style: add Styles.default()

Steve Canny · Steve Canny · commit 99aeee40cc6b · 2015-02-08T00:01:14.000-08:00
diff --git a/docx/oxml/parts/styles.py b/docx/oxml/parts/styles.py
@@ -5,7 +5,7 @@
 """
 
 from ...enum.style import WD_STYLE_TYPE
-from ..simpletypes import ST_String
+from ..simpletypes import ST_OnOff, ST_String
 from ..xmlchemy import (
     BaseOxmlElement, OptionalAttribute, ZeroOrMore, ZeroOrOne
 )
@@ -26,6 +26,7 @@ class CT_Style(BaseOxmlElement):
     pPr = ZeroOrOne('w:pPr', successors=_tag_seq[17:])
     type = OptionalAttribute('w:type', WD_STYLE_TYPE)
     styleId = OptionalAttribute('w:styleId', ST_String)
+    default = OptionalAttribute('w:default', ST_OnOff)
     del _tag_seq
 
     @property
@@ -53,6 +54,19 @@ class CT_Styles(BaseOxmlElement):
     """
     style = ZeroOrMore('w:style', successors=())
 
+    def default_for(self, style_type):
+        """
+        Return `w:style[@w:type="*{style_type}*][-1]` or |None| if not found.
+        """
+        default_styles_for_type = [
+            s for s in self._iter_styles()
+            if s.type == style_type and s.default
+        ]
+        if not default_styles_for_type:
+            return None
+        # spec calls for last default in document order
+        return default_styles_for_type[-1]
+
     def get_by_id(self, styleId):
         """
         Return the ``<w:style>`` child element having ``styleId`` attribute
@@ -74,3 +88,9 @@ def get_by_name(self, name):
             return self.xpath(xpath)[0]
         except IndexError:
             return None
+
+    def _iter_styles(self):
+        """
+        Generate each of the `w:style` child elements in document order.
+        """
+        return (style for style in self.xpath('w:style'))
diff --git a/docx/styles/styles.py b/docx/styles/styles.py
@@ -43,7 +43,10 @@ def default(self, style_type):
         Return the default style for *style_type* or |None| if no default is
         defined for that type (not common).
         """
-        raise NotImplementedError
+        style = self._element.default_for(style_type)
+        if style is None:
+            return None
+        return StyleFactory(style)
 
     def get_by_id(self, style_id, style_type):
         """
diff --git a/features/par-style-prop.feature b/features/par-style-prop.feature
@@ -4,7 +4,6 @@ Feature: Each paragraph has a read/write style
   I need the ability to get and set the style of a paragraph
 
 
-  @wip
   Scenario Outline: Get the style of a paragraph
      Given a paragraph having <style> style
       Then paragraph.style is <expected-value>
diff --git a/tests/styles/test_styles.py b/tests/styles/test_styles.py
@@ -50,6 +50,15 @@ def it_raises_on_style_not_found(self, get_raises_fixture):
         with pytest.raises(KeyError):
             styles[key]
 
+    def it_can_get_the_default_style_for_a_type(self, default_fixture):
+        styles, style_type, StyleFactory_ = default_fixture[:3]
+        StyleFactory_calls, style_ = default_fixture[3:]
+
+        style = styles.default(style_type)
+
+        assert StyleFactory_.call_args_list == StyleFactory_calls
+        assert style is style_
+
     def it_can_get_a_style_of_type_by_id(self, get_by_id_fixture):
         styles, style_id, style_type = get_by_id_fixture[:3]
         default_calls, _get_by_id_calls, style_ = get_by_id_fixture[3:]
@@ -72,6 +81,27 @@ def it_gets_a_style_by_id_to_help(self, _get_by_id_fixture):
 
     # fixture --------------------------------------------------------
 
+    @pytest.fixture(params=[
+        ('w:styles',
+         False, WD_STYLE_TYPE.CHARACTER),
+        ('w:styles/w:style{w:type=paragraph,w:default=1}',
+         True, WD_STYLE_TYPE.PARAGRAPH),
+        ('w:styles/(w:style{w:type=table,w:default=1},w:style{w:type=table,w'
+         ':default=1})',
+         True, WD_STYLE_TYPE.TABLE),
+    ])
+    def default_fixture(self, request, StyleFactory_, style_):
+        styles_cxml, is_defined, style_type = request.param
+        styles_elm = element(styles_cxml)
+        styles = Styles(styles_elm)
+        StyleFactory_calls = [call(styles_elm[-1])] if is_defined else []
+        StyleFactory_.return_value = style_
+        expected_value = style_ if is_defined else None
+        return (
+            styles, style_type, StyleFactory_, StyleFactory_calls,
+            expected_value
+        )
+
     @pytest.fixture(params=[None, 'Foo'])
     def get_by_id_fixture(self, request, default_, _get_by_id_, style_):
         style_id, style_type = request.param, 1
