1. Using the Memento
MediaWiki Extension to
Avoid Spoilers
Shawn M. Jones
sjone@cs.odu.edu
Old Dominion University

2. How many of us watch?

3. Getting Info On Our Favorite Fiction
All of these are wikis!
All of these wikis run MediaWiki!

4. The Problem
We haven’t caught up because
of a job/ailing mother/bar
crawl/life.

5. The Problem
Wait, he’s dead?
How do we avoid
these spoilers?
We haven’t caught up because
of a job/ailing mother/bar
crawl/life.

6. Current “Solution”
Post a big SPOILER ALERT on the page
I haven’t caught
up. Is this Wiki
even useful to
me until I catch
up?
I’m afraid to use
this site now.
Site owners may be losing ad revenue because visitors turn away.

7. The solution
RFC 7089 describes the Memento Protocol
Memento Chrome Extension
by Los Alamos National Laboratory (LANL)
User installs in browser
Memento MediaWiki Extension
by Old Dominion University and LANL
Site administrator installs in MediaWiki

8. Simplified Memento Overview

9. DEMO
• Let’s avoid some spoilers with A Song Of Ice
and Fire…
http://ws-dl-
05.cs.odu.edu/demo/index.php/Kevan_Lanniste
r
https://www.youtube.com/watch?v=tb0g5D5LTi
U

10. DEMO Screenshots
We want to find information about Kevan Lannister, but haven’t read the book A
Dance with Dragons yet. We set the Memento Chrome Extension prior to the
release of that book: June 29, 2011.

11. DEMO Screenshots
We use the Memento Chrome Extension to request a revision of the page close to, but
not over, our requested date.

12. DEMO Screenshots
And we get the revision of the page closest, but not over, the date requested.

13. DEMO Screenshots
And, as you can see, this revision of the page has no information about
A Dance With Dragons.

14. DEMO Screenshots
And that’s not all… I can browse the rest of the site, spoiler-free.

15. DEMO Screenshots
Here’s the past revision of the page about Tommen Baratheon, as linked to, from
the Kevan Lannister page, and still close to, but not over, our requested date.

16. Summary
• Wikis contain the past revision of ever page
• Today’s fiction has given rise to fan wikis
• For topics that have evolving information,
Memento can provide a way to avoid spoilers
• If the Memento MediaWiki Extension is
installed on your fan-based wiki, then users
with the Memento Chrome Extension will be
able to avoid spoilers!

17. Resources
• Memento Protocol: http://tools.ietf.org/html/rfc7089
• Memento Website: http://www.mementoweb.org/
• Memento MediaWiki Extension:
http://www.mediawiki.org/wiki/Extension:Memento
• Memento Chrome Extension:
http://bit.ly/memento-for-chrome
• More details:
http://ws-dl.blogspot.com/2013/12/2013-12-18-avoiding-spoilers-
with.html
• Demo:
https://www.youtube.com/watch?v=ciClYjTnscs
• Contact me: sjone@cs.odu.edu

18. Backup slides

19. Other uses for the Memento
MediaWiki Extension
Evolving laws and legal discourse
Past software contributions
(Folding@Home)
Changing relationship
between organizations
(ICANN vs. Verisign)

20. Memento Extension vs. Manually
Getting Page Revision
Why do it when Memento will do it for you?
This is very time
consuming.
Memento let’s you
browse through the
whole web with a given
date!

21. Memento Extension vs. MediaWiki API
JSON:
{"revid":607345961,"parentid":607210719,"timestamp":"2014-05-06T16:07:52Z”}
XML:
<rev revid="607519915" parentid="607345961" user="Marklemagne"
timestamp="2014-05-07T19:00:26Z"/>
Only a custom MediaWiki client can turn these oldid entries into
URIs.
Memento is a web standard way of accessing old web resources
and is already implemented for many different applications (web
archives, etc.)

