An introduction to YQL for hackers at the open hack day in London, talking about code demos at http://isithackday.com/hacks/ohd-london/

1. Remixing web data for your hacks
the easy way
YQL – the can opener of the web

2. Hacking together systems
in 24 hours is a lot of fun.

3. But you want to spend that
time thinking about the
interface.

4. And not how you get to the
right data in the right
format.

5. The web is full of juicy and
long lasting data.
hquot;p://www.flickr.com/photos/clspeace/162336973/

6. And there is a lot of it
around.
hquot;p://www.flickr.com/photos/tudor/2981410947/

7. However, our attempts to
get to it can be clumsy.
hquot;p://www.flickr.com/photos/lumachrome/2140368742/

8. What we need is an easy
way to get to that data.
hquot;p://www.flickr.com/photos/carey@lden/115435226/

9. We had a way to do that
for quite a while now.

10. http://pipes.yahoo.com/

11. Pipes, however is high end
technology…
hquot;p://www.flickr.com/photos/axio/2346342672/

12. We’re developers, not
interface users.
hquot;p://www.flickr.com/photos/codepo8/2278641937/

13. So for a long time people
asked Yahoo for a
command line version of
pipes.
Can we have one?

14. Yes, we can!

15. The Yahoo Query
Language, or short YQL is a
unified interface language
to the web.
http://developer.yahoo.com/yql/

16. Using YQL, accessing the
web and its services
becomes as easy as SQL:
select {what} from
{service} where
{condition}

17. Say you want kittens in
your hack (who doesn’t?)
select * from
flickr.photos.search
where text=quot;kittenquot;

18. Say you want kittens in
your hack (who doesn’t?)

19. Say you only want 5 kittens
select * from
flickr.photos.search
where text=quot;kittenquot;
limit 5

20. Say you only want 5 kittens

21. Nice, but where can you
get this?

22. YQL is a REST API in itself,
and it has two endpoints.

23. The public endpoint does
not need any
authentication.
http://query.yahooapis.com/v1/
public/yql?q={query}
&format={format}

24. The private endpoint needs
oauth authentication.
http://query.yahooapis.com/v1/
yql?q={query}
&format={format}
hquot;p://developer.yahoo.com/yql/guide/
authoriza@on‐access.html

25. Output formats are XML or
JSON.
JSON also allows for a
callback parameter to use
the output directly as
JSON-P.

26. http://query.yahooapis.com/v1/public/yql?
q=select%20*%20from flickr.photos.search
%20where%20text=%22kitten%22limit
%205&format=json&callback=meow

28. You can mix and match
several web services using
the in() command.

29. Guess what this does:
select * from
flickr.photos.info where
photo_id in (select id from
flickr.photos.search where
woe_id in (select woeid from
geo.places where
text='london,uk') and
license=4)

30. Find London, UK, without a
doubt.
select * from
flickr.photos.info where
photo_id in (select id from
flickr.photos.search where
woe_id in (select woeid from
geo.places where
text='london,uk') and
license=4)

31. Find Photos of London, UK
select * from
flickr.photos.info where
photo_id in (select id from
flickr.photos.search where
woe_id in (select woeid from
geo.places where
text='london,uk') and
license=4)

32. Find Photos of London, UK
with a “By” CC license
select * from
flickr.photos.info where
photo_id in (select id from
flickr.photos.search where
woe_id in (select woeid from
geo.places where
text='london,uk') and
license=4)

33. Give me everything you
know about these photos.
select * from
flickr.photos.info where
photo_id in (select id from
flickr.photos.search where
woe_id in (select woeid from
geo.places where
text='london,uk') and
license=4)

34. Using a command like this
and some out-of-the-box UI
elements like Yahoo Maps
and the YUI carousel, you
can build something *very*
quickly.

