[Mapserver-dev] Re: time support

Paul Spencer spencer at dmsolutions.ca
Tue Dec 16 21:54:44 EST 2003

if I could add a couple of cents ...

would it be possible to provide a TIMEINDEXFORMAT as well?  By this, I 
mean that not everyone is going to have there time stored in the same 
way.  The TIMEINDEXFORMAT could be used to convert the time from its 
internal storage (as defined by the source data) to an internal 
representation that could be used much more easily to evalutate 
expressions.  I think that this would allow for more intelligent time 
based support, although it may cause things to run more slowly I guess.



Daniel Morissette wrote:
> (I decided to move this to mapserver-dev)
> Steve Lime wrote:
>> Do you mean TILEINDEX or the new TIMEINDEX? I could certainly see doing
>> filtering on the TIMEINDEX, especially as applied to non-raster data.
>> Using filters on tiles could certainly be done but would there be any
>> real practical use for the output. The new TIMEINDEX is accomanied by a
>> TIMEID, and the TIMEID could be interpreted as a MapServer expression so
>> you could process mutiple files at one time. 
> I didn't know about the name of the new TIMEINDEX so I really meant 
> My idea was simply that instead of creating a new TIMEINDEX we could 
> simply extend the existing TILEINDEX to support filter expressions. The 
> expression could be based on time or on any other attribute in the 
> tileindex file.
> We would also need to extend the expressions stuff in MapServer to 
> support time comparisons and time ranges. That would be a generic 
> enhancement to the expression stuff and could be class EXPRESSIONs and 
> not just in the layer FILTER.
> Does it make more sense? I'm scared I'm not expressing myself very well...
>> That would be more work to
>> add than simply interpreting TIMEID as a single value.
> I actually thought that extending the TILEINDEX to support FILTER would 
> be simpler.  Would it not just be a matter of adding a call to 
> msEvalExpression() in the code that scans the tile index?
> Daniel

|Paul Spencer                           spencer at dmsolutions.ca    |
|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|

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