Add support for '@online@' Shared Roster Group (thanks to Martin Langhoff)(EJAB-1391)

New version of the @online@ patch originally by Collabora.
Notes:
- the presence push is mediated via the group rather than
  per user - this may reduce memory footprint... _if_ ejabberd
  has some smart optimisation in that codepath
- it assumes that any group with membership @online@ _displays_
  online as well -- this is a simplification and breaks the
  decoupling that ejabberd has in this regard.

diff --git a/doc/guide.tex b/doc/guide.tex
index e0bb42e4cbcdec6f3efbf9e5a5156b0631d24ae0..2bacd57c9791b97639ee703df847660c0de63265 100644 (file)
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -4055,11 +4055,13 @@ has a unique identification and the following parameters:
 \item[Name] The name of the group, which will be displayed in the roster.
 \item[Description] The description of the group. This parameter does not affect
   anything.
-\item[Members] A list of full JIDs of group members, entered one per line in
+\item[Members] A list of JIDs of group members, entered one per line in
   the Web Admin.
-  To put as members all the registered users in the virtual hosts,
-  you can use the special directive: @all@.
-  Note that this directive is designed for a small server with just a few hundred users.
+  The special member directive \term{@all@}
+  represents all the registered users in the virtual host;
+  which is only recommended for a small server with just a few hundred users.
+  The special member directive \term{@online@}
+  represents the online users in the virtual host.
 \item[Displayed groups] A list of groups that will be in the rosters of this
   group's members.
 \end{description}

diff --git a/src/mod_shared_roster.erl b/src/mod_shared_roster.erl
index 13348cffbe77af431f65374e26f15c274afc45a7..14879cce02773e79b72f75e113c19181b9a29842 100644 (file)
--- a/src/mod_shared_roster.erl
+++ b/src/mod_shared_roster.erl
@@ -37,6 +37,8 @@
         process_item/2,
         in_subscription/6,
         out_subscription/4,
+        user_available/1,
+        unset_presence/4,
         register_user/2,
         remove_user/2,
         list_groups/1,
@@ -85,6 +87,10 @@ start(Host, _Opts) ->
                       ?MODULE, get_jid_info, 70),
     ejabberd_hooks:add(roster_process_item, Host,
                       ?MODULE, process_item, 50),
+    ejabberd_hooks:add(user_available_hook, Host,
+                      ?MODULE, user_available, 50),
+    ejabberd_hooks:add(unset_presence_hook, Host,
+                      ?MODULE, unset_presence, 50),
     ejabberd_hooks:add(register_user, Host,
                       ?MODULE, register_user, 50),
     ejabberd_hooks:add(remove_user, Host,
@@ -109,6 +115,10 @@ stop(Host) ->
                          ?MODULE, get_jid_info, 70),
     ejabberd_hooks:delete(roster_process_item, Host,
                          ?MODULE, process_item, 50),
+    ejabberd_hooks:delete(user_available_hook, Host,
+                         ?MODULE, user_available, 50),
+    ejabberd_hooks:delete(unset_presence_hook, Host,
+                         ?MODULE, unset_presence, 50),
     ejabberd_hooks:delete(register_user, Host,
                          ?MODULE, register_user, 50),
     ejabberd_hooks:delete(remove_user, Host,
@@ -470,21 +480,38 @@ get_group_opt(Host, Group, Opt, Default) ->
            Default
     end.
 
+get_online_users(Host) ->
+    lists:usort([{U, S} || {U, S, _} <- ejabberd_sm:get_vh_session_list(Host)]).
+
 get_group_users(Host, Group) ->
     case get_group_opt(Host, Group, all_users, false) of
        true ->
            ejabberd_auth:get_vh_registered_users(Host);
        false ->
            []
-    end ++ get_group_explicit_users(Host, Group).
+    end ++
+    case get_group_opt(Host, Group, online_users, false) of
+       true ->
+           get_online_users(Host);
+       false ->
+           []
+    end ++
+    get_group_explicit_users(Host, Group).
 
-get_group_users(_User, Host, Group, GroupOpts) ->
+get_group_users(Host, Group, GroupOpts) ->
     case proplists:get_value(all_users, GroupOpts, false) of
        true ->
            ejabberd_auth:get_vh_registered_users(Host);
        false ->
            []
-    end ++ get_group_explicit_users(Host, Group).
+    end ++
+    case proplists:get_value(online_users, GroupOpts, false) of
+       true ->
+           get_online_users(Host);
+       false ->
+           []
+    end ++
+    get_group_explicit_users(Host, Group).
 
 %% @spec (Host::string(), Group::string()) -> [{User::string(), Server::string()}]
 get_group_explicit_users(Host, Group) ->
@@ -502,11 +529,20 @@ get_group_explicit_users(Host, Group) ->
 get_group_name(Host, Group) ->
     get_group_opt(Host, Group, name, Group).
 
-%% Get list of names of groups that have @all@ in the memberlist
+%% Get list of names of groups that have @all@/@online@/etc in the memberlist
 get_special_users_groups(Host) ->
     lists:filter(
       fun(Group) ->
              get_group_opt(Host, Group, all_users, false)
+                 orelse get_group_opt(Host, Group, online_users, false)
+      end,
+      list_groups(Host)).
+
+%% Get list of names of groups that have @online@ in the memberlist
+get_special_users_groups_online(Host) ->
+    lists:filter(
+      fun(Group) ->
+             get_group_opt(Host, Group, online_users, false)
       end,
       list_groups(Host)).
 
