oxml: add CT_P.style setter

Steve Canny · Steve Canny · commit 77be8c945d16 · 2013-12-20T21:05:12.000-08:00
diff --git a/docx/oxml/text.py b/docx/oxml/text.py
@@ -21,6 +21,17 @@ class CT_P(OxmlBaseElement):
     """
     ``<w:p>`` element, containing the properties and text for a paragraph.
     """
+    def __setattr__(self, attr, value):
+        """
+        Implement setter side of properties. Filters ``__setattr__`` messages
+        to ObjectifiedElement base class to intercept messages intended for
+        custom property setters.
+        """
+        if attr == 'style':
+            self._set_style(value)
+        else:
+            super(CT_P, self).__setattr__(attr, value)
+
     def add_r(self):
         """
         Return a newly added CT_R (<w:r>) element.
@@ -53,7 +64,35 @@ def style(self):
         String contained in w:val attribute of <w:pPr><w:pStyle> child, or
         None if that element is not present.
         """
-        return self.pPr.style if hasattr(self, 'pPr') else None
+        return self.pPr.style if self._has_pPr else None
+
+    def _get_or_add_pPr(self):
+        """
+        Return the pPr child element of this <w:p> element, adding a new one
+        if one is not present.
+        """
+        if not self._has_pPr:
+            self.insert(0, CT_PPr.new())
+        return self.pPr
+
+    @property
+    def _has_pPr(self):
+        """
+        Return True if this <w:p> element has a <w:pPr> child element, False
+        otherwise.
+        """
+        return hasattr(self, 'pPr')
+
+    def _set_style(self, style):
+        """
+        Set style of this <w:p> element to *style*. If *style* is None,
+        remove the style element. If the pPr element is empty after the
+        operation, remove it.
+        """
+        pPr = self._get_or_add_pPr()
+        pPr.style = style
+        if pPr.countchildren() == 0:
+            self.remove(pPr)
 
 
 class CT_PPr(OxmlBaseElement):
diff --git a/features/paragraph_style.feature b/features/paragraph_style.feature
@@ -3,7 +3,6 @@ Feature: Each paragraph has a read/write style
   As an python-docx developer
   I need to get and set the style of a paragraph
 
-  @wip
   Scenario: Set the style of a paragraph
      Given a new document created from the default template
       When I add a new paragraph to the body
diff --git a/tests/oxml/test_text.py b/tests/oxml/test_text.py
@@ -47,6 +47,26 @@ def it_knows_its_paragraph_style(self):
             p = builder.with_nsdecls().element
             assert p.style == expected_value
 
+    def it_can_set_its_paragraph_style(self):
+        # effectively an integration test with CT_PPr
+        pPr = a_pPr().with_style('foobar')
+        pPr2 = a_pPr().with_style('barfoo')
+        cases = (
+            (1, a_p(), None, a_p()),
+            (2, a_p(), 'foobar', a_p().with_pPr(pPr)),
+            (3, a_p().with_pPr(pPr), None, a_p()),
+            (4, a_p().with_pPr(pPr), 'barfoo', a_p().with_pPr(pPr2)),
+        )
+        for case_nmbr, before_bldr, new_style, after_bldr in cases:
+            print before_bldr.with_nsdecls().xml
+            print 'case_nmbr, new_style => %d, %s' % (case_nmbr, new_style)
+            p = before_bldr.with_nsdecls().element
+            p.style = new_style
+            expected_xml = after_bldr.with_nsdecls().xml
+            print expected_xml
+            print p.xml
+            assert p.xml == expected_xml
+
 
 class DescribeCT_PPr(object):
 
