2013/Hollywood/Persistent Location Tracking

People

• http://aaronparecki.com
• Code

  https://github.com/esripdx/Offline-Logger-iOS

  This app logs locations and step counts from an iOS 7 device, and sends it periodically via a POST request to a URL you define.

  A simple backend for this should accomplish the following:

  • Store the location and timestamp (and any other associated values like accuracy and speed)
  • Query by timestamp
  • Query by date range
  • Query by location
  • Location data should be returned with: latitude, longitude, timezone, locality, region and country

  Looking up the timezone for a location is relatively easy. See the timezone example of Terraformer for a Node.js implementation, and a PHP implementation.

  Unfortunately, building a reverse geocoder to convert latitude/longitude to a city/state/country is not trivial. It is definitely possible to run your own service for this. See OpenStreeMap's Nominatim. There are also a number of services available for doing reverse geocode queries, all with slightly different TOS and pricing.

  • http://www.factual.com/products/geopulse-context
  • http://www.mapquestapi.com/geocoding/#reverse
  • http://geocoder.ca/?premium_api=1
  • http://resources.arcgis.com/en/help/arcgis-rest-api/index.html#//02r30000000n000000
  • http://blog.programmableweb.com/2012/06/21/7-free-geocoding-apis-google-bing-yahoo-and-mapquest/

  
  

  Authentication

  Currently only token-based authentication is possible by including a token in the config URL. rknLA is working on adding HMAC auth to the app so that if there is a secret provided in the setup URL, it will sign the requests so it can be verified on the server without requiring HTTPS.

  Pull request adding HMAC support: https://github.com/esripdx/Offline-Logger-iOS/pull/2

  See Also

  • 2013/Hollywood