Mannheim

1
Mannheim

• Web 2.0 Systems Development

2
Plan

• Being an early-adopter
• Web 2.0 technologies
• Mashups
• Google Earth and kml
• XQuery and eXist

3
Being an Early Adopter

• Learning new technologies when
• No official textbooks
• No definitive documentation
• You need to get ahead of the game
• Use
• Examples
• Discussion groups
• Application Programmer interfaces
• Reading page sources
• Digging and delving
• Experimenting with small examples, smaller
  changes to larger examples
• Keep a lab book (or a blog) of results and
  lessons learnt

4
Web 2.0

• Key ideas
• Sharing information (blogs, wikis, RSS, ICQ/IM,
  social book-marking)
• Information reuse (mashups, tagging
• A couple of Key Technologies
• Hosted applications (Basecamp, Campfire,
  Stikipad)
• Mapping
• XML

5
Individual TaskStart a blog

• http//www.blogger.com/start
• The blog will be submitted for evaluation
• Exercise results should be entered into the blog,
  with discussion
• Later you can edit the spreadsheet of all blogs
  with your name and blog address

6
Wiki

• http//cems.stikipad.com/web2
• This wiki has been developed to provide an
  overview of Web 2.0 stuff for this class and
  another running next year.
• Task (during the day)
• Add a new page to the wiki and link it in to the
  appropriate place. Document this and reference
  the new page in your blog

7
Mashups

• Combining information from multiple sources
• Application gets data from a source
• Page-scraping (parsing HTML)
• Application Programmer Interface (API)
• SOAP / REST /JavaScript functions
• RSS (Real Simple Syndication)
• E.g.
• housing

8
TASK (in Pairs)

• Browse through ProgrammeableWeb and select a
  mash-up of interest.
• http//www.programmableweb.com/
• Questions to answer and document in your blog
• What sources of information are being used?
• How is the data obtained technically?
• How are the sources combined
• How useful is this mashup?
• What questions does it raise?

9
Google Earth

• Google Earth is a client-side application (needs
  a download) so not used in this list of Mashups
• Location-based browsing will be a big thing

10
Google Earth Demo

• StudentsOnline
• Google Earth operations
• Creating Folders
• Creating Placemarks
• Editing Location and Description
• Editing Icons
• Saving as kml
• Partner Organisations map

11
Google Earth Task (pairs)

• Decide on a trip (last holiday), place (home
  town), news event for the pair to document using
  GE, or the CEMS partner map
• Create an overlay
• 20 minutes only can finish in your own time!
• Save as kml

12
Understanding kml

• Experimental
• Use a text editor (Notepad, PFE32) to load the
  text file, change a description, save and reload
  (after deleting the original)
• Use Word 2003 to load the file what doesit tell
  you about the file?
• Online documentation the Google Earth
  specification
• Draw a tree diagram to explain the general
  structure

13
Understanding Latitude and Longitude
1 minute of longitude goes to zero at the poles
Bristol
1 minute of latitude 1 Nautical Mile
1.150779 miles
51 27 19.08 N 2 35 30.76 W
-2
-1
0
Lines of equal latitude
50
60 seconds in 1 minute 60 minutes in 1 degree 360
degrees in a full circle
Lines of equal longitude
0 latitude is the Equator
,
, -
(0, 0) of the West coast of Africa
GE Reference system is WGS84
0 longitude is the Greenwich Meridian
14
Geocoding

• To determine the latitude and longitude of an
  address or postcode
• US zipcodes geocoded
• UK Postcodes
• commercially available in bulk
• Individual geocoding in Google Earth, Google Map
• ? Other countries.

15
Advanced Google Earth

• Icons
• Style can be designed
• For each Placemark
• For a set of placemarks by creating a style with
  an id
• Small icons can be selected from the big pallette
  pngs each is 32 32 pixels, arranged in 8 rows
  of 8, numbered 0- 7 from the bottom-left.
• Specific icons can be selected with the
  appropriate x, y, h, w parameters

16
XML

• Well-formed
• Tags nested, attributes quoted, single root
• Self-describing
• So you can guess at the meaning of each item of
  data
• Terms
• Root
• Element
• Attribute
• Child and Parent
• Typed values and CDATA
• Draw a diagram (however you like) to show the
  general structure of a kml file
• Review the structures

17
Using an XML database

• kml is just text, so any scripting programme can
  generate it (PHP, ASP JSP etc)
• kml is XML so any XML tools can process it
• an XML database
• Stores XML documents (and other things)
• Provides an XQuery interpreter to query the
  documents and to generate new documents.

18
Exist database

• Exist http//exist-db.org/
• Working System Students Online
• My links http//www.cems.uwe.ac.uk/cjwallac/NXD/
  index.htm
• Student server http//studentexistdb.cems.uwe.ac.u
  k8080/exist/index.xml
• Sandbox interface for executing simple queries
• Admin interface for browsing collections
• JavaStart interface for adding resources, XML
  files and XQuery files to the database

19
XPath

• A language for selecting nodes in a tree
  structure - Trees

20
XQuery

• Michael Kayss 10 minute tutorial
• Exist is similar cant set the context node in
  the Sandbox, but only one file like this so
  queries should still work (ignore any leading .)
• Go on the FLOWR tutorial

21
XQueries in EXist

• You can store XQueries in Exist
• Save to a text file
• Using the webstart client, ad them to your user
  area
• Execute them by using the admin interface to
  locate the script and running it.

22
Added functions

• XQuery Functions
• See w3schools
• http//www.w3schools.com/xpath/xpath_functions.asp
  
• String functions
• Exist functions
• See eXist functions
• http//demo.exist-db.org/xquery/functions.xq
• Input HTTP request parameters

23
Example

• Trip spreadsheet
• Trip2kml.xql

24
Final task

• Your task in pairs is to choose a news story for
  Google news
• Find using Google or a geocoder the location of
  places relevant to the story
• The class will agree a common format for geocoded
  news stories
• Adapt the XML spreadsheet to hold the data you
  need about the story
• Adapt the trip2kml XQuery to convert your story
  into a kml file
• Collect all the stories into one collection
• Create a query to find all the news stories about
  places within N miles of a given location