How to get total file count of a specific folder including subfolder - box-api

Question

I know there is NOT a direct way to get all files + folders of a hierarchy of BOX folder. we have to recursively get items of subfolders.
However, if I simply need a count estimation, is it possible to get the basic info?
The Transferring tool https://www.multcloud.com can estimate the file count firstly, after it is done, it will start the transferring. In my observation, it looks it also recursively iterates the folders, but how it can know the recursive has completed?
Thank you for any hints!

Answer 1

If your tool is executed on the same machine on different dates, you can maintain some "estimation data" (i.e. persist the number of files of certain directories in a run, and use this old number of files contained in a subtree as estimation values for further runs)

Answer 2

Hi finally found it is just a common question on how to determine a recursively iteration has completed. The other post helped a lot. How to detect completion of recursive asynchronous calls in javascript
With the hints, my code works well. The below is the script for reference. It can be converted to Promise. I have not tried, though.
function buildTreeNodes(boxTopFolderId){
function startBuild(){
//get the top folder info
box.folders.getItems(boxTopFolderId ,
function (err, data) {
var results = [];
results.finished = 0;
var len = data.entries.length;
if (err){
console.log(err);
}
else{
//iterate from the top folder
data.entries.forEach(function (item, index) {
// BOX of file or folder
var boxid = item.id;
// file or folder
var boxtype = item.type;
//item name
var boxname = item.name;
if(boxtype === 'folder'){
recursiveFolder(boxid,function(result){
results[index] = result;
if (++results.finished == len) {
//recursion done!
}
});
}else{
results[index] = item;
if (++results.finished == len) {
//recursion done!
}
}
}); //end for each
if(len == 0)
//recursion done!
}
});
}
function recursiveFolder(folderId,callback){
box.folders.getItems(folderId,
function (err, data) {
var results = [];
results.finished = 0;
var len = data.entries.length;
if (err){
console.log(err);
}
else{
//iterate from the top folder
data.entries.forEach(function (item, index) {
// BOX of file or folder
var boxid = item.id;
// file or folder
var boxtype = item.type;
//item name
var boxname = item.name;
if(boxtype === 'folder'){
recursiveFolder(boxid,function(result)
{
results[index] = result;
if (++results.finished == len) {
callback(results);
}
});
}
else{
results[index] = item;
if (++results.finished == len){
callback(results);
}
}
});
if(len == 0)
callback(results);
}
});
}
startBuild();
}