35. http://isithackday.com/hacks/cantine/
index.php?loc=covent+garden

36. Instead of selecting all the
information you can also
limit the results:
select name,url from
upcoming.venue where metro_id
in (select id from
upcoming.metro where
search_text=quot;stokeyquot;)

37. select name,url from
upcoming.venue where metro_id in
(select id from upcoming.metro
where search_text=quot;stokeyquot;)

38. The diagnostics part of the returned
data shows you what happened and
how long it took

39. Here’s what Yahoo offers you in this
format:
flickr.photos.exif local.search mybloglog.community.find
flickr.photos.info music.ar0st.id mybloglog.member
flickr.photos.interes0ngness music.ar0st.popular mybloglog.member.contacts
flickr.photos.recent music.ar0st.search mybloglog.member.newwithcontacts
flickr.photos.search music.ar0st.similar mybloglog.member.newwithme
flickr.photos.sizes music.release.ar0st mybloglog.members.find
flickr.places music.release.id mybloglog.stats.find
flickr.places.info music.release.popular upcoming.category
geo.places music.release.search upcoming.country
geo.places.ancestors music.track.id upcoming.events
geo.places.belongtos music.track.popular upcoming.events.bes0nplace
geo.places.children music.track.search upcoming.groups
geo.places.neighbors music.video.category upcoming.metro
geo.places.parent music.video.id upcoming.state
geo.places.siblings music.video.popular upcoming.user
geo.placetypes music.video.search upcoming.venue
gnip.ac0vity music.video.similar

40. Here’s what Yahoo offers you in this
format:
search.images search.images search.images
search.news search.news search.news
search.siteexplorer.inlinks search.siteexplorer.inlinks search.siteexplorer.inlinks
search.siteexplorer.pages search.siteexplorer.pages search.siteexplorer.pages
search.spelling search.spelling search.spelling
search.suggest search.suggest search.suggest
search.termextract search.termextract search.termextract
search.web search.web search.web
social.connec0ons social.connec0ons social.connec0ons
social.contacts social.contacts social.contacts
social.presence social.presence social.presence
social.profile social.profile social.profile
social.updates social.updates social.updates
weather.forecast weather.forecast weather.forecast
yahoo.iden0ty yahoo.iden0ty yahoo.iden0ty
yap.setsmallview yap.setsmallview yap.setsmallview

41. You want even more?
http://www.flickr.com/photos/verylastexcitingmoment/3123597774/

42. Alright, how about this?
json
atom
microformats
csv
rss
feed
xml
html

43. Telegraph’s headlines
anyone?
select * from html where
url='http://www.telegraph.co.uk/'
and xpath='//h3/a'

44. Telegraph’s headlines
anyone?

45. You can dynamically create
YQL queries to collate
several sources…

46. Then use cURL to pull them
off the web with one single
http request!

47. YQL caches and
compresses the results for
you.
Pretty easy, isn’t it?

48. Here’s another fun part:
Anyone can be part of the
YQL interface.

49. All we need the data
provider to do is to create a
schema that explains their
data structure.
http://developer.yahoo.com/yql/guide/
yql-opentables-chapter.html

50. And people do…
amazon nmm
bitly nyt
delicious opensocial
dopplr search
etsy shopping
friendfeed social
github twi?er
Greader update.groovy
guardian weather
imdb wesabe
iploca0on whitepages
las>m yahoo
nestoria yelp
ne>lix zillow
http://github.com/spullara/yql-tables/tree/master

51. For example the national
maritime museum:
select * from
nmm.archive.search where
searchterm=‘horatio nelson'

52. select * from
nmm.archive.search where
searchterm=‘horatio nelson'

53. That’s pretty cool –
allowing anyone to be part
of this interface.

54. The only shame is that you
can’t do all the things in
YQL that you can do in
Pipes – for example string
manipulation.

55. We wondered how to make
this possible.
One thing we didn’t want
to sacrifice is the simplicity
of the language itself.

56. So instead of inventing an
own language, we decided
to piggy-back on one you
already know.

57. YQL execute allows you to
embed JavaScript in the
open table schema that
runs on the YQL server and
converts the data for you.
http://developer.yahoo.com/yql/guide/yql-
execute-chapter.html

58. For example you can
augment an existing service
to do something different.

59. The following example
adds a rank to search
results.
http://www.yqlblog.net/samples/searchrank.xml

62. Stored as XML this can be
used in a YQL query:
use 'http://yqlblog.net/
samples/searchrank.xml' as
searchrank;
select * from searchrank where
query='pizza' and dispurl like
'%pizzahut%'

64. Anyways, the *easiest* way
to start with YQL is to use
the console.
http://developer.yahoo.com/yql/console/

74. Of course, you can also
spend half the hack day
reading API docs 

75. Check out some code
examples on.
http://isithackday.com/hacks/ohd-london

76. THANKS!
Chris Heilmann
http://twitter.com/codepo8