The document outlines Victor Gau's lightning talk on accessing the social graph using R. It discusses the social graph and Graph API, explains what JSON is and how to parse it in R. It provides examples of using the Graph API to retrieve public profile data for Facebook pages and accounts. The talk also covers how to access the social graph directly from R using the RCurl and rjson packages and recommends the Facebook Developer Tools for exploring the Graph API and retrieving access tokens.

1. Victor Gau
Lightning Talk @ Kaohsiung useR! Meetup
2014/05/05

2. Outline
 What is the Social Graph?
 Graph API Explained
 What is JSON?
 “R” to Parse JSON
 Spider Revisited
 “R” to Access the Social Graph
 Using Facebook Developer Tools
 Topics for Sharing Next Time

3. What is the Social Graph?
Business Insider: So What The Heck Is The 'Social Graph'
Facebook Keeps Talking About?

4. Graph API Explained
 APIs for accessing social graph
 HTTP requests are sent to access the social
graph (the responses are in JSON format)
 most requests are sent to
https://graph.facebook.com
 requests for videos are sent to https://graph-
video.facebook.com
 https://developers.facebook.com/docs/gr
aph-api/quickstart/v2.0

5. Graph API Explained
https://www.facebook.com/HTC

6. Graph API Explained
https://graph.facebook.com/HTC

7. What is JSON?
 JavaScript Object Notation
 http://en.wikipedia.org/wiki/JSON

8. “R” to Parse JSON
 Install “rjson” package
 install.packages(“rjson”)
 Load “rjson” package
 library(rjson)
 Functions to use:
 fromJSON()
 toJSON()
 newJSONParser()

9. Sample Code - Reading JSON
data = '{
"firstName": "John",
"lastName": "Smith",
"isAlive": true,
"age": 25,
"height_cm": 167.64,
"address": {
"streetAddress": "21 2nd Street",
"city": "New York",
"state": "NY",
"postalCode": "10021-3100"
},
"phoneNumbers": [
{ "type": "home", "number": "212 555-1234" },
{ "type": "fax", "number": "646 555-4567" }
]
}'
person <- fromJSON(data)
person$firstName
person$lastName

10. Spider Revisited
# Load Required Packages
library(RCurl)
library(XML)
# Get Page Source
html = getURL("http://www.ptt.cc/bbs/R_Language/index.html")
# Parse to get information using XPath
xml = htmlParse(html)
Xpath = "//div[@class='title']/a//text()"
titles = xml [Xpath]

11. “R” to Access the Social Graph
# Load Required Packages
library(RCurl)
library(rjson)
# Retrieve Data (in JSON format)
data = getURL("https://graph.facebook.com/htc",
ssl.verifypeer = FALSE )
# Read JSON
htc <- fromJSON(data)

12. “R” to Access Social Graph
 Access Token would be needed for
certain content in social graph most of
the time.
 Access Token can be retrieved by using
graph explorer from Facebook
Developer Tools.
 Sample URL for retrieving information
with Access Token:
 http://graph.facebook.com/me/friends?acce
ss_token=XDFAFDFXXXXXXXDAFDA

13. Using Facebook Developer Tools
https://developers.facebook.com/tools/

15. Topics for Sharing Next time
 Authentication
 Social Plugins
 Open Graph Protocol
 FBML
 XFBML
 FQL
 …