style: add Styles.get_by_id()

Steve Canny · Steve Canny · commit a9024643acd6 · 2015-02-08T00:01:14.000-08:00
diff --git a/docx/styles/styles.py b/docx/styles/styles.py
@@ -38,12 +38,29 @@ def __iter__(self):
     def __len__(self):
         return len(self._element.style_lst)
 
+    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
+
     def get_by_id(self, style_id, style_type):
         """
         Return the style of *style_type* matching *style_id*. Returns the
         default for *style_type* if *style_id* is not found or is |None|, or
         if the style having *style_id* is not of *style_type*.
         """
+        if style_id is None:
+            return self.default(style_type)
+        return self._get_by_id(style_id, style_type)
+
+    def _get_by_id(self, style_id, style_type):
+        """
+        Return the style of *style_type* matching *style_id*. Returns the
+        default for *style_type* if *style_id* is not found or if the style
+        having *style_id* is not of *style_type*.
+        """
         raise NotImplementedError
 
     @staticmethod
diff --git a/tests/styles/test_styles.py b/tests/styles/test_styles.py
@@ -14,7 +14,7 @@
 from docx.styles.styles import Styles
 
 from ..unitutil.cxml import element
-from ..unitutil.mock import call, function_mock, instance_mock
+from ..unitutil.mock import call, function_mock, instance_mock, method_mock
 
 
 class DescribeStyles(object):
@@ -34,13 +34,13 @@ def it_can_iterate_over_its_styles(self, iter_fixture):
         assert count == expected_count
         assert StyleFactory_.call_args_list == expected_calls
 
-    def it_can_get_a_style_by_id(self, get_by_id_fixture):
-        styles, key, expected_element = get_by_id_fixture
+    def it_can_get_a_style_by_id(self, getitem_id_fixture):
+        styles, key, expected_element = getitem_id_fixture
         style = styles[key]
         assert style._element is expected_element
 
-    def it_can_get_a_style_by_name(self, get_by_name_fixture):
-        styles, key, expected_element = get_by_name_fixture
+    def it_can_get_a_style_by_name(self, getitem_name_fixture):
+        styles, key, expected_element = getitem_name_fixture
         style = styles[key]
         assert style._element is expected_element
 
@@ -49,14 +49,36 @@ def it_raises_on_style_not_found(self, get_raises_fixture):
         with pytest.raises(KeyError):
             styles[key]
 
+    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:]
+        style = styles.get_by_id(style_id, style_type)
+        assert styles.default.call_args_list == default_calls
+        assert styles._get_by_id.call_args_list == _get_by_id_calls
+        assert style is style_
+
     # fixture --------------------------------------------------------
 
+    @pytest.fixture(params=[None, 'Foo'])
+    def get_by_id_fixture(self, request, default_, _get_by_id_, style_):
+        style_id, style_type = request.param, 1
+        styles = Styles(None)
+        default_calls = [call(style_type)] if style_id is None else []
+        _get_by_id_calls = (
+            [] if style_id is None else [call(style_id, style_type)]
+        )
+        default_.return_value = _get_by_id_.return_value = style_
+        return (
+            styles, style_id, style_type, default_calls, _get_by_id_calls,
+            style_
+        )
+
     @pytest.fixture(params=[
         ('w:styles/(w:style{%s,w:styleId=Foobar},w:style,w:style)', 0),
         ('w:styles/(w:style,w:style{%s,w:styleId=Foobar},w:style)', 1),
         ('w:styles/(w:style,w:style,w:style{%s,w:styleId=Foobar})', 2),
     ])
-    def get_by_id_fixture(self, request):
+    def getitem_id_fixture(self, request):
         styles_cxml_tmpl, style_idx = request.param
         styles_cxml = styles_cxml_tmpl % 'w:type=paragraph'
         styles = Styles(element(styles_cxml))
@@ -68,7 +90,7 @@ def get_by_id_fixture(self, request):
         ('w:styles/(w:style,w:style%s/w:name{w:val=foo})', 'foo',       1),
         ('w:styles/w:style%s/w:name{w:val=heading 1}',     'Heading 1', 0),
     ])
-    def get_by_name_fixture(self, request):
+    def getitem_name_fixture(self, request):
         styles_cxml_tmpl, key, style_idx = request.param
         styles_cxml = styles_cxml_tmpl % '{w:type=character}'
         styles = Styles(element(styles_cxml))
@@ -111,6 +133,14 @@ def len_fixture(self, request):
 
     # fixture components ---------------------------------------------
 
+    @pytest.fixture
+    def default_(self, request):
+        return method_mock(request, Styles, 'default')
+
+    @pytest.fixture
+    def _get_by_id_(self, request):
+        return method_mock(request, Styles, '_get_by_id')
+
     @pytest.fixture
     def style_(self, request):
         return instance_mock(request, BaseStyle)
