Gdata Moscow

Google Data APIs Eric Bidelman 28 October, 2008

Quick poll

Why should you care?

Why should you care? • 15 Google Data APIs, 40+ others - Maps, AJAX APIs, OpenSocial (gadgets), Gears, and many more

• Standard protocols - HTTP, RESTful APIs - Atom Publishing Protocol (XML), JSON, etc. - OAuth

• Easy development - most products have APIs  no need to start from scratch  - open source client libraries

• Gain large user base - build on top of popular Google services - mashups with other web services

Wide variety of services

Wide variety of services

Today’s Agenda • Demos - web applications, gadgets, mashups - desktop samples

• Google Data Protocol - APP, XML, REST, HTTP - under the hood: raw protocol demo

• Authentication …because private data is more interesting

• AJAX Search APIs • Questions & Answers

LIVE Demos!

Demos - PHP YouTube vs JSON YouTube YouTube Video Browser (PHP) APIs: YouTube Data API PHP client library http://www.googlecodesamples.com/youtube/php/YouTubeVideoBrowser/

YouTube Video Browser (JSON) APIs: YouTube Data API JavaScript (alt=json-in-script) http://www.googlecodesamples.com/youtube/js/YouTubeVideoBrowser/

Demos – Book Search Data API Book Search Browser APIs: Book Search Data API PHP client library, JavaScript http://www.googlecodesamples.com/books/php/BooksBrowser/

Demos - Mashing up Google Calendar + Contacts

Calendar Event Creator APIs: Contacts & Calendar Data APIs, App Engine Python client library http://calendar-contacts.appspot.com/

Demos – Installed Applications DocList Uploader APIs: Documents List Data API .NET client library

http://code.google.com/apis/gdata/articles/doc_list_uploader.html

Demos – Google Data Gadgets Blogger Gadget APIs: Blogger Data API, OAuth, OpenSocial JavaScript client library http://gdata-samples.googlecode.com/svn/trunk/gadgets/blogger/blogger_gadget.xml

Google Data Protocol

Protocol - Atom Syndication Format Feeds and Entries … … <entry> http://picasaweb…/entry/…albumid/5141841 2008-05-08T04:15:41.000Z <entry>… <entry>…

Protocol - HTTP Communication

Create POST /calendar/feeds/default/allcalendars/full 201 Created

Retrieve GET /calendar/feeds/default/allcalendars/full 200 OK

Update PUT /calendar/feeds/default/allcalendars/full/{ID} 200 OK

Delete DELETE /calendar/feeds/default/allcalendars/full/{ID} 200 OK

Protocol - HTTP Status Codes

200 201 304 400 401 403 404 409 500

OK CREATED NOT MODIFIED BAD REQUEST UNAUTHORIZED FORBIDDEN NOT FOUND CONFLICT INTERNAL SERVER ERROR

Protocol - Google Data API Extensions • Extended data model , , <media:thumbnail> Feature

• Batch operations • Authentication - ClientLogin - desktop apps - AuthSub - web apps - OAuth - open standard

Google  Data

Atom

RSS 2.0

Syndication Format

Y

Y

Y

Queries

Y

N

N

Updates

Y

Y

N

Optimistic  Concurrency

Y

N

N

Authentication

Y

N

N

• Alternate formats - alt=rss, alt=json, alt=json-in-script, alt=kml (Picasa Web)

Authentication

Authentication - Overview Problems: Authentication is difficult • Private resources • Security considerations Solution: Let Google handle it! • Authorization not Authentication • Tokens not credentials • User grants/denies access to their private data

Authentication - ClientLogin • Installed/desktop applications • Username/password • Access to a single service • Tokens expire in ~2 weeks • CAPTCHAs POST /accounts/ClientLogin HTTP/1.0 Content-type: application/x-www-form-urlencoded accountType=HOSTED_OR_GOOGLE [email protected] &Passwd=pa$$word &service=cl &source=Google-CalExample-v1.0

Authentication - AuthSub • Web applications • Authorization - your website  Google  your website

• Tokens - single-use or multiple-use (never expire) - scoped access to data - revoke tokens manually / programmatically

• Three ‘modes’ 1. non-registered, non-secure 2. registered, non-secure 3. registered & secure (API requests are digitally signed) https://www.google.com/accounts/AuthSubRequest ?scope=http://www.google.com/calendar/feeds &session=1&secure=0 &next=http://www.example.com

Authentication - OAuth • Similar to AuthSub - single mode: ALL requests must be signed

• Web applications • Open standard - growing in popularity (Yahoo, MySpace, AOL) - open source libraries available: oauth.net - reuse authentication code from another project

Protocol demonstration

Protocol demonstration - OAuth Playground

OAuth Playground 1. 2. 3. 4. 5.

Authorization to the Contacts Data API GET retrieving a user’s contacts POST create a new contact entry PUT update the entry DELETE remove the contact

http://www.googlecodesamples.com/oauth_playground/

Making life easier - Client Libraries

• Java • .NET • Python • PHP • Objective-C • JavaScript

AJAX Search APIs

AJAX Search APIs

• Google is known for search! google.search.LocalSearch google.search.WebSearch google.search.VideoSearch google.search.BlogSearch

google.search.NewsSearch google.search.ImageSearch google.search.PatentSearch google.search.BookSearch

• Compatibility - Firefox 1.5+, IE 6+, Safari, Opera 9+, Google Chrome

• Common loader google.load('search', '1'); google.load('gdata', '1.x', {packages:['blogger']}); google.load('maps', '2.s'); google.load('earth', '1'); google.load('jquery', '1.2.6', {uncompressed:true});

AJAX Search APIs – Basic Example <script src="http://www.google.com/jsapi?key=ABQIBX..."> <script type="text/javascript"> google.load('search', '1', {'language' : 'ru'}); function initialize() { var gSearch = new google.search.SearchControl(); var options = new google.search.SearcherOptions(); options.setExpandMode( google.search.SearchControl.EXPAND_MODE_OPEN); gSearch.addSearcher(new google.search.WebSearch(), options); gSearch.draw(document.getElementById('searchcontrol')); //gSearch.execute('LOL cats'); // execute search automatically } google.setOnLoadCallback(initialize); …

AJAX Search APIs – Customizations

• Linear or tabbed display var drawOpts = new google.search.DrawOptions(); drawOpts.setDrawMode( google.search.SearchControl.DRAW_MODE_TABBED);

• Choose where results are displayed var options = new google.search.SearcherOptions(); options.setRoot( document.getElementById('somewhere_else')); searchControl.addSearcher( new google.search.WebSearch(), options);

• CSS styling google.load('search', '1', {'nocss' : true});

AJAX Search APIs – Non-JavaScript

… not just JavaScript - REST, JSON - Examples in Flash, PHP, Java curl --silent --referer http://www.example.com \ "http://ajax.googleapis.com/ajax/services/search/web\ ?v=1.0&q=Beijing%20Olympics"

Questions & Answers

Resources

Google Data APIs: http://code.google.com/apis/gdata/ OAuth Playground and other LIVE samples: http://www.googlecodesamples.com/ AJAX APIs: http://code.google.com/apis/ajax