[mapserver-users] dynamic class creation vs. static

[Pushkar Pradhan]

Data organiz.:
city_bounds.shp
One of the Attributes is Place_name
I know I can use a criteria like POPULATION > 50K and POPULATION <= 50K
I hope the client's specs. were like this but he has specified particular
city names,
rivers.shp: some random rivers to be drawn. Moreover all these must be
done in different colors, e.g. each river in new color.
Thus I defined each city he wants in the .map file as a diff. class, but
the COLOR values etc. I set them in mapscript.
I hope that's a reasonable approach?

P.S.: The data that the client wants displayed is just random not based on
any criteria.
> Pushkar,
>
> Off hand is seems like you are approaching the problem from the wrong
> direction, IE there is a different way to solve the problem. Only I'm
> having trouble understanding how you data is organized.
>
> For example, if I want to display cities I have a cities.shp file that
> has the point locations of the cities and the name as an attribute. Then
> I make a layer to display and label the cities. If I want different
> symbols for say population then I set a a CLASS ITEM "POPULATION" and
> set up CLASSes with EXPRESSIONs to display different symbols or circle
> sizes based on the expression.
>
> So what does your data look like and what do you wnat to do with it.
> Clearly as you posted you don't want to declare 30 some classes.
>
> -Steve
>
> Pushkar Pradhan wrote:
> >
> > I have a list of layers (~30 or more), I need to display only certain
> > classes in each of these. There doesn't seem to be a criteria defined by
> > my client, just a word file containing the names.
> >
> > Static:
> > Pasting the names of the classes in each layer in the .map file seems
> > boring, i.e. in cities layer he wants 30 cities to be displayed.
> > LAYER cities
> >
> > CLASS1
> > CLASS2
> > ...
> > CLASS30
> >
> > END
> >
> > similarly for all layers
> >
> > Dynamic:
> > I can take the layer name and look it up in a text file which contains the
> > city names and then create all the classes in a loop:
> > for(no. of cities in the text file) {
> >    create new class obj.
> >    set attributes
> > }
> >
> > Would the 1st approach be faster, I think in the 2nd approach the classes
> > will be created each time a user zooms in or adds more classes, please
> > advice. Thanks,
> >
> > -Pushkar S. Pradhan
>

-Pushkar S. Pradhan