APIs and their use in libraries. For the 2011 Library Technology Conference at Macalester College in St. Paul, MN. March 17, 2011.

1. APIs, Web Services, and
Mashups
What they are and how they can be used
by Shane Nackerud
University of Minnesota Libraries
snackeru@umn.edu

2. Agenda
What is an API?
What is a Web
Service?
What is a mashup?
What are some
examples?
Look at an API
A little code ...

3. What is an API?
“An application programming interface (API) is a
particular set of rules and specifications that a software
program can follow to access and make use of the
services and resources provided by another software
program.”
http://en.wikipedia.org/wiki/Application_programming_interface

5. Break it down
Interface for software apps and servers
Application to Application interaction and exchange of
data
Real time communication and data exchange
Allows software programs to interact with other
software programs data through means other than the
normal main interface

8. Twitter API
Tweetdeck
Facebook API

9. Web Service
TweetDeck is a client application
Web services are APIs that work primarily through the
web, web servers, or a network
Server to server APIs
Google Maps API is a good example

11. Add the code to include the Google Maps API:
<script src="http://maps.google.com/maps?
file=api&amp;v=2&amp;
key=ABQIAAAA6JBCuUc9hZU7FVhzHksqsxSFThBmb0Wg
HbIO-PDXl2-6njl54hRynCyYgHJZbbA1K1ChW7zdIcbMwA"
type="text/javascript"></script>

12. Add the code to include library locations data and mark
them on the map:
var request = GXmlHttp.create();
request.open("GET", "/libinc/libraries.xml", true);
request.onreadystatechange = function() {
if (request.readyState == 4) {
var xmlDoc = GXml.parse(request.responseText);
// obtain the array of markers and loop through it
var markers =
xmlDoc.documentElement.getElementsByTagName("mar
ker");

13. Library Location XML Data:
<markers>
<marker lat="44.970971" lng="-93.243633" html="Ames Library (in
Wilson Library)<br />309 19th Ave. S.<br />
Minneapolis, MN 55455<br />612-624-4857<br /><a href='http://
www.lib.umn.edu/site/fetch_hours.phtml?LibID=2'>
Hours</a><br />" label="Ames Library (in Wilson Library)"/>
<marker lat="44.973191" lng="-93.243083" html="Andersen
Library<br />222 21st Ave. S.<br />
Minneapolis, MN 55455<br />612-625-9825<br /><a href='http://
www.lib.umn.edu/site/fetch_hours.phtml?LibID=14'>
Hours</a><br />" label="Elmer L. Andersen Library"/>

14. Mashups
A website that combines information/data from more
than one source creating an integrated experience
Speaking of Google Maps ...

16. http://earthquakes.tafoni.net/

17. http://trendsmap.com

18. http://whatwasthere.com/

20. Types of APIs
Interface APIs
Google Maps
Bing Maps
Yahoo Maps
Open Street Maps
Data APIs

21. Why?
Developers
Get at important data/services not locally held
Quicker creation of common tasks and services
Learn more about their users
Create whizz-bang gizmos and gadgets

22. Why?
Providers
Create more visibility for services offered
Create more traffic for services offered
Make money (some APIs aren’t free)
Make customers happy and be amazed at how they
use your data

23. OCLC Web Services
http://www.oclc.org/developer/services

24. WorldCat Search API

25. xISSN + WorldCat Search API + Catalog API

26. xISSN + WorldCat Search API + Catalog API

27. xISSN + WorldCat Search API + Catalog API

28. QuestionPoint Knowledgebase

29. AlephX + xISBN

30. AlephX + xISBN

31. AlephX + Amazon Recommedations API + xISBN

32. AlephX + Amazon Recommedations API + xISBN

33. Query Protocol Record Formats

34. Query Protocol Record Formats
xISBN - can query the API through REST and OpenURL

35. Query Protocol Record Formats
xISBN - can query the API through REST and OpenURL
Data - comes back as XML, JSON, TEXT, PHP,
HTML

36. Query Protocol Record Formats
xISBN - can query the API through REST and OpenURL
Data - comes back as XML, JSON, TEXT, PHP,
HTML
Say what?

37. REST
Representational State Transfer (REST) is a style of
software architecture for distributed hypermedia
systems such as the World Wide Web.
For our purposes: RESTful APIs use HTTP to request
the data
Data is requested through a URL call
Similar to OpenURL

38. xISBN REST request
http://xisbn.worldcat.org/
webservices/xid/isbn/
0596002815?format=xml

40. xISBN Metadata Request
http://xisbn.worldcat.org/
webservices/xid/isbn/
0596002815?
method=getMetadata&format=
xml&fl=*

42. More examples at:
http://xisbn.worldcat.org/xisbnadmin/doc/api.htm

43. xISBN API xisbnparse.xsl
0596002815
book.php

44. xISBN API xisbnparse.xsl
0596002815
book.php

45. xISBN API xisbnparse.xsl
0596002815
book.php
xHTML page

46. book.php?isbn=0596002815

47. <?php
$xsl = new DomDocument;
$xsl->load("xisbnparse.xsl");
$xmloutput = new DomDocument;
$xmloutput->load("http://xisbn.worldcat.org/
webservices/xid/isbn/$isbn?
method=getMetadata&format=xml&fl=*");
$xsltproc->importStylesheet($xsl);
echo $xsltproc->transformtoXML($xmloutput);
?>

48. • U of M Libraries Mobile
• AlephX, PrimoX, X-Services
• PHP, XSLT

52. http://www.lib.umn.edu/libdata/rest/librestapis.html

53. AlephX + ERes RSS Feed

54. Course Specific
Resource
Suggestions API
Subject Guide API
Course Reserves API

55. In conclusion
Old and Busted New Hotness
Web Server Web Server
API
API
API
Database Database

56. In conclusion
With APIs the Web can truly become a networked
database (of sorts)
Always ask a vendor if the application has an API
Start noticing APIs that are available and think ...
Be a provider, too