@@ -661,7 +697,7 @@ push_user_to_members(User, Server, Subscription) ->
              lists:foreach(
                fun({U, S}) ->
                        push_roster_item(U, S, LUser, LServer, GroupName, Subscription)
-               end, get_group_users(LUser, LServer, Group, GroupOpts))
+               end, get_group_users(LServer, Group, GroupOpts))
       end, lists:usort(SpecialGroups++UserGroups)).
 
 push_user_to_displayed(LUser, LServer, Group, Subscription) ->
@@ -673,7 +709,8 @@ push_user_to_displayed(LUser, LServer, Group, Subscription) ->
 
 push_user_to_group(LUser, LServer, Group, GroupName, Subscription) ->
     lists:foreach(
-      fun({U, S}) ->
+      fun({U, S}) when (U == LUser) and (S == LServer) -> ok;
+         ({U, S}) ->
              push_roster_item(U, S, LUser, LServer, GroupName, Subscription)
       end, get_group_users(LServer, Group)).
 
@@ -757,6 +794,51 @@ ask_to_pending(subscribe) -> out;
 ask_to_pending(unsubscribe) -> none;
 ask_to_pending(Ask) -> Ask.
 
+user_available(New) ->
+    LUser = New#jid.luser,
+    LServer = New#jid.lserver,
+    Resources = ejabberd_sm:get_user_resources(LUser, LServer),
+    ?DEBUG("user_available for ~p @ ~p (~p resources)",
+          [LUser, LServer, length(Resources)]),
+    case length(Resources) of
+       %% first session for this user
+       1 ->
+           %% This is a simplification - we ignore he 'display'
+           %% property - @online@ is always reflective.
+           OnlineGroups = get_special_users_groups_online(LServer),
+           lists:foreach(
+             fun(OG) ->
+                     ?DEBUG("user_available: pushing  ~p @ ~p grp ~p",
+                            [LUser, LServer, OG ]),
+                     push_user_to_displayed(LUser, LServer, OG, both)
+             end, OnlineGroups);
+       _ ->
+           ok
+    end.
+
+unset_presence(LUser, LServer, Resource, Status) ->
+    Resources = ejabberd_sm:get_user_resources(LUser, LServer),
+    ?DEBUG("unset_presence for ~p @ ~p / ~p -> ~p (~p resources)",
+          [LUser, LServer, Resource, Status, length(Resources)]),
+    %% if user has no resources left...
+    case length(Resources) of
+       0 ->
+           %% This is a simplification - we ignore he 'display'
+           %% property - @online@ is always reflective.
+           OnlineGroups = get_special_users_groups_online(LServer),
+           %% for each of these groups...
+           lists:foreach(
+             fun(OG) ->
+                     %% Push removal of the old user to members of groups
+                     %% where the group that this uwas members was displayed
+                     push_user_to_displayed(LUser, LServer, OG, remove),
+                     %% Push removal of members of groups that where
+                     %% displayed to the group which thiuser has left
+                     push_displayed_to_user(LUser, LServer, OG, LServer,remove)
+             end, OnlineGroups);
+       _ ->
+           ok
+    end.
 
 %%---------------------
 %% Web Admin
@@ -860,6 +942,7 @@ shared_roster_group(Host, Group, Query, Lang) ->
     Name = get_opt(GroupOpts, name, ""),
     Description = get_opt(GroupOpts, description, ""),
     AllUsers = get_opt(GroupOpts, all_users, false),
+    OnlineUsers = get_opt(GroupOpts, online_users, false),
     %%Disabled = false,
     DisplayedGroups = get_opt(GroupOpts, displayed_groups, []),
     Members = mod_shared_roster:get_group_explicit_users(Host, Group),
@@ -869,7 +952,14 @@ shared_roster_group(Host, Group, Query, Lang) ->
                "@all@\n";
            true ->
                []
-       end ++ [[us_to_list(Member), $\n] || Member <- Members],
+       end ++
+       if
+           OnlineUsers ->
+               "@online@\n";
+           true ->
+               []
+       end ++
+       [[us_to_list(Member), $\n] || Member <- Members],
     FDisplayedGroups = [[DG, $\n] || DG <- DisplayedGroups],
     DescNL = length(element(2, regexp:split(Description, "\n"))),
     FGroup =
@@ -953,6 +1043,8 @@ shared_roster_group_parse_query(Host, Group, Query) ->
                          case SJID of
                              "@all@" ->
                                  USs;
+                             "@online@" ->
+                                 USs;
                              _ ->
                                  case jlib:string_to_jid(SJID) of
                                      JID when is_record(JID, jid) ->
@@ -967,10 +1059,15 @@ shared_roster_group_parse_query(Host, Group, Query) ->
                    true -> [{all_users, true}];
                    false -> []
                end,
+           OnlineUsersOpt =
+               case lists:member("@online@", SJIDs) of
+                   true -> [{online_users, true}];
+                   false -> []
+               end,
 
            mod_shared_roster:set_group_opts(
              Host, Group,
-             NameOpt ++ DispGroupsOpt ++ DescriptionOpt ++ AllUsersOpt),
+             NameOpt ++ DispGroupsOpt ++ DescriptionOpt ++ AllUsersOpt ++ OnlineUsersOpt),
 
            if
                NewMembers == error -> error;