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Photo Frame Sample

This is a Node.js sample application for the Google Photos Library API.

This sample shows how to connect an app with Google Photos through OAuth 2.0 and display a user's photos and albums in an "online photo frame".

This app is built using Express.js and Material Design Lite.

App Overview

This web app is an online photo frame that allows users to load photos from a search, an album or the library and then show these images in a full screen slideshow.

Screenshots

Screenshot of photo frame Screenshot of login screen

Set up

Before you can run this sample, you must set up a Google Developers project and configure authentication credentials. Follow the get started guide to complete these steps:

  1. Set up a Google Developers Project and enable the Google Photos Library API.
  2. In your project, set up new OAuth credentials for a web server application. Set the authorized JavaScript origin to http://127.0.0.1 and the authorized redirect URL to http://127.0.0.1:8080/auth/google/callback if you are running the app locally.
  3. The console will display your authentication credentials. Add the Client ID and Client secret to the file config.js, replacing the placeholder values:
// The OAuth client ID from the Google Developers console.
config.oAuthClientID = 'ADD YOUR CLIENT ID';

// The OAuth client secret from the Google Developers console.
config.oAuthclientSecret = 'ADD YOUR CLIENT SECRET';

You are now ready to run the sample:

  1. Ensure Node.JS and npm are installed and available on your system. You need a recent Node.js version (v14 or later) to run this sample.
  2. Navigate to the directory of this sample: REST/PhotoFrame.
  3. Install dependencies: Run npm install,
  4. Start the app: Run node app.js.

By default, the app will listen on port 8080. Open a web browser and navigate to http://127.0.0.1:8080 to access the app.

Troubleshooting

Make sure that you have configured the Client ID and the Client secret in the configuration file config.js. Also check that the URLs configured for these credentials match how you access the server. By default this is configured for 127.0.0.1 (localhost) on port 8080.

You can also start the app with additional debug logging by setting the DEBUG environment variable to true. For example:

DEBUG=TRUE node app.js

API Use and code overview

The app is built using the Express.js framework and the ejs templating system.

First, the user has to log in via OAuth 2.0 and authorize the https://www.googleapis.com/auth/photoslibrary.readonly scope. (See the file config.js.) Once authenticated, photos are loaded into the photo frame via search or from an album.

The app is split into the backend (app.js) and the front end (static/...). The photo frame preview screen make AJAX requests to the backend to load a list of selected photos. Likewise, the album screen makes an AJAX request to the backend to load the list of albums that are owned by the user. The backend returns media items or albums directly from the Library API that are parsed and rendered in the browser.

Search

The search screen (/search) is loaded from a template file located at views/pages/search.ejs that contains the search form. When this form is submitted, the POST request is received in app.js in the handler app.post('/loadFromSearch', ...). The values sent in the form are used to prepare a [filter] object that is then submitted to the Google Photos Library API /search endpoint in libraryApiSearch(authToken, parameters).

The call to the API in libraryApiSearch(authToken, parameters) shows how to handle the nextPageToken to retrieve multiple pages of search results.

Albums

The album screen (/album) is loaded from a template file located at views/pages/album.ejs. When this screen is loaded, the browser makes a request to /getAlbums that is received by the server app.js in the handler app.get('/getAlbums', ...). The method libraryApiGetAlbums(authToken) is called to load the albums from the API. This method shows to handle the nextPageToken to retrieve a complete list of all albums owned by the user.

The retrieved [albums] are returned and displayed through the file static/js/album.js. Here the album objects are parsed and the title, cover photo and number of items are rendered on screen.

When an album is selected, the handler app.post('/loadFromAlbum', ...) receives the id of the album that was picked. Here, a search parameter is constructed and passed to libraryApiSearch(authToken, parameters) to load the images.

Displaying photos

Photos are displayed on the photo frame page of this app. The template file is located at views/pages/frame.ejs. When this page is loaded, a request is made to app.get('/getQueue', ...) to the server app.js.

This handler returns a list of the mediaItems the user has loaded into the frame through search or from an album. They are rendered for display by the browser through the file static/js/frame.js. Here the caption is constructed from the description and other media metadata. A thumbnail, scaled based on the original height and width, is used to render a preview initially while the image at full resolution is being loaded.