custom template filter to help language display

frontend/templatetags/lang_utils.py

@@ -0,0 +1,51 @@
+"""
+The truncatechars filter is part of Django dev, but we're on 1.3.1
+The following is the filter and its dependencies
+To use this filter, put "{% load truncatechars %}" at the beginning of your template, 
+then {{ myvariable|truncatechars:num }}
+"""
+import unicodedata
+from django.template.base import Library
+from django.template.defaultfilters import stringfilter
+from django.utils.translation import get_language_info
+
+register = Library()
+
+custom_language_info = {'xx': {'name':'unknown', 'name_local':'unknown'},
+                        'un': {'name':'??', 'name_local':'??'},
+                        'zh': {'name':'chinese', 'name_local':u'\u4E2D\u6587'},
+                        'la': {'name':'Latin', 'name_local':'latin'},
+                        }
+                        
+        
+# need to not throw exceptions when no built-in lang yet     
+@register.filter()
+@stringfilter
+def ez_lang_name(value):
+    """
+    returns language name  without throwing exceptions.
+    """
+    try:
+        try:
+            li = get_language_info( value )
+        except KeyError: # Invalid literal for int().
+            li = custom_language_info[ value ]
+        return li['name']
+    except KeyError:
+        return value
+
+# need to not throw exceptions when no built-in lang yet     
+@register.filter()
+@stringfilter
+def ez_lang_name_local(value):
+    """
+    returns language name in its language without throwing exceptions.
+    """
+    try:
+        try:
+            li = get_language_info( value )
+        except KeyError: # Invalid literal for int().
+            li = custom_language_info[ value ]
+        return li['name_local']
+    except KeyError:
+        return value