[mapserver-users] combine objects (was Rosa and CGI)

[Richard Greenwood]

At 01:26 PM 5/14/2002 -0400, you wrote:
>Could a feature join be done in mapscript? Theoretically I believe yes,
>because the nature of a shape is more like a region than it is a polygon. 
>However
>I have not tried combining two "in" shapeObjects into a single "out"
>shapeObj.

You lost me there - what is an "in" and an "out" object?

>A step back may be required at this point to see if joinning the
>shapes will cause more of a problem then it is worth. For example: if you
>have two parcel polygons that both share a common parcel identifier but do
>NOT share a common acreage you can not combine the individual polygons
>into a single "shape" without loosing one of the distinct acreages or
>combining the two acreages together before assigning the new acreage
>value. If the CGI version does require a single record you may want to
>look at using mapscript to handle the many-to-one or many-to-many
>relationships.

Yes, good point. I am always struggling with the one-to-many relationship 
problems associated with parcel mapping. With the CGI version of mapserver, 
I found it necessary to aggregate multi-polygon parcels into single objects 
so that if I queried for a parcel I only got one object back to map. e.g. 
If I have a multi-polygon parcel X and did an itemquery on X (like an 
address look up), I got back each polygon as a separate map (not what I 
wanted), so I aggregated all my multi-polygon parcels into single objects 
and got the results I wanted from itemquery: a single object in a single 
map. In my case it was more important to be able to show all of the 
multi-polygon parcel in one map than to carry attribute data for the 
individual polygons.

And I agree with you that the best way might be to use mapscript, unless 
someone can show me how to highlite multiple objects in one itemquery map.

Best regards,
Rich


Richard W. Greenwood, PLS
Greenwood Mapping, Inc.
Rich at GreenwoodMap.com
(307) 733-0203
http://www.GreenwoodMap.com