def renders(col_name):
def wrap(f):<EOL><INDENT>if not hasattr(f, '<STR_LIT>'):<EOL><INDENT>f._col_name = col_name<EOL><DEDENT>return f<EOL><DEDENT>return wrap<EOL>
Use this decorator to map your custom Model properties to actual
Model db properties. As an example::

    class MyModel(Model):
        id = Column(Integer, primary_key=True)
        name = Column(String(50), unique = True, nullable=False)
        custom = Column(Integer(20))

        @renders('custom')
        def my_custom(self):
            # will render this columns as bold on ListWidget
            return Markup('<b>' + custom + '</b>')

    class MyModelView(ModelView):
        datamodel = SQLAInterface(MyTable)
        list_columns = ['name', 'my_custom']