Ticket #5025: updated-truncatechars-5075.diff

django/utils/text.py

@@ -1 +1 @@
 import re
+import unicodedata
 from django.utils.encoding import force_unicode
 from django.utils.functional import allow_lazy
 from django.utils.translation import ugettext_lazy, ugettext as _
@@ -36 +37 @@
     return u''.join(_generator())
 wrap = allow_lazy(wrap, unicode)
 
+def truncate_chars(s, num, end_text='...'):
+    """Truncates a string after a certain number of characters. Takes an
+    optional argument of what should be used to notify that the string has been
+    truncated, defaulting to ellipsis (...)"""
+    s = force_unicode(s)
+    length = int(num)
+    
+    normalized = unicodedata.normalize('NFC', s)
+    
+    # If the text is short enough, we can bail out right now
+    if len(normalized) <= length:
+        return normalized
+    
+    translated_end_text = _(end_text)
+    len_end_text = len(translated_end_text)
+    
+    end_index = max(length-len_end_text, 0)
+    while unicodedata.combining(normalized[end_index]) and end_index < len(normalized):
+        end_index += 1
+    
+    return u'%s%s' % (normalized[:end_index], translated_end_text)
+truncate_chars = allow_lazy(truncate_chars, unicode)
+
 def truncate_words(s, num, end_text='...'):
     """Truncates a string after a certain number of words. Takes an optional
     argument of what should be used to notify that the string has been

django/template/defaultfilters.py

@@ -251 +251 @@
 title.is_safe = True
 title = stringfilter(title)
 
+def truncatechars(value, arg):
+    """
+    Truncates a string after a certain number of characters.
+    
+    Argument: Number of characters to truncate after.
+    """
+    from django.utils.text import truncate_chars
+    try:
+        length = int(arg)
+    except ValueError: # Invalid literal for int().
+        return value # Fail silently.
+    return truncate_chars(value, length)
+truncatechars.is_safe = True
+truncatechars = stringfilter(truncatechars)
+
 def truncatewords(value, arg):
     """
     Truncates a string after a certain number of words.

tests/regressiontests/utils/text.py

@@ +1 @@
+# -*- coding: utf-8 -*-
 import unittest
 
 from django.utils import text
@@ -4 +5 @@
 
 class TestUtilsText(unittest.TestCase):
 
+    def test_truncate_chars(self):
+        self.assertEqual(u'The quick brown fox jumped over the lazy dog.',
+            text.truncate_chars(u'The quick brown fox jumped over the lazy dog.', 100))
+        self.assertEqual(u'The quick brown fox ...',
+            text.truncate_chars('The quick brown fox jumped over the lazy dog.', 23))
+        self.assertEqual(u'The quick brown fox ....',
+            text.truncate_chars('The quick brown fox jumped over the lazy dog.', 24, '....'))
+        
+        # Ensure that we normalize our unicode data first
+        nfc = u'o\xfco\xfco\xfco\xfc'
+        nfd = u'ou\u0308ou\u0308ou\u0308ou\u0308'
+        self.assertEqual(u'oüoüoüoü', text.truncate_chars(nfc, 8))
+        self.assertEqual(u'oüoüoüoü', text.truncate_chars(nfd, 8))
+        self.assertEqual(u'oü...', text.truncate_chars(nfc, 5))
+        self.assertEqual(u'oü...', text.truncate_chars(nfd, 5))
+        
+        # We shouldn't split combining characters up
+        self.assertEqual(u'__B\u030A...',
+            text.truncate_chars(u'__B\u030A____', 6))
+        
+        # Make a best effort to shorten to the desired length, but requesting
+        # a length shorter than the ellipsis shouldn't break
+        self.assertEqual(u'...', text.truncate_chars(u'asdf', 1))
+
     def test_truncate_words(self):
         self.assertEqual(u'The quick brown fox jumped over the lazy dog.',
             text.truncate_words(u'The quick brown fox jumped over the lazy dog.', 10))

docs/ref/templates/builtins.txt

@@ -1989 +1989 @@
 
 If ``value`` is ``"my first post"``, the output will be ``"My First Post"``.
 
+.. templatefilter:: truncatechars
+
+truncatechars
+~~~~~~~~~~~~~
+
+Truncates a string after a certain number of characters.
+
+**Argument:** Number of characters to truncate after
+
+For example::
+
+    {{ value|truncatechars:11 }}
+
+If ``value`` is ``"Joel is a slug"``, the output will be ``"Joel is ..."``.
+
 .. templatefilter:: truncatewords
 
 truncatewords