Feat: Add Alt text properties and setters

pptx/oxml/shapes/shared.py

@@ -167,6 +167,17 @@ def shape_name(self):
         """
         return self._nvXxPr.cNvPr.name
 
+    @property
+    def shape_alt_text(self):
+        """
+        Alt text of this shape
+        """
+        return self._nvXxPr.cNvPr.descr
+
+    @shape_alt_text.setter
+    def shape_alt_text(self, value):
+        self._nvXxPr.cNvPr.descr = value
+
     @property
     def txBody(self):
         """
@@ -304,6 +315,7 @@ class CT_NonVisualDrawingProps(BaseOxmlElement):
     hlinkHover = ZeroOrOne("a:hlinkHover", successors=_tag_seq[2:])
     id = RequiredAttribute("id", ST_DrawingElementId)
     name = RequiredAttribute("name", XsdString)
+    descr = OptionalAttribute('descr', XsdString)
     del _tag_seq
 
 

pptx/shapes/base.py

@@ -132,6 +132,17 @@ def name(self):
     def name(self, value):
         self._element._nvXxPr.cNvPr.name = value
 
+    @property
+    def alt_text(self):
+        """
+        Alternative text for the shape
+        """
+        return self._element.shape_alt_text
+
+    @alt_text.setter
+    def alt_text(self, value):
+        self._element.shape_alt_text = value
+
     @property
     def part(self):
         """The package part containing this shape.

tests/shapes/test_base.py

@@ -57,6 +57,15 @@ def it_can_change_its_name(self, name_set_fixture):
         shape.name = new_value
         assert shape._element.xml == expected_xml
 
+    def it_knows_its_alt_text(self, alt_text_fixture):
+        shape, expected_value = alt_text_fixture
+        assert shape.alt_text == expected_value
+
+    def it_can_change_its_alt_text(self, alt_text_set_fixture):
+        shape, new_value, expected_xml = alt_text_set_fixture
+        shape.alt_text = new_value
+        assert shape._element.xml == expected_xml
+
     def it_has_a_position(self, position_get_fixture):
         shape, expected_left, expected_top = position_get_fixture
         assert shape.left == expected_left
@@ -255,6 +264,29 @@ def name_set_fixture(self, request):
         expected_xml = xml(expected_xSp_cxml)
         return shape, new_value, expected_xml
 
+    @pytest.fixture
+    def alt_text_fixture(self):
+        shape_elm = element("p:sp/p:nvSpPr/p:cNvPr{id=1,name=foo,descr=foo}")
+        shape = BaseShape(shape_elm, None)
+        return shape, 'foo'
+
+    @pytest.fixture(
+        params=[
+            (
+                "p:sp/p:nvSpPr/p:cNvPr{id=1,name=foo,descr=foo}",
+                Shape,
+                "bar",
+                "p:sp/p:nvSpPr/p:cNvPr{id=1,name=foo,descr=bar}",
+            )
+        ]
+    )
+    def alt_text_set_fixture(self, request):
+        xSp_cxml, ShapeCls, new_value, expected_xSp_cxml = request.param
+        shape = ShapeCls(element(xSp_cxml), None)
+        expected_xml = xml(expected_xSp_cxml)
+        expected_xml = xml(expected_xSp_cxml)
+        return shape, new_value, expected_xml
+
     @pytest.fixture
     def part_fixture(self, shapes_):
         parent_ = shapes_