On Mon, Aug 23, 2010 at 2:45 PM, Johan Ekblad <jka@ekblad.org> wrote:
2010-08-23 14:10, Tom Van Braeckel skrev:
I'm going on my honeymoon in a few days and I could use the offline
logging capabilities to avoid roaming data costs.
That's why I'm starting on the issue about offline logging capabilities
<https://sourceforge.net/apps/trac/opengeotracker/ticket/10>, for the
benefit of everyone :-)


Thanks :-) The marriage is this Fryday at 15h CEST.

Suggestions about the implementation are more than welcome, here are a
few thoughts:

Server side:
- As discussed in the trac issue, we will use logMany.php

Client side:
- the client should be able to log at least one month of data, suppose
that's 259 200 datapoints (6/minute) or maybe ~100Mb of data
- I suggest logging the data to a human readable text file on the SD
card, so the user can see what's being logged,
- the client should check the HTTP return code of logMany.php, and
re-POST if for some reason the HTTP POST failed (connection lost,...)

Any more hints, tips, tricks ?
Feel free !


Last release we also introduced logging of altitude, speed, bearing, accuracy, provider and time. Maybe we should allow to cache in two modes:

1) Cache all data
2) Just cache latitude, longitude and time (maybe also altitude)

If we save in clear text-format, using the CSV-format, we get (maybe all decimals arn't needed)


(thats 69 chars per row including CR) => 17 884 800 bytes, not too much. Maybe we can save everything the phone logs.

My phone currently logs this:


No maybe we should log everything that's available (there's not so much difference)

My thoughts exactly - storage is pretty cheap so I don't think too much data will be an issue. If it turns out the log file is getting too big, we can always extend the code to allow logging less.

Okay, plain text CSV format it is. I'll dive right in and start coding.


Met vriendelijke groeten, Salutations sincères, Kind regards,

Tom Van Braeckel
GSM: 0032 (0) 486 63 58 04

Btw, I'm working on a map-implementation with html5 and google maps api v3 (we are currently using v2). I have currently marked all locations with "moose-towers" for the moose hunting season, that starts in September. 

Of cause I will rewrite a new version of our showPos.php when I'm ready. You can have a look at:


Cool, that sounds promising ! I'm happy to see you're such an active user. And thanks for sharing too - who knows, I might someday be in Sweden and interested in hunting moose :-)


 //regards: Johan