mapnik/tests/python_tests/introspection_test.py

#!/usr/bin/env python

from nose.tools import *
from utilities import Todo

import mapnik

def test_introspect_symbolizers():
    # create a symbolizer
    p = mapnik.PointSymbolizer("../data/images/dummy.png", "png", 16, 16)
    p.allow_overlap = True
    p.opacity = 0.5
    
    eq_(p.allow_overlap, True)
    eq_(p.opacity, 0.5)
    eq_(p.filename,'../data/images/dummy.png')
     
    # make sure the defaults
    # are what we think they are
    eq_(p.allow_overlap, True)
    eq_(p.opacity,0.5)
    eq_(p.filename,'../data/images/dummy.png')
    
    # contruct objects to hold it
    r = mapnik.Rule()
    r.symbols.append(p)
    s = mapnik.Style()
    s.rules.append(r)
    m = mapnik.Map(0,0)
    m.append_style('s',s)

    # try to figure out what is
    # in the map and make sure
    # style is there and the same
        
    s2 = m.find_style('s')
    rules = s2.rules
    eq_(len(rules),1)
    r2 = rules[0]
    syms = r2.symbols
    eq_(len(syms),1)
    
    ## TODO here, we can do...
    sym = syms[0]
    # this is hackish at best
    p2 = sym.symbol()
    assert isinstance(p2,mapnik.PointSymbolizer)

    eq_(p2.allow_overlap, True)
    eq_(p2.opacity, 0.5)
    eq_(p2.filename,'../data/images/dummy.png')
        
    ## but we need to be able to do:
    p2 = syms[0] # get the actual symbolizer, not the variant object
    # this will throw ...
    raise Todo('need to expose symbolizer instances')
    assert isinstance(p2,mapnik.PointSymbolizer)
    
    eq_(p2.allow_overlap, True)
    eq_(p2.opacity, 0.5)
    eq_(p2.filename,'../data/images/dummy.png')