mappyfile-colors

A mappyfile plugin to standardise and convert colors used in a Mapfile. Features include:

conversion between RGB and HEX colors
harmonise all colors in a Mapfile to either RGB or hex values
add human readable color names as comments
add color names to RGB color ranges as comments (not currently possible for HEX color ranges)

See example.map and rainbow_classes.txt for the Mapfile to generate the above image.

Installation

pip install mappyfile-colors

Note installing the mappyfile-colors plugin will automatically install the following dependencies:

mappyfile
webcolors

Online Demo

Go to the MapServer Studio at https://app.mapserverstudio.net/
Open the "Rainbow colors" map (File > Open > Rainbow)
Open "Settings", the Color Formatting section allows conversion to RGB and HEX, and to include color names as comments in the Mapfile output
Click the Format button

Usage

To use the colors plugin, import, and then pass in a custom ColorsTransformer. Two additional parameters can also be passed to the mappyfile.loads function:

include_color_names - set to True to add color names as comments (default is False)
conversion_type - a parameter to convert colors within a Mapfile, either import ConversionType or use an integer value to set the conversion:
```
NO_CONVERSION = 0
TO_RGB = 1
TO_HEX = 2
```

A sample script to convert RGB to HEX colors, and include the color names is shown below.

import mappyfile
from mappyfile.plugins import mappyfile_colors
from mappyfile_colors import ColorsTransformer, ConversionType

s = """
CLASS
    STYLE
        COLOR 184 134 11
        OUTLINECOLOR 0 0 255
        WIDTH 3
    END
END
"""

d = mappyfile.loads(s, include_color_names=True, transformer_class=ColorsTransformer, conversion_type=ConversionType.TO_HEX)
print(mappyfile.dumps(d))

This will output the following:

CLASS
    STYLE
        COLOR "#b8860b" # darkgoldenrod
        OUTLINECOLOR "#0000ff" # blue
        WIDTH 3
    END
END

See the test_plugin.py for further examples.

Color Factory

The plugin also includes a ColorFactory class to return unique colors from color palettes. This can be useful for generating MapServer classes based on unique values. Basic usage is shown below:

color_factory = mappyfile_colors.ColorFactory()
print(color_factory.palette_names)
clrs = color_factory.get_colors(palette_name="maximum_contrast")  # returns an iterator
print(next(clrs))

Author