style: add LatentStyles.__getitem__()

Author: Steve Canny

docx/oxml/styles.py

@@ -38,6 +38,16 @@ class CT_LatentStyles(BaseOxmlElement):
     """
     lsdException = ZeroOrMore('w:lsdException', successors=())
 
+    def get_by_name(self, name):
+        """
+        Return the `w:lsdException` child having *name*, or |None| if not
+        found.
+        """
+        found = self.xpath('w:lsdException[@w:name="%s"]' % name)
+        if not found:
+            return None
+        return found[0]
+
 
 class CT_Style(BaseOxmlElement):
     """

docx/styles/latent.py

@@ -20,6 +20,15 @@ class LatentStyles(ElementProxy):
 
     __slots__ = ()
 
+    def __getitem__(self, key):
+        """
+        Enables dictionary-style access to a latent style by name.
+        """
+        lsdException = self._element.get_by_name(key)
+        if lsdException is None:
+            raise KeyError("no latent style with name '%s'" % key)
+        return _LatentStyle(lsdException)
+
     def __iter__(self):
         return (_LatentStyle(ls) for ls in self._element.lsdException_lst)
 

features/sty-access-latent-styles.feature

@@ -10,7 +10,6 @@ Feature: Access latent styles for a document
       And len(latent_styles) is 137
 
 
-  @wip
   Scenario: Access latent style in collection
      Given a latent style collection
       Then I can iterate over the latent styles

tests/styles/test_latent.py

@@ -28,8 +28,37 @@ def it_can_iterate_over_its_latent_styles(self, iter_fixture):
         for latent_style in lst:
             assert isinstance(latent_style, _LatentStyle)
 
+    def it_can_get_a_latent_style_by_name(self, getitem_fixture):
+        latent_styles, name, lsdException = getitem_fixture
+        latent_style = latent_styles[name]
+        assert isinstance(latent_style, _LatentStyle)
+        assert latent_style._element is lsdException
+
+    def it_raises_on_latent_style_not_found(self, getitem_raises_fixture):
+        latent_styles, name = getitem_raises_fixture
+        with pytest.raises(KeyError):
+            latent_styles[name]
+
     # fixture --------------------------------------------------------
 
+    @pytest.fixture(params=[
+        ('w:lsdException{w:name=Ab},w:lsdException,w:lsdException', 'Ab', 0),
+        ('w:lsdException,w:lsdException{w:name=Cd},w:lsdException', 'Cd', 1),
+        ('w:lsdException,w:lsdException,w:lsdException{w:name=Ef}', 'Ef', 2),
+    ])
+    def getitem_fixture(self, request):
+        cxml, name, idx = request.param
+        latentStyles_cxml = 'w:latentStyles/(%s)' % cxml
+        latentStyles = element(latentStyles_cxml)
+        lsdException = latentStyles[idx]
+        latent_styles = LatentStyles(latentStyles)
+        return latent_styles, name, lsdException
+
+    @pytest.fixture
+    def getitem_raises_fixture(self):
+        latent_styles = LatentStyles(element('w:latentStyles'))
+        return latent_styles, 'Foobar'
+
     @pytest.fixture(params=[
         ('w:latentStyles',                                  0),
         ('w:latentStyles/w:lsdException',                   1),