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

• Seth Girvin @geographika