New event callbacks to update the list of available applications when an extension is disabled/enabled.

fixed #185

admin/__init__.py

@@ -24,22 +24,27 @@ parameters.register_admin("PASSWORD_SCHEME", type="list", deflt="crypt",
 parameters.register_admin("ITEMS_PER_PAGE", type="int", deflt=30,
                           help=_("Number of displayed items per page"))
 
-#
-# Quick fix for #184
-#
-# Just catch the DatabaseError exception raised when runnning the
-# first ``syncdb`` command. 
-#
-try:
-    enabled_extensions = list(Extension.objects.filter(enabled=True))
-except DatabaseError:
-    enabled_extensions = []
+def enabled_applications():
+    """Return the list of currently enabled extensions
+
+    Quick fix for #184:
+
+    Just catch the DatabaseError exception raised when runnning the
+    first ``syncdb`` command.
+
+    :return: a list
+    """
+    result = [("admin", "admin"), ("userprefs", "userprefs")]
+    try:
+        exts = list(Extension.objects.filter(enabled=True))
+    except DatabaseError:
+        exts = []
+    result += map(lambda ext: (ext.name, ext.name), exts)
+    return sorted(result)
 
 parameters.register_admin("DEFAULT_TOP_REDIRECTION", type="list", deflt="admin",
                           app="general",
-                          values=sorted([("admin", "admin"), ("userprefs", "userprefs")] \
-                                            + map(lambda ext: (ext.name, ext.name), 
-                                                  enabled_extensions)),
+                          values=enabled_applications(),
                           help=_("The default redirection used when no application is specified"))
 
 def unset_default_topredirection(**kwargs):
@@ -51,4 +56,14 @@ def unset_default_topredirection(**kwargs):
     if topredirection == kwargs["ext"].name:
         parameters.save_admin("DEFAULT_TOP_REDIRECTION", "userprefs", app="general")
 
+def update_available_applications(**kwargs):
+    """Simple callback to update the list of available applications
+
+    Must be called each time an extension is disabled/enabled.
+    """
+    parameters.update_admin("DEFAULT_TOP_REDIRECTION", app="general",
+                            values=enabled_applications())
+
 events.register("ExtDisabled", unset_default_topredirection)
+events.register("ExtDisabled", update_available_applications)
+events.register("ExtEnabled", update_available_applications)

admin/views.py

@@ -596,16 +596,16 @@ def saveextensions(request):
             parts = k.split("_", 1)
             dbext = Extension.objects.get(name=parts[1])            
             if not dbext in actived_exts:
-                dbext.on()
                 dbext.enabled = True
                 dbext.save()
+                dbext.on()
             else:
                 found += [dbext]
     for ext in actived_exts:
         if not ext in found:
-            ext.off()
             ext.enabled = False
             ext.save()
+            ext.off()
     messages.info(request, _("Modifications applied."), fail_silently=True)
     return HttpResponseRedirect(reverse(admin.views.viewextensions))
 

lib/events.py

@@ -1,6 +1,9 @@
 # -*- coding: utf-8 -*-
 
 """
+:mod:`events` --- simple events handling
+----------------------------------------
+
 This module provides a simple way of managing events between Modoboa
 core application and additional components.
 

lib/parameters.py

@@ -36,7 +36,12 @@ def __is_defined(app, level, name):
 def __register(app, level, name, **kwargs):
     """Register a new parameter.
 
-    app corresponds to a core component (admin, main) or an extension.
+    ``app`` corresponds to a core component (admin, main) or to an
+    extension.
+
+    :param name: the application's name
+    :param level: the level this parameter is available from
+    :param name: the parameter's name
     """ 
     if not app in _params.keys():
         _params[app] = {}
@@ -53,7 +58,24 @@ def __register(app, level, name, **kwargs):
     for k, v in kwargs.iteritems():
         _params[app][level][name][k] = v
 
+def __update(app, level, name, **kwargs):
+    """Update a parameter's definition
+
+    :param app: the application's name
+    :param level: the level this parameter is available from
+    :param name: the parameter's name
+    """
+    if not app in _params.keys() or not level in _levels.keys() \
+            or not _params[app][level].has_key(name):
+        return
+    for k, v in kwargs.iteritems():
+        _params[app][level][name][k] = v
+
 def __guess_extension():
+    """Tries to guess the application's name by inspecting the stack
+
+    :return: a string or None
+    """
     modname = inspect.getmodule(inspect.stack()[2][0]).__name__
     m = re.match("(?:modoboa\.)?(?:extensions\.)?([^\.$]+)", modname)
     if m:
@@ -61,6 +83,13 @@ def __guess_extension():
     return None
 
 def register_admin(name, **kwargs):
+    """Register a new parameter (admin level)
+
+    Each parameter is associated to one application. If no application
+    is provided, the function tries to guess the appropriate one.
+
+    :param name: the parameter's name
+    """
     if kwargs.has_key("app"):
         app = kwargs["app"]
         del kwargs["app"]
@@ -68,6 +97,21 @@ def register_admin(name, **kwargs):
         app = __guess_extension()
     return __register(app, 'A', name, **kwargs)
 
+def update_admin(name, **kwargs):
+    """Update a parameter's definition (admin level)
+
+    Each parameter is associated to one application. If no application
+    is provided, the function tries to guess the appropriate one.
+
+    :param name: the parameter's name
+    """
+    if kwargs.has_key("app"):
+        app = kwargs["app"]
+        del kwargs["app"]
+    else:
+        app = __guess_extension()
+    return __update(app, 'A', name, **kwargs)
+
 def register_user(name, **kwargs):
     if kwargs.has_key("app"):
         app = kwargs["app"]