While location-based mobile apps are becoming increasingly popular, they are still relatively new. Special considerations need to be made for battery life and handling large data sets of geolocated data. The good news is there are many services and technologies you can use to assist you in building mobile location-based apps. In this session, Aaron Parecki, co-founder of Geoloqi.com, shows you services you can leverage to do things like nearby business lookups, location-based triggers, nearest intersection queries, and more. Aaron also covers the location services available on the various mobile platforms as well as in HTML 5, and shares some insights on how to deal with battery life. The session concludes with some real-world use cases for real-time location such as turning on and off your lights in your house or sending an SMS when you leave work.

1. Geolocation in
Web and Mobile Apps
Aaron Parecki – Web Directions – May 2011
aaron@parecki.com – http://aaron.pk – @aaronpk
Slides and code available at
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2. Displaying a Map
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3. Displaying a Map - HTML
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4. Displaying a Map - iPhone
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5. Displaying a Map - Android
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6. Finding the User’s
Location
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7. Browser Geolocation
! Desktop browsers use nearby wifi hotspots
! Mobile devices may use GPS or cell tower positioning
! You can also use IP lookups to get a rough location
(but is usually very inaccurate)
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8. Browser
Geolocation
with Wifi
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9. Browser Geolocation
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10. Browser Geolocation
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11. Finding the User’s Location
using Javascript
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12. Browser Geolocation
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13. Browser Geolocation
! Usability problem with this approach:
! User is left with an empty page waiting for them to press
“allow”
! You should do the best you can with no location, and then
update your page after you get the user’s location
! Could use IP-based location to center a map somewhere that
is (probably) nearby
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14. Using SimpleGeo
Start with IP-based geolocation to quickly center the map.
Update with browser-based geolocation after it’s available.
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15. Finding Nearby Businesses
! SimpleGeo Places
! Foursquare API
! Twitter API
! Yelp API
! Google Places API
! Many others
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16. Place Search with Foursquare
developer.foursquare.com
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17. Place Search with SimpleGeo
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18. Place Search with SimpleGeo
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19. Finding Information
About a Location
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20. SimpleGeo Context
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21. SimpleGeo Context
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22. Monitoring Continuous
Location
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23. Monitoring Continuous
Location in Javascript
Now go run around outside!
(But keep the browser open)
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24. Keep the browser open? That’s kind of lame.
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25. Monitoring Continuous
Location on the iPhone
This will keep running in the background!
(But now you will potentially drain the battery)
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26. Saving battery by
Getting the User’s
Approximate Location
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27. Retrieving Approximate
Location on the iPhone
[locationManager startMonitoringSignificantLocationChanges];
• Your app will be re-launched in the background
when the user moves “significantly”
• Most likely when they change cell towers
• Location is very rough, ~500-1500m accuracy
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28. Retrieving Approximate
Location on Android
locationManager.requestLocationUpdate(
LocationManager.PASSIVE_PROVIDER, 0, 0, listener);
• Service runs in the background, gets locations
when other providers or apps request location.
• Could be cell tower location, could be GPS
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29. Location-Based Triggers
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30. Geonotes Try it! aaron.pk/geonote
Location-Based Reminders
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31. Trigger-Based
Actions
Create triggers
based on where
users are.
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32. Send a message to all users
within a radius.
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33. Arrived
Notify X when you arrive at place Y
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34. Real-time location-based gaming
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35. mapattack.org
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36. Hybrid Web/Native App
Web Views
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37. Communicating Between the
Web and Native Components
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38. Communicating Between the
Web and Native Components
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39. Turning On/Off Your Lights
Geoloqi
API
Your
Home
Server
X10
SMSified.com
Your
Home
And sending an SMS when you leave work Lights
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40. X10 Lamp
Switch
Linux Command Line X10 Client
www.heyu.org
$ heyu on A1
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41. @aaronpk aaron.pk/unplugged11

42. Create a Layer in Geoloqi
Docs: geoloqi.org/API/layer/create
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43. Create a Trigger in Geoloqi
Docs: geoloqi.org/API/trigger/create
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44. Handling a Trigger from Geoloqi
Docs: geoloqi.org/Trigger_Callback
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45. Create an SMS Number
smsified.com
or
tropo.com
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46. Send an SMS
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47. Questions?
Code: aaron.pk/unplugged11
Geoloqi API: geoloqi.org/API
SMS API: smsified.com
Aaron Parecki @aaronpk
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