[mapserver-dev] mapscript styleObj and colorObj

[Seth G]

Hi all,

A general mapscript question I'm hoping someone can provide some information on. 
Should any attribute that is a C class be read-only in SWIG, and requires getters/setters to update?

For example the styleObj attributes [1] includes a color property that is of type colorObj. This can be set in MapScript, but I believe this causes undefined behaviour, and any property that is not a basic int/str/float type will need a setter function added in the SWIG interface files. 

For example the following Python script runs without crashing, however when output back to a Mapfile contains strange results:

    import mapscript

    style = mapscript.styleObj()

    style.updateFromString("""
    STYLE
        COLOR  1 2 3
    END # STYLE
    """)

    success = style.color.setRGB(100, 150, 200)
    # the following asserts all pass
    assert success == mapscript.MS_SUCCESS

    assert style.color.red == 100
    assert style.color.green == 150
    assert style.color.blue == 200
    assert style.color.alpha == 255

    print(style.convertToString())


Outputs the following:

STYLE
  COLOR 200 255 3
END # STYLE

Note the blue value has become red, the alpha green, and I don't know where the 3 comes from. 

I'm guessing the setter function for the styleObj color needs to be added?

Seth

[1] https://mapserver.org/mapscript/mapscript.html#styleobj-attributes

--
web:http://geographika.co.uk
twitter: @geographika