A walkthrough and more details are available on Google Drive SDK docs.

1. Create a new Google App Engine application

2. Clone DrEdit's git repo and init submodules:

   git clone [email protected]:googledrive/dredit.git && cd dredit
   git submodule init
   git submodule update --recursive
   

3. Create an API project in the Google APIs Console.

4. Select the Services tab in your API Project, and enable the Drive API and Drive SDK.

5. Select the API Access tab in your API Project, click Create an OAuth 2.0 client ID.

6. In the Branding Information section, provide a name for your application (e.g. "DrEdit"), and click Next. Providing a product logo or a homepage URL is optional.

7. In the Client ID Settings section, do the following:

   1. Select Web application for the Application type
   2. Click the more options link next to the heading, Your site or hostname.
   3. List the URI of the Google App Engine application created in step 1 (i.e. https://your_app_id.appspot.com) in the Authorized Request URIs and JavaScript Origins fields.
   4. Click Create Client ID.

8. Register DrEdit as described in Enable the Drive SDK using the following values:

   1. Set the default MIME types text/plain and text/html, and the default extensions txt and html.
   2. Ensure that the set of redirect URIs includes the URI of the Google App Engine application created in step 1 (i.e. https://your_app_id.appspot.com). The same URL must be provided for the Open URL and Create URL fields.
   3. Add the Google API Scopes of https://www.googleapis.com/auth/userinfo.email, https://www.googleapis.com/auth/userinfo.profile and https://www.googleapis.com/auth/drive.install.
   4. For icons, use the example icons provided in the chromewebstore directory.

9. Download and install the Google Plugin for Eclipse

10. In Eclipse, create a new Google App Engine project, unchecking Use Google Web Toolkit and Generate project sample code.

11. Copy the contents of the java/ directory to the root of the Google App Engine project.

12. Using the Google Plugin for Eclipse, add the Drive API v2 and the OAuth API v2 to the project.

13. Edit war/WEB-INF/client_secrets.json to replace the client_id, client_secret, and redirect_uris with the values from the Google APIs Console under the API Access tab for the project.

14. Edit war/WEB-INF/appengine-web.xml and replace the value for the application setting with the identifier of the new Google App Engine application created in step 1.

15. Edit Scripts\app.js and replace YOUR_APP_ID with the value of the CLIENT_ID from the Google APIs Console under the API Access tab for the project.

16. Click the App Engine deploy button in Eclipse, following the instructions described in the Google App Engine documentation to upload the application to Google App Engine.

17. Test the application.

18. Continue reading to find out how DrEdit is constructed, and how to modify it to work for your own application's needs.