doc: add DocumentPart.get_style_id()

Steve Canny · Steve Canny · commit 2d909ca53789 · 2015-02-08T00:01:15.000-08:00
diff --git a/docx/parts/document.py b/docx/parts/document.py
@@ -82,7 +82,7 @@ def get_style_id(self, style_or_name, style_type):
         if *style_or_name* is a style of the wrong type or names a style not
         present in the document.
         """
-        raise NotImplementedError
+        return self.styles.get_style_id(style_or_name, style_type)
 
     @lazyproperty
     def inline_shapes(self):
diff --git a/docx/styles/styles.py b/docx/styles/styles.py
@@ -58,6 +58,17 @@ def get_by_id(self, style_id, style_type):
             return self.default(style_type)
         return self._get_by_id(style_id, style_type)
 
+    def get_style_id(self, style_or_name, style_type):
+        """
+        Return the id of the style corresponding to *style_or_name*, or
+        |None| if *style_or_name* is |None|. If *style_or_name* is not
+        a style object, the style is looked up using *style_or_name* as
+        a style name, raising |ValueError| if no style with that name is
+        defined. Raises |ValueError| if the target style is not of
+        *style_type*.
+        """
+        raise NotImplementedError
+
     def _get_by_id(self, style_id, style_type):
         """
         Return the style of *style_type* matching *style_id*. Returns the
diff --git a/tests/parts/test_document.py b/tests/parts/test_document.py
@@ -114,6 +114,17 @@ def it_can_get_a_style_by_id(self, get_style_fixture):
         )
         assert style is style_
 
+    def it_can_get_the_id_of_a_style(self, get_style_id_fixture):
+        document_part, style_or_name, style_type, style_id_ = (
+            get_style_id_fixture
+        )
+        style_id = document_part.get_style_id(style_or_name, style_type)
+
+        document_part.styles.get_style_id.assert_called_once_with(
+            style_or_name, style_type
+        )
+        assert style_id is style_id_
+
     def it_provides_access_to_its_styles_part_to_help(
             self, styles_part_get_fixture):
         document_part, styles_part_ = styles_part_get_fixture
@@ -171,6 +182,13 @@ def get_style_fixture(self, styles_prop_, style_):
         styles_prop_.return_value.get_by_id.return_value = style_
         return document_part, style_id, style_type, style_
 
+    @pytest.fixture
+    def get_style_id_fixture(self, styles_prop_):
+        document_part = DocumentPart(None, None, None, None)
+        style_or_name, style_type, style_id_ = 'Foo Bar', 1, 'FooBar'
+        styles_prop_.return_value.get_style_id.return_value = style_id_
+        return document_part, style_or_name, style_type, style_id_
+
     @pytest.fixture
     def inline_shapes_fixture(self, request, InlineShapes_):
         document_elm = (
