[gdal-dev] OGR Feature Style Specification

[Tamas Szekeres]

2008/4/17, Ari Jolma <ari.jolma at tkk.fi>:

>  Since SVG is a pretty general it should be able to handle all styles and
> mapping to it is then just a technical problem?
>

I don't know

>
> > 5. How about the compatibility issues with the existing applications?
> > Would it be easy to migrate their existing scripts. For example if the
> > application use the WHERE OGR_STYLE LIKE 'BRUSH' according to
> > http://www.gdal.org/rfc6_sqlgeom.html ?
> >
> >
>
>  That kind of statement assumes quite much and I'm not sure if such
> constraints should be encouraged. There is no "brush" in SVG styles AFAIK.
> Maybe SVG styles should be implemented as a "new styles" and deprecate the
> old styles eventually?
>

One of the use cases I'm aware of is when a mapinfo layer contains
features with different styles and we would like to distinguish
between those features. For example if I want to select all of the
labels from that layer and represent the labels as a separate layer in
mapserver.

>
> > Further issues:
> >
> > 6. Can we support the dataset/layer level default styles as described
> > in the OGR Feature Style specification but haven't been implemented
> > yet?
> >
> >
>
>  Isn't that the matter of just adding a style member into the dataset/layer
> class? Do features have knowledge of the layer they belong to? Then they can
> return the default style if they do not have a style of their own.
>

The features don't have back references to their layers at the moment.

Tamas