // DriveApp.getRootFolder()
  const ff =  bmFolderFun.paths(DriveApp)

Getting a folder by path

This will return a Drive Folder object (or null) for the folder matching the path

const folder =  ff.folderFromPath("/images/dump")

Getting a path from a folder

You may need to go the other way – this will generate a full path string from a given folder

const path = ff.pathFromFolder (folder)

Get files from a path

This will return all the files that match a path including a filename. There may be more than one with exactly the same name in the same folder, which is why it will return a file iterator – it’s annoying, but there it is.

const files =ff.getFiles("/somepath/somefile.txt")

Get a single file from a path

This returns the Drive File object that is returned first from a drive files iterator and is most common if you are not worried that there may be multiple files with the same name

const file =ff.getFile("/somepath/somefile.txt")

Iterators

Now we can start to use V8 iterators, by converting a Drive files or folders iterator into proper V8 iterators.

Get a v8 iterator from a files or folders iterator

Although these examples are all about Drive – any iterator with a hasNext()  and a next() will be converted with this function.

const iterator = ff.getIterator (driveIterator) 

Get a v8 iterator for all the files in a folder from a path

Finally, the most useful one – you can use this iterator to get all the file objects in a folder path string

const iterator = ff.iteratorFromFolderPath('/some/folder/path)

Example usage

Files in a folder iteration

Let’s say you want to iterate through all the files in a folder path

const files = ff.iteratorFromFolderPath("/some/folder/path/")
for (file of files) {
  console.log(file.getName())
}

Array from files in a folder path

Or map an array from all the files in a folder path

const names = Array.from(ff.iteratorFromFolderPath ("/some/folder/path/")).map (file=>file.getName())

Array from a folder object

or if you already have a folder object

const names = Array.from(ff.iterator(folder.getFiles())).map(file=>file.getName())

Get a pile of files

There are a a number of options for this method – see this article for examples and details Getting a pile of files from Google Drive with Apps Script

Links

github

IDE

library: 16NWIRmwJJY_wN4erx_QZA36_ssaB2GiKDPYebj7fjBU1SpVQlo9N_RA7

• Getting ‘a pile of files’ from Google Drive with Apps Script