add a test (currently fails) to test object introspection down to symbolizer level once objects have been placed in the map

tests/python_tests/introspection_test.py

@@ -0,0 +1,60 @@
+#!/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 for now...
+    assert isinstance(p2,mapnik.PointSymbolizer)
+    
+    eq_(p2.allow_overlap, True)
+    eq_(p2.opacity, 0.5)
+    eq_(p2.filename,'../data/images/dummy.png')