Class element

The class element defines a feature class. Feature classes break down a dataset into categories, based on a filter query, that you can treat or style separately.

Usage

You can use a feature class to fetch a subset of features:

    <model ...>
        <features name="world" driver="ogr">
            ...
        </features>

        <!-- Only render countries that are members of NATO: -->
        <class name="class1">
            <query>
                <expr> nato="true" </expr>
            </query>
            <style type="text/css">
                 world { fill: #66ff66; }
            </style>
        </class>
    </model>

Or, you can use several feature classes to render different feature in different ways. Please refer to the <style> page for an example.