WMS server time tests and issues

[Yewondwossen Assefa]

Kralidis,Tom [Burlington] wrote:

>>-----Original Message-----
>>From: Yewondwossen Assefa [mailto:assefa at dmsolutions.ca]
>>Sent: Monday, 08 November, 2004 16:00
>>To: Kralidis,Tom [Burlington]
>>Cc: MAPSERVER-DEV at LISTS.UMN.EDU
>>Subject: Re: [UMN_MAPSERVER-DEV] WMS server time tests and issues
>>
>>
>>Kralidis,Tom [Burlington] wrote:
>>
>>>Hi,
>>>
>>>I've been testing this out on latest CVS.  Observations:
>>>
>>>- OS: FC2
>>>Linux devgeo.cciw.ca 2.6.5-1.358smp #1 SMP Sat May 8
>>
>>09:25:36 EDT 2004
>>
>>>i686 i686 i386 GNU/Linux
>>>- httpd: Apache 2.0.49
>>>
>>>I constructed a dummy .shp/.shx/.dbf with 4 columns 3
>>
>>records with a
>>
>>>timefield.
>>>
>>>Here's a dump of what the shapefile is:
>>>
>>>stid | lat          | lon        | obsdate
>>>----------------------------------------------
>>>tom  | 45.412766    | -71.920082 | 2004-10-12
>>>bob  | 45.399400    | -75.704200 | 2003-09-30
>>>joe  | 55.399400    | -95.704200 | 2002-03-17
>>>
>>>
>>>...and here's the time defines in LAYER/METADATA in mapfile:
>>>
>>>   "wms_timeextent" "2002-03-17/2004-10-12"
>>>   "wms_timedefault" "2003-09-30"
>>>   "wms_timeitem" "obsdate"
>>>
>>>
>>>...and here's my tests:
>>>
>>>Single value:
>>>
>>>
>>
>>http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&
>>
>>>re
>>>
>>
>>quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transpa
>>rent=TRUE&
>>
>>exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,2
>
> 8.606653,-
>
>>51.243500,81.998653&width=500&height=300&time=2004-10-12-T00:0
>>0:00&style
>>
>>>s=default
>>>
>>>Result: no problem, as expected
>>>
>>>Multple value:
>>>
>>>
>>
>>http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&
>>
>>>re
>>>
>>
>>quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transpa
>>rent=TRUE&
>>
>>exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,2
>
> 8.606653,-
>
>>51.243500,81.998653&width=500&height=300&time=2004-10-12-T00:0
>>0:00,2003-
>>
>>>09-30-T00:00:00&styles=default
>>>
>>>Result: no problem, as expected
>>>
>>>Single range:
>>>
>>>
>>
>>http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&
>>
>>>re
>>>
>>
>>quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transpa
>>rent=TRUE&
>>
>>exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,2
>
> 8.606653,-
>
>>51.243500,81.998653&width=500&height=300&time=2002-03-17-T00:0
>>0:00/2004-
>>
>>>10-12-T00:00:00&styles=default
>>>
>>>
>>>Result: when the start time or end time is out of range of the
>>>default. For example, if you change the start year to 2001,
>>
>>only one
>>
>>>point shows
>>>up:
>>>
>>>
>>
>>http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&
>>
>>>re
>>>
>>
>>quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transpa
>>rent=TRUE&
>>
>>exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,2
>
> 8.606653,-
>
>>51.243500,81.998653&width=500&height=300&time=2001-03-17-T00:0
>>0:00/2004-
>>
>>>10-12-T00:00:00&styles=default
>>>
>>>...so it looks like the default is returned when the range given is
>>>outside the range defined in "wms_timeextent".
>>>
>>>Is this the expected behaviour?  As a WMS client, I would
>>
>>expect that
>>
>>>temporal queries would return everything inside two given
>>
>>dates, just
>>
>>>like a spatial query does.
>>>
>>>..Tom
>>>
>>>
>>
>>I think that the specs indicates that if the given values are
>>"incorrect" the server would return values for the default declared :
>>
>>Section C5.1 (Annexe C wms 1.1.1 ):
>>" ...An OGC Web Service may declare a default for any dimension. A
>>'default' is optional but recommended. If a request does not
>>include a
>>value along this dimension, and a default has been declared, then the
>>server shall send the default value..."
>>
>>  The implementation was the interpretation of this text.
>>
>
>
> Thanks for the clarification -- being a spec zealot I should have read
> up on this!!
>
> At any rate, if I comment out "wms_timedefault", and I specify:
>
> http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&re
> quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transparent=TRUE&
> exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,28.606653,-
> 51.243500,81.998653&width=500&height=300&time=2002-03-17-T00:00:00/2004-
> 10-12-T00:00:00&styles=default
>
> ...it works as expected.  If I specify a range outside the time extents,
> i.e.:
>
> http://devgeo.cciw.ca/cgi-bin/mapserv/ecows?version=1.1.1&service=WMS&re
> quest=GetMap&layers=obs&format=image/gif&srs=EPSG:4326&transparent=TRUE&
> exceptions=application%2Fvnd.ogc.se_inimage&bbox=-140.243500,28.606653,-
> 51.243500,81.998653&width=500&height=300&time=2001-03-17-T00:00:00/2004-
> 10-12-T00:00:00&styles=default
>
> I get prompted to download image/tiff.  What happens in this case?
>

It should normally send an exception of this nature :

<?xml version='1.0' encoding="ISO-8859-1" standalone="no" ?>
<!DOCTYPE ServiceExceptionReport SYSTEM
"http://ogc.dmsolutions.ca/wms/1.1.1/exception_1_1_1.dtd">
<ServiceExceptionReport version="1.1.1">
<ServiceException code="InvalidDimensionValue">
msWMSApplyTime: WMS server error. Time value(s) 2003-01-01 14:10 given
is invalid or outside the time extent defined (2004-01-01/2004-02-01).
</ServiceException>
</ServiceExceptionReport>

Not sure where the image/tiff comes from.

Later,

--
----------------------------------------------------------------
Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
----------------------------------------------------------------