Problems translating map file layers to mapscript

[Sean Gillies]

Comments inline ...

On Oct 18, 2005, at 11:21 AM, Damon Butler wrote:

>> # Should I have to set these? Can they be made tranparent?
>
> Yes. And Yes.
>
>> #c.label.backgroundcolor = mapscript.colorObj(255, 255, 255)
>> #c.label.outlinecolor = mapscript.colorObj(255, 255, 255)
>
> They can be made transparent by supplying negative numbers for the R, 
> G,
> and B values.
>
> c.label.backgroundcolor = mapscript.colorObj(-1, -1, -1)
> c.label.outlinecolor = mapscript.colorObj(-1, -1, -1)
>

Never done must this be! Proper usage is

     c.label.backgroundcolor.setRGB(-1, -1, -1)
     c.label.outlinecolor.setRGB(-1, -1, -1)

Otherwise the previously defined colors will be dereferenced improperly 
and never cleaned up by Python's garbage collector. Anyhow, these 
attributes begin with default values (-1, -1, -1), so no need to alter 
them if you want the no-background default.

> But I'm afraid that I don't have any insights into your other queries
> (repeated below).
>
> --Damon
>
>> I'm also having to specify c.label.minsize and c.label.maxsize,
>> otherwise the labels come out just one or two pixels tall. It's like
>> there are some defaults that are assumed in the map file but that need
>> to be made explicit in the mapscript version.
>>
>> Any insights appreciated,
>>

No, the defaults are fine with mapscript. If you have turned on auto 
label scaling, then you will need to set minsize and maxsize. 
Otherwise, class.label.size controls all.

>> --David Niergarth
>>
>> P.S. I wonder if anyone has ever written a code generator that could
>> translate map file fragments (like a layer) to mapscript API calls? 
>> I'm
>> discovering doing it by hand is pretty tedious.

David, define all this boilerplate in a mapfile, and then modify that 
configuration with mapscript:

     m = mapscript.mapObj('template.map')
     l = m.getLayer(0)
     l.status = mapscript.MS_ON
     l.name = 'activated layer'
     ...

cheers,
Sean

--
Sean Gillies
sgillies at frii dot com
http://zcologia.com