4D Raster access NOT via WMS?

[Samuel Hiatt]

Can anyone help with this last question?  I'm hesitant to start hacking at
this 'cause I don't really feel like re-inventing the wheel... again.  Is
anyone familiar with the mechanism that is used when mapserver gets a WMS
request with a TIME parameter?  Maybe the solution lies there.

The metadata tags required to make 4D WMS layers work all have "wms_ ..." at
the beginning.  I imagine that extending this functionality to any type of
mapserver request (WMS, mapscript, CGI) would be very valuable (if it
doesn't exist already).

Thanks for your help.

Sam




On 10/12/07, Samuel Hiatt <samhiatt at gmail.com> wrote:
>
> Thanks for the help.
>
> It should be very easy to filter my files for time.  What should my
> mapfile look like for the 4D layer?  The same thing as for a 4D wms layer,
> with the tile index and wms_* metadata tags but I would use mapscript to
> screen the files?  Do you know of a way I might reuse the screening code
> that is used for 4D WMS?
>
> Thanks!
> Sam
>
>
>
> On 10/12/07, Yewondwossen Assefa <assefa at dmsolutions.ca> wrote:
> >
> > Samuel Hiatt wrote:
> > > Hi!  Thanks for the reply.
> > >
> > > So I suppose when I make a WMS request with TIME Mapserver applies the
> > > filter behind the scenes, finding which feature in my tile_index.shp
> > > represents the correct time and then processes the raster pointed to
> > by
> > > that feature?  So if I want to implement the same kind of thing with
> > > mapscript I'd have to write the filter myself?
> > >
> >   That is correct : assuming that the underlying data can be filtered
> > using a time field, you need to know the attribute and build the time
> > expression and set it using mapscript.
> >
> > > The reason I am interested in doing this is to extend temporal
> > > functionality to ka-map.  I may end up abandoning that approach and
> > > moving to a javascript WMS client (like OpenLayers of MapBuilder)
> > instead.
> > >
> > > Thanks for your help.
> > >
> > > Sam
> > >
> > >
> > >
> > > On 10/11/07, *Yewondwossen Assefa* <assefa at dmsolutions.ca
> > > <mailto:assefa at dmsolutions.ca>> wrote:
> > >
> > >     Hi there,
> > >
> > >       The Time parameter that is sent with a WMS request is simply
> > >     converted
> > >     to a time expression and set on the filter object of the layer. In
> > the
> > >     case of wms. the metadata wms_timeitem will be used for the
> > >     attribute name.
> > >       if you are using mapscript, you would need to build the time
> > >     expression manually and set the filter parameter. Please refer to
> > >     http://mapserver.gis.umn.edu/docs/howto/wms_time_support (section
> > 2.5)
> > >     to see how time parameters are interpreted.
> > >
> > >     Best Regards,
> > >
> > >
> > >     Samuel Hiatt wrote:
> > >      > I am excited to see that Mapserver supports 4D raster layers
> > for WMS,
> > >      > but I am curious if this functionality can be extended to
> > mapscript
> > >      > calls as well?  For example, if I set up a raster layer with a
> > TIME
> > >      > dimension then will it be possible for me to request an image
> > for a
> > >      > specific time with mapscript?  Or would I have to do this with
> > a
> > >     WMS call?
> > >      >
> > >      > Thanks!
> > >      >
> > >      > Sam
> > >
> > >
> > >     --
> > >     ----------------------------------------------------------------
> > >     Assefa Yewondwossen
> > >     Software Analyst
> > >
> > >     Email: assefa at dmsolutions.ca <mailto:assefa at dmsolutions.ca>
> > >     http://www.dmsolutions.ca/
> > >
> > >     Phone: (613) 565-5056 (ext 14)
> > >     Fax:   (613) 565-0925
> > >     ----------------------------------------------------------------
> > >
> > >
> >
> >
> > --
> > ----------------------------------------------------------------
> > Assefa Yewondwossen
> > Software Analyst
> >
> > Email: assefa at dmsolutions.ca
> > http://www.dmsolutions.ca/
> >
> > Phone: (613) 565-5056 (ext 14)
> > Fax:   (613) 565-0925
> > ----------------------------------------------------------------
> >
> >
>
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