HiLiting / selecting multiple features

[Xin]

Hi Steve,

Thanks for the response.  It's always good to know there's someone out there
that can help!

Here's our situation.  We use MapServer CGI wrapped in a C# application.
The app would call MapServer with various CGI parameters depending on what
the user is doing in the application.

One functionality we need is to hilite features on a map and for it to
return results of features from other layers intersecting it.  The return
results party is working great.

A single feature can be hilited at the moment using mode=featurenquery,
slayer, and passing img.x and img.y.  For example, this might be a building
parameter.  This works to a degree.  We haven't been able to control the
colour correctly with QUERYMAP and COLOR.  But that's another issue.

Hiliting multiple features is what we are after.  We would like our users to
be able to click on a feature on the map through our application.  Then we
would hilite this through MapServer.  Then the user can click on more
features.  We'd like the initial feature, and any features clicked on after
to be all hilighted.  e.g. user clicks on three building parameters.

The problem we are facing is hiliting multiple features.  Do you have any
suggestions on how we may do this?

Xin

On 13/04/06, Steve Lime <Steve.Lime at dnr.state.mn.us> wrote:
>
> Xin: There's a big difference between a feature and a shape though. The
> imgshape parameter was intended for use with something really simple
> like a DHTML digitizer so at this point it only supports a single feature.
> It
> would not be hard to hack mapserv.c to allow mulitple instances of
> imgshape to build up a more complex feature (holes, multiple outer rings).
>
> I'm not sure if that's what you need though. There are other ways to
> highlight features. Perhaps you could describe the steps in which the
> application is used along with desired outputs. That would make it easier
> to suggest alternatives.
>
> Steve
>
> >>> Xin <crazygecko at GMAIL.COM> 4/13/2006 4:51:47 AM >>>
> We are user MapServer cgi to hilite features the user select on.  This is
> done by using mode=featurequery and slayer.  We need to selectemultiple
> features, and have them hilighted.  Having looked at the docs, there
> doesn't
> seem to be any obvious ways of doing this.
>
> One possible solution is to use IMGSHAPE and nquery.  This is documented
> as:
>
> Shape given in image coordinates.
>
> An arbitrary polygon shape to be used for query purposes. Multiple
> instances
> simply add parts to the shape so it is possible to construct a shape with
> holes. Used with modes NQUERY and NQUERYMAP.
> But using imgshape would require one than one polygon being passed
> through.
> Rick asked this in March without getting a response.  Is it possible to
> pass
> multiple polygons using imgshape?
>
> Any other suggestions are more than welcome.
>
> Cheers,
> Xin
>
>
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