Location Based Services and Geo-tagging.Geo2tag platform
introduction.
Agenda
Architecture overview
Installation process
Source code overview
JSON interface
Client librarieshttp_requests
Jgeo
Qt example
Android example
Location Based Services
LBS = using geographical contextIndoor services
Mobile healthcare
City informationTransport
Traffic
...
Geo-tagging
Def: the process of adding geographical identification metadata
to various media:Photo, video
Web-pages,
SMS, QR-codes
files
Terminology
Tag tuple ,t time
B,L,H coordinates
data text data ~1K
Channel classifier for group of tags
Main features of tagging system
Access to tags
Classification
Filtering
Session and User management
Massive data processing
Features
CurrentBasic geo-tagging
Plain and spacial filtration
Load balancing across Databases and web servers
Will be published in 2013Exporters (wikimapia, google maps, OSM,
4square)
Channel aggregation
Multi-service databases
Installation (test system)
Visit http://build64.geo2tag.org/
Add line to /etc/apt/sources.listdeb http://build64.geo2tag.org/
geo2tag main
Install packagessudo apt-get update
sudo apt-get install reinstall geo2tag
Check installationhttp:///service/version
http:///service/build
Channels and tags
LBS Platform Channel
ChannelChannelChannel
Tag- time- coordinates- data (link)
Filtration- time- radius- figure (2D or 3D)
TagTag
Tag
Geo2tag architecture
Query engineSession managerHP
database
BLOBscacheIndexerCluster/cloudinfrastructurebackend
clients
Libraries: jgeo, http_reqsSession
cachewebandroidwebQt-basedembedded
JSON
System cache
Resources
Main site http://geo2tag.org
Tracker https://geo2tag.atlassian.net/
Sources https://github.com/OSLL/geo2tag
Support: [email protected]
CI server: pulse.geo2tag.org
JSON/REST API
Command:Service URL
Function
Parameters
Examplehttp://debug.geo2tag.org/service?{json}Json:
'{"login":"User","password":"pwd@"}
RESTful API
REST = Representational State Transfer 2000 by Roy Fielding
The model of http (v 1.0)
HTTP POST is being used for communication.
Goals of REST
Scalability of component interactions
Generality of interfaces
Independent deployment of components
encapsulate legacy systems
Java script Object Notation
Text-based, Object-oriented, data interchange format.
Structure:A collection of name/value pairs
Ordered list of values.
Grammar
Begin-array [ left square bracket
Begin-object { left curly bracket
End-array ] right square bracket
End-object } right curly bracket
Name-separator : colon
Value-separator ; , comma
Examples
{ "Image": { "Width": 800, "Height": 600, "Title": "View from
15th Floor", "Thumbnail": { "Url":
"http://www.example.com/image/481989943", "Height": 125, "Width":
"100" }, "IDs": [116, 943, 234, 38793]}
Geo2tag REST API
Based on JSON objects interchange
Command:URIService URL
Function
Parameters: JSON object
ExampleURI http://debug.geo2tag.org/service/loginParams (Json):
'{"login":"User","password":"test"}
Session token
clientserver
/version
{errno: 0, version : 1.02}
/login {login : user, password:pwd}
{errno: 0, auth_token : 765888876588}
/loadTags {auth_token : 765888876588,
latitude:23.0, longitude:12.0, radius: 5}
{errno: 0, ...}
Invoking by curl
$ curl -d '{"login":"User","password":"test"}'
http://debug.geo2tag.org/service/login
Live example(curl)
Command security
Plain commands (version, build,...)
Session managementlogin
closeSession
Authorized commandsWith session token
Session workflow
Check version
Acquire session token
R/W tags, channels
Close session
Login
/loginlogin
password
User management
/addUserlogin
password
Email
/deleteUserlogin
Channel Management
/addChannelname
description
url
radius
/owned
/subscribe
/subscribed
Working with tags
/writeTagchannel
description
{coordinates}
time
title
/loadTagslatitude
longitude
radius
Qt interface(http_requests)
Qt interface(demo application)
java interface(jgeo)
Practice: Android
Demo: LoginActivity
Demo: RequestSender
Demo: login()
Demo: Chat Activity
Demo: Activity Transition
Demo: Location Updating
Demo: availableChannels()
Demo: subscribeChannel()
Demo: Channel chooser
Demo: writeTag()
Demo: loadTags()
Demo: TagsView updating
Demo: background updating
Practice: Qt
Contacts
[email protected]
Petrozavodsk, Apr 2013
Click to edit the title text format
