add nsms.lang app which takes care of activating and setting profile …

…languages

nsms/lang/app.py

@@ -0,0 +1,90 @@
+from rapidsms.apps.base import AppBase
+from nsms.parser import Parser
+from nsms.text.models import gettext as _
+from nsms.utils import get_sms_profile
+from django.conf import settings
+from django.utils import translation
+import re
+
+# hackery to make sure our translation database contains all our the strings used in this app
+_('lang-current-lang', "Your language is set to {{ language }}.")
+_('lang-unknown-language', "Sorry, the language code '{{ code }}' is not supported.")
+_('lang-set-success', "Success, your language is now set to {{ language }}.")
+
+class App(AppBase):
+    """
+    This app is responsible for setting and changing a user's preferred language.
+
+    In order for this app to do it's magic, you need to define what your SMS profile in 
+    your settings_common.py:
+
+           SMS_PROFILE = 'chws.chw'
+
+    The language app will respond to messages that begin with the keyword 'lang'.  Without
+    an argument it will respond with the currently selected language, with an argument it
+    will try to find a configured language with that name and set it, eg:
+
+           lang en[_us]
+           lang rw
+    """
+    def handle (self, message):
+        profile = get_sms_profile(message.connection)
+
+        # handle activating the appropriate SMS language
+
+        # if this connection has a profile, use that language
+        if profile:
+            translation.activate(profile.language)
+
+        # otherwise use the default SMS language
+        else:
+            translation.activate(settings.DEFAULT_SMS_LANGUAGE)
+
+        parser = Parser(message.text)
+
+        # check whether this is a lang message
+        keyword = parser.next_keyword(['lang'])
+        if keyword:
+            if not profile:
+                message.respond(_('lang-unknown-user', "Sorry, your phone number is not registered."))
+                return True
+
+            # just querying the language
+            language = parser.next_word()
+            if not language:
+                message.respond(_('lang-current-lang', "Your language is set to {{ language }}.", dict(language=profile.get_language_display())))
+                return True
+
+            else:
+                # lowercase the language they passed us
+                language = language.lower()
+
+                lang_mapping = dict()
+                for lang in settings.LANGUAGES:
+                    code = lang[0].lower()
+                    lang_mapping[code] = code
+
+                    parts = code.split('_')
+                    if not parts[0] in lang_mapping:
+                        lang_mapping[parts[0]] = code
+
+                # this language doesn't exit
+                if not language.lower() in lang_mapping:
+                    message.respond(_('lang-unknown-language', "Sorry, the language code '{{ code }}' is not supported.", dict(code=language.lower())))
+                    return True
+
+                profile.language = lang_mapping[language.lower()]
+                profile.save()
+
+                # activate the new language
+                translation.activate(profile.language)
+                message.respond(_('lang-set-success', "Success, your language is now set to {{ language }}.", dict(language=profile.get_language_display())))
+
+                return True
+
+        return False
+
+
+
+
+

nsms/utils/__init__.py

@@ -1,4 +1,37 @@
 from django.contrib.auth.models import User, Group
+from django.conf import settings
+import sys
+
+def import_from_string(kls):
+    """
+    Used to load a class object dynamically by name
+    """
+    parts = kls.split('.')
+    module = ".".join(parts[:-1])
+    m = __import__(module)
+    for comp in parts[1:]:
+        m = getattr(m, comp)            
+    return m
+
+def get_sms_profile(connection):
+    """
+    Given a connection, looks up the SMS profile using the SMS_PROFILE model registered in settings.py
+    """
+    profile_class_name = getattr(settings, 'SMS_PROFILE', None)
+
+    # no SMS_PROFILE set, then return nothing
+    if not profile_class_name:
+        return None
+
+    profile_class = import_from_string(profile_class_name)
+
+    # see if we can find a match for that connection
+    matches = profile_class.objects.filter(connection=connection)
+    if matches:
+        return matches[0]
+
+    else:
+        return None
 
 def get_connection_user(connection):
     """