August 27, 2013

How to get all your Google Drive folders and URLs with GAS JSONP servlet

Using all the folders of a Google Drive account as a collaboration point over an external web app sounds pretty convenient under certain scenarios, especially for web-based Centralized Business Management.

Apps Script makes this easy with Drive Services and with very little effort you can make a GAS JSONP servlet that query's and packs all the folder names and URLs in a single JSON string, this is specially useful if you are trying to merge different accounts over a single interface. You can get pretty creative about how to implement this.

To make your own GAS JSONP servlet to handle your G.Drive file names & URLs, create a new Google Apps Script project and copy the following code:

Depending on what you need, you might add more data about the folders, this are the most relevant methods:

1.- getAccess(email): Check the users rights on this folder:

2.- getDateCreated(): To know the date when the folder was created.

3.- getDescription(): To get the folders description.

4.- getId(): This one it's particularly useful when working with JSONP, you can use the padding to tell the servlet to do something to a specific folder using the getFolderById(id) method.

5.- getFiles(): It's possible to add all files inside each folder in our JSON package, just add another While cycle but inside the folder's while cycle, this way you get all the folders name, URLs and with all it's files names and URLs, always use parallel loading when using this, in most cases the servlet will take some time to parse all this data.

6.- getSize(): Get's the number of bytes used to store this folder in Drive, in case you need to calculate loads.

Here is a very basic script to call the servlet from your HTML, for testing purposes the prefix it's set to "alert" so the data will be displayed on a pop-up as soon as it loads. For real-life applications change the "alert" prefix to the name of the Javascript function responsible for parsing the JSON, I also recommend
using AngularJS to handle parallel data loading when calling different servlets.

The HTML already includes the URL of a fully working servlet, feel free to use it for testing, but before you can use it, you need to grant access to the servlet, this is a 1 time requirement and it's done by manually calling the servlet's URL:

Stay tuned for articles with more advanced uses of this approach, feel free to post your ideas, comments or suggestions.

Happy coding!