PHP integration with Google Drive API to retrieve folder hierarchy in tree structure

Other Questions Google drive
1

I’m working on a PHP project where I need to integrate with Google Drive API. My goal is to establish a connection to Google Drive, fetch all the folders from a user’s drive, and then organize them into a hierarchical tree structure.

I’ve been struggling with understanding the proper authentication flow and how to use the Google Drive API effectively. Once I get the folder data, I also need help with the logic to arrange these folders in a parent-child relationship that represents the actual folder structure in Google Drive.

Here’s a basic example of what I’m trying to achieve:

<?php
class DriveManager {
    private $client;
    private $service;
    
    public function authenticate($credentialsPath) {
        // Need help with authentication setup
    }
    
    public function fetchFolders() {
        // Retrieve all folders from drive
    }
    
    public function buildFolderTree($folderList) {
        // Convert flat list to hierarchical structure
        return $treeStructure;
    }
}

$manager = new DriveManager();
$manager->authenticate('path/to/credentials.json');
$folders = $manager->fetchFolders();
$tree = $manager->buildFolderTree($folders);
?>

What’s the best approach to handle the OAuth2 authentication and API calls? Also, how should I structure the tree-building algorithm to maintain the correct parent-child relationships?

2

i kno the oauth flow is a bit tricky, but u’ll get it! make sure u have the Drive API enabled and download ur credentials JSON file. for building that tree structure, try using recursion to link parent IDs – it’s def easier than dealing with nested loops.

3

Been working with Google Drive API for a while and here’s what helped me most: handle token refresh properly. Access tokens die after an hour, so you need refresh token logic in your authenticate method. For building folder trees, I do two passes - way more efficient. First pass creates all folder objects with metadata, second pass links the parent-child relationships. Heads up: some folders have multiple parents in Google Drive. This’ll mess up your tree if you’re not ready for it. When querying folders, use ‘mimeType=“application/vnd.google-apps.folder”’ to filter out files. No point pulling unnecessary data. Make sure your buildFolderTree method handles orphaned folders too. Sometimes the API returns folders whose parents you can’t access due to permissions.

4

Authentication gets way easier once you get the flow. Set up your Google Client with the credentials file and make sure the redirect URI is handled right. For the tree structure, I store folders in an associative array using their IDs as keys. Then I iterate through and match parent IDs to build the hierarchy. Here’s the key thing - Google Drive folders have a ‘parents’ property with the parent folder ID. When you’re fetching folders, specify which fields you need in the API call so you don’t pull unnecessary data. The recursive approach works great, but if you’re dealing with huge folder structures, try a flat-to-tree conversion with references instead - it’s faster.