22. Memento Extension vs. MediaWiki API
Link: <http://ws-dl-05.cs.odu.edu/demo-302-recommended-
relations/index.php/Daenerys_Targaryen>; rel="original latest-version",
<http://ws-dl-05.cs.odu.edu/demo-302-recommended-
relations/index.php/Special:TimeGate/Daenerys_Targaryen>; rel="timegate",
<http://ws-dl-05.cs.odu.edu/demo-302-recommended-
relations/index.php/Special:TimeMap/Daenerys_Targaryen>; rel="timemap";
type="application/link-format"; from="Sun, 22 Apr 2007 15:01:20 GMT"; until="Fri, 27
Sep 2013 20:48:24 GMT",
<http://ws-dl-05.cs.odu.edu/demo-302-recommended-
relations/index.php?title=Daenerys_Targaryen&oldid=1499>; rel="first memento";
datetime="Sun, 22 Apr 2007 15:01:20 GMT",
<http://ws-dl-05.cs.odu.edu/demo-302-recommended-
relations/index.php?title=Daenerys_Targaryen&oldid=107643>; rel="last memento";
datetime="Fri, 27 Sep 2013 20:48:24 GMT"
Memento also follows the RESTful principle of “follow
your nose”, indicating additional resources to access
from here.

23. Memento Extension vs. Internet
Archive
The Internet Archive
only gets some of
the revisions of a
given page.
MediaWiki has all of
the revisions of a
given page.

24. Memento Extension vs. Other
MediaWiki Time Travel Extensions
While these extensions just work for MediaWiki,
Memento works for the entire web.
With the Memento extensions, one can browse
the entire web spoiler free by seamlessly
accessing web archives and other resources
through Memento.

25. Sample URI-R (Step 1) HTTP Response
HTTP/1.1 200 OK
Date: Sun, 25 May 2014 21:39:02 GMT
Server: Apache
X-Content-Type-Options: nosniff
Link: http://ws-dl-05.cs.odu.edu/demo/index.php/Daenerys_Targaryen;
rel="original latest-version",
http://ws-dl-
05.cs.odu.edu/demo/index.php/Special:TimeGate/Daenerys_Targaryen;
rel="timegate",
http://ws-dl-
05.cs.odu.edu/demo/index.php/Special:TimeMap/Daenerys_Targaryen;
rel="timemap”; type="application/link-format”
Content-language: en
Vary: Accept-Encoding,Cookie
Cache-Control: s-maxage=18000, must-revalidate, max-age=0
Last-Modified: Sat, 17 May 2014 16:48:28 GMT
Connection: close
Content-Type: text/html; charset=UTF-8

26. Sample URI-G (Step 2) HTTP Response
HTTP/1.1 302 Found
Date: Sun, 25 May 2014 21:43:08 GMT
Server: Apache
X-Content-Type-Options: nosniff
Vary: Accept-Encoding, Accept-Datetime
Location: http://ws-dl-
05.cs.odu.edu/demo/index.php?title=Daenerys_Targaryen&oldid=1499
Link: <http://ws-dl-
05.cs.odu.edu/demo/index.php/Special:TimeMap/Daenerys_Targaryen>;
rel="timemap”; type="application/link-format",
<http://ws-dl-05.cs.odu.edu/demo/index.php/Daenerys_Targaryen>;
rel="original latest-version”
Connection: close
Content-Type: text/html; charset=UTF-8

27. Sample URI-M (Step 3) HTTP Response
HTTP/1.1 200 OK
Date: Sun, 25 May 2014 21:46:12 GMT
Server: Apache
X-Content-Type-Options: nosniff
Memento-Datetime: Sun, 22 Apr 2007 15:01:20 GMT
Link: <http://ws-dl-05.cs.odu.edu/demo/index.php/Daenerys_Targaryen>;
rel="original latest-version”,
<http://ws-dl-
05.cs.odu.edu/demo/index.php/Special:TimeGate/Daenerys_Targaryen>;
rel="timegate”,
<http://ws-dl-
05.cs.odu.edu/demo/index.php/Special:TimeMap/Daenerys_Targaryen>;
rel="timemap”; type="application/link-format”
Content-language: en
Vary: Accept-Encoding,Cookie
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Cache-Control: private, must-revalidate, max-age=0
Connection: close
Content-Type: text/html; charset=UTF-8