Gave new_string() the ability to create subclasses of

  NavigableString. [bug=1181986]

4 files changed, 26 insertions, 3 deletions

diff --git a/NEWS.txt b/NEWS.txt
index 2c8541c..50b3cca 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -1,5 +1,8 @@
 = 4.2.1 (Unreleased) =
 
+* Gave new_string() the ability to create subclasses of
+  NavigableString. [bug=1181986]
+
 * Fixed test failures when lxml is not installed. [bug=1181589]
 
 * html5lib now supports Python 3. Fixed some Python 2-specific
diff --git a/bs4/__init__.py b/bs4/__init__.py
index a5e7a86..0195bcb 100644
--- a/bs4/__init__.py
+++ b/bs4/__init__.py
@@ -17,7 +17,7 @@ http://www.crummy.com/software/BeautifulSoup/bs4/doc/
 """
 
 __author__ = "Leonard Richardson (leonardr@segfault.org)"
-__version__ = "4.2.0"
+__version__ = "4.2.1"
 __copyright__ = "Copyright (c) 2004-2013 Leonard Richardson"
 __license__ = "MIT"
 
@@ -201,9 +201,9 @@ class BeautifulSoup(Tag):
         """Create a new tag associated with this soup."""
         return Tag(None, self.builder, name, namespace, nsprefix, attrs)
 
-    def new_string(self, s):
+    def new_string(self, s, subclass=NavigableString):
         """Create a new NavigableString associated with this soup."""
-        navigable = NavigableString(s)
+        navigable = subclass(s)
         navigable.setup()
         return navigable
 
diff --git a/bs4/tests/test_tree.py b/bs4/tests/test_tree.py
index 4f12d20..c39b3f7 100644
--- a/bs4/tests/test_tree.py
+++ b/bs4/tests/test_tree.py
@@ -689,6 +689,12 @@ class TestTagCreation(SoupTest):
         self.assertEqual("foo", s)
         self.assertTrue(isinstance(s, NavigableString))
 
+    def test_new_string_can_create_navigablestring_subclass(self):
+        soup = self.soup("")
+        s = soup.new_string("foo", Comment)
+        self.assertEqual("foo", s)
+        self.assertTrue(isinstance(s, Comment))
+
 class TestTreeModification(SoupTest):
 
     def test_attribute_modification(self):
diff --git a/doc/source/index.rst b/doc/source/index.rst
index e254855..a91854c 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -1806,6 +1806,20 @@ Python string in to ``append()``, or you can call the factory method
    tag.contents
    # [u'Hello', u' there']
 
+If you want to create a comment or some other subclass of
+``NavigableString``, pass that class as the second argument to
+``new_string()``::
+
+   from bs4 import Comment
+   new_comment = soup.new_string("Nice to see you.", Comment)
+   tag.append(new_comment)
+   tag
+   # <b>Hello there<!--Nice to see you.--></b>
+   tag.contents
+   # [u'Hello', u' there', u'Nice to see you.']
+
+(This is a new feature in Beautiful Soup 4.2.1.)
+
 What if you need to create a whole new tag?  The best solution is to
 call the factory method ``BeautifulSoup.new_tag()``::