Proposed change to symbols.

[Jason Maestri]

Hey, while we're discussing symbols... As nearly as I can tell, there is no way to query mapserver for the symbol for a specific layer/class (for use in legends, and elsewhere),  is that something is possible, and if not, could it be made possible (Steve)?

--Jason

imap at chesapeake.net wrote:

> Steve/List,
>
> Being one of the advocates for symbol/marker changes, here is some rationale
> behind the changes.  The current symbol files are somewhat static and if the
> files become large, there is overhead incurred on every invocation of mapserv.
> Also, the current scheme also does not lend itself to dynamic marker placement
> very
> well.  (that is, using a marker NOT defined in marker.sym)
>
> We want to be able to use external markers from a PATH filespec to make it
> easier
> to maintain (no more editing the marker.sym file ;) and (2) make it more
> programmer
> friendly and simplifies the mapscript a bit.
>
> As far as functionality, it would be nice to interrogate a $class->{symbol} to
> determine it's height/width and some sort of option to set/get control of
> collision
> avoidance (labelcache).  (I think needed for both POINT and ANNOTATION
> layers) And lastly, make sure to preserve the ability to examine to labelcache
> to
> extract the polygons of the markers and text placed on the map.
>
> I am all for getting rid of marker.sym 100% although it may break my current
> applications...  sometimes change is painful.   Anyway to code an interim
> solutions that works both ways?  probably not, but thought I would ask anyway.
>
> Regards,
>
> Chris Stuber (mapsurfer)
> Silicon Mapping Solutions, Inc.
> 410.257.3187
>
> Stephen Lime wrote:
> >
> > I'd like to propose a couple of changes to the way symbols are handled. This is to make symbols easier to manage and to support some additional functionality proposed by a couple of other users. The initial change would be this:
> >
> > Do away with separate marker, line and shade symbol files in favor of a single symbol file. Also, allow symbol definitions in the map file.
> >
> > Syntax would be the same and access (i.e. symbols referenced in class objects) would be the same. These changes allow for a simpler MapScript symbol interface and additional opportunities for defining symbols on-the-fly. Begining in 3.3.011 you can already specify a GIF/PNG file (relative to the location of the map file) in a class object (i.e. SYMBOL "graphics/marker.gif") and a symbol is dynamically created. MapScript method $map->getSymbolByName("graphics/marker.gif"); will also work.
> >
> > Any thoughts or can I code it?
> >
> > Steve