Updated ElementBase._setSubText and added unit tests.

_setSubText can now handle elements specified by an XPath expression, and
will build up the element tree as needed, reusing an existing elements in
the path.

sleekxmpp/xmlstream/stanzabase.py

@@ -374,6 +374,49 @@ class ElementBase(object):
       else:
           return stanza.text
 
+    def _setSubText(self, name, text=None, keep=False):
+        """
+        Set the text contents of a sub element.
+
+        In case the element does not exist, a element will be created,
+        and its text contents will be set.
+
+        If the text is set to an empty string, or None, then the 
+        element will be removed, unless keep is set to True.
+
+        Arguments:
+            name -- The name or XPath expression of the element.
+            text -- The new textual content of the element. If the text
+                    is an empty string or None, the element will be removed
+                    unless the parameter keep is True.
+            keep -- Indicates if the element should be kept if its text is
+                    removed. Defaults to False.
+        """
+        name = self._fix_ns(name)
+        element = self.xml.find(name)
+
+        if not text and not keep:
+            return self.__delitem__(name)
+
+        if element is None:
+            # We need to add the element. If the provided name was
+            # an XPath expression, some of the intermediate elements
+            # may already exist. If so, we want to use those instead
+            # of generating new elements.
+            last_xml = self.xml
+            walked = []
+            for ename in name.split('/'):
+                walked.append(ename)
+                element = self.xml.find("/".join(walked))
+                if element is None:
+                    element = ET.Element(ename)
+                    last_xml.append(element)
+                last_xml = element
+            element = last_xml
+
+        element.text = text
+        return element 
+
     @property
     def attrib(self): #backwards compatibility
             return self
@@ -469,18 +512,6 @@ class ElementBase(object):
                             return False
             return True
 
-    def _setSubText(self, name, attrib={}, text=None):
-            if '}' not in name:
-                    name = "{%s}%s" % (self.namespace, name)
-            if text is None or text == '':
-                    return self.__delitem__(name)
-            stanza = self.xml.find(name)
-            if stanza is None:
-                    stanza = ET.Element(name)
-                    self.xml.append(stanza)
-            stanza.text = text
-            return stanza
-
     def _delSub(self, name):
             if '}' not in name:
                     name = "{%s}%s" % (self.namespace, name)

tests/test_elementbase.py

@@ -301,5 +301,56 @@ class TestElementBase(SleekTest):
         self.failUnless(stanza['bar'] == 'found', 
             "_getSubText value incorrect: %s." % stanza['bar'])
 
+    def testSubElement(self):
+        """Test setting the contents of a sub element."""
+
+        class TestStanza(ElementBase):
+            name = "foo"
+            namespace = "foo"
+            interfaces = set(('bar', 'baz'))
+
+            def setBaz(self, value):
+                self._setSubText("wrapper/baz", text=value)
+
+            def getBaz(self):
+                return self._getSubText("wrapper/baz")
+
+            def setBar(self, value):
+                self._setSubText("wrapper/bar", text=value)
+
+            def getBar(self):
+                return self._getSubText("wrapper/bar")
+
+        stanza = TestStanza()
+        stanza['bar'] = 'a'
+        stanza['baz'] = 'b'
+        self.checkStanza(TestStanza, stanza, """
+          <foo xmlns="foo">
+            <wrapper>
+              <bar>a</bar>
+              <baz>b</baz>
+            </wrapper>
+          </foo>
+        """)
+        stanza._setSubText('bar', text='', keep=True)
+        self.checkStanza(TestStanza, stanza, """
+          <foo xmlns="foo">
+            <wrapper>
+              <bar />
+              <baz>b</baz>
+            </wrapper>
+          </foo>
+        """, use_values=False)
+
+        stanza['bar'] = 'a'
+        stanza._setSubText('bar', text='')
+        self.checkStanza(TestStanza, stanza, """
+          <foo xmlns="foo">
+            <wrapper>
+              <baz>b</baz>
+            </wrapper>
+          </foo>
+        """)
+
 
 suite = unittest.TestLoader().loadTestsFromTestCase(TestElementBase)