Added the ability to specify any set of characters as the "bullet con…

…tent"

like it is supported by ReportLab.

src/z3c/rml/attr.py

@@ -122,6 +122,14 @@ def __init__(self, value_types=(), *args, **kw):
         super(Combination, self).__init__(*args, **kw)
         self.value_types = value_types
 
+    @property
+    def element(self):
+        return self.context.element
+
+    @property
+    def parent(self):
+        return self.context.parent
+
     def fromUnicode(self, value):
         for value_type in self.value_types:
             bound = value_type.bind(self)

src/z3c/rml/stylesheet.py

@@ -627,8 +627,14 @@ class IBaseListStyle(IMinimalListStyle):
     start = attr.Combination(
         title=u'Start Value',
         description=u'The counter start value.',
-        value_types=(attr.Integer(),
-                     attr.Choice(choices=interfaces.UNORDERED_BULLET_VALUES)),
+        value_types=(
+            # Numeric start value.
+            attr.Integer(),
+            # Bullet types.
+            attr.Choice(choices=interfaces.UNORDERED_BULLET_VALUES),
+            # Arbitrary text.
+            attr.String(),
+            ),
         required=False)