style: add Document.styles_part

Steve Canny · Steve Canny · commit f1ca7b469374 · 2014-02-02T21:15:41.000-08:00
diff --git a/docx/api.py b/docx/api.py
@@ -14,6 +14,7 @@
 from docx.opc.constants import CONTENT_TYPE as CT, RELATIONSHIP_TYPE as RT
 from docx.package import Package
 from docx.parts.numbering import NumberingPart
+from docx.parts.styles import StylesPart
 from docx.shared import lazyproperty
 
 
@@ -146,6 +147,19 @@ def save(self, path_or_stream):
         """
         self._package.save(path_or_stream)
 
+    @lazyproperty
+    def styles_part(self):
+        """
+        Instance of |StylesPart| for this document. Creates an empty styles
+        part if one is not present.
+        """
+        try:
+            return self._document_part.part_related_by(RT.STYLES)
+        except KeyError:
+            styles_part = StylesPart.new()
+            self._document_part.relate_to(styles_part, RT.STYLES)
+            return styles_part
+
     @property
     def tables(self):
         """
diff --git a/docx/parts/styles.py b/docx/parts/styles.py
@@ -0,0 +1,25 @@
+# encoding: utf-8
+
+"""
+Provides StylesPart and related objects
+"""
+
+from __future__ import (
+    absolute_import, division, print_function, unicode_literals
+)
+
+from ..opc.package import Part
+
+
+class StylesPart(Part):
+    """
+    Proxy for the styles.xml part containing style definitions for a document
+    or glossary.
+    """
+    @classmethod
+    def new(cls):
+        """
+        Return newly created empty styles part, containing only the root
+        ``<w:styles>`` element.
+        """
+        raise NotImplementedError
diff --git a/tests/test_api.py b/tests/test_api.py
@@ -16,6 +16,7 @@
 from docx.package import Package
 from docx.parts.document import DocumentPart, InlineShapes
 from docx.parts.numbering import NumberingPart
+from docx.parts.styles import StylesPart
 from docx.table import Table
 from docx.text import Paragraph, Run
 
@@ -142,6 +143,24 @@ def it_creates_numbering_part_on_first_access_if_not_present(
         )
         assert numbering_part is numbering_part_
 
+    def it_provides_access_to_the_styles_part(self, styles_part_get_fixture):
+        document, document_part_, styles_part_ = styles_part_get_fixture
+        styles_part = document.styles_part
+        document_part_.part_related_by.assert_called_once_with(RT.STYLES)
+        assert styles_part is styles_part_
+
+    def it_creates_styles_part_on_first_access_if_not_present(
+            self, styles_part_create_fixture):
+        document, StylesPart_, document_part_, styles_part_ = (
+            styles_part_create_fixture
+        )
+        styles_part = document.styles_part
+        StylesPart_.new.assert_called_once_with()
+        document_part_.relate_to.assert_called_once_with(
+            styles_part_, RT.STYLES
+        )
+        assert styles_part is styles_part_
+
     # fixtures -------------------------------------------------------
 
     @pytest.fixture(params=[0, 1, 2, 5, 9])
@@ -307,6 +326,27 @@ def save_fixture(self, request, open_, package_):
         document = Document()
         return document, package_, file_
 
+    @pytest.fixture
+    def StylesPart_(self, request, styles_part_):
+        StylesPart_ = class_mock(request, 'docx.api.StylesPart')
+        StylesPart_.new.return_value = styles_part_
+        return StylesPart_
+
+    @pytest.fixture
+    def styles_part_(self, request):
+        return instance_mock(request, StylesPart)
+
+    @pytest.fixture
+    def styles_part_create_fixture(
+            self, document, StylesPart_, document_part_, styles_part_):
+        document_part_.part_related_by.side_effect = KeyError
+        return document, StylesPart_, document_part_, styles_part_
+
+    @pytest.fixture
+    def styles_part_get_fixture(self, document, document_part_, styles_part_):
+        document_part_.part_related_by.return_value = styles_part_
+        return document, document_part_, styles_part_
+
     @pytest.fixture
     def table_(self, request):
         return instance_mock(request, Table, style=None)
