cascadenik 2.6.5

Cascading Stylesheets For Mapnik

Cascadenik
==========

Cascadenik implements cascading stylesheets for Mapnik.

It’s an abstraction layer and preprocessor that converts special, CSS-like
syntax into Mapnik-compatible style definitions. It’s easier to write complex
style rules using the alternative syntax, because it allows for separation of
symbolizers and provides a mechanism for inheritance.

Cascadenik supports many of Mapnik’s features in a simple declarative form:

/* Define a few colors */
@black: #000;
@orange: #f90;

/* Start with a white background */
Map
{
map-bgcolor: #fff;
}

/* Draw roads as orange lines */
#roads
{
/* Usually, 3px wide */
line-width: 3;
line-color: @orange;

/* Make the important ones wider */
&[kind=major] { line-width: 4 }
&[kind=highway] { line-width: 5 }

/* Add the road names in black */
name
{
text-placement: line;
text-face-name: "DejaVu Sans Book";
text-fill: @black;
text-size: 12;
}
}

See more examples at https://github.com/mapnik/Cascadenik/wiki/Examples.

Usage
-----

See `INSTALL.md` for installation instructions.

See the `doc/` folder for more usage examples.

Unroll the rules in example.mss and show their cascade order:

% cascadenik-style.py example.mss > example-ordered-unrolled.mss

Compile `example.mml` into a Mapnik-suitable XML file:

% cascadenik-compile.py example.mml example-compiled.xml

Render a MML file directly to an image using nik2img.py:

% nik2img.py example.mml example.png