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 814273d93b977bfd660ca6b16ee1a5b6b4adb6cf..c259867a1934a52045c8afecd0502ecfc342a28a 100644 (file)
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -4098,11 +4098,13 @@ 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 bb328ce42f757b9a8ef529cb1cdd34bd283406ae..35ce501d5b0fb9e403035825373c1dc114cc99f0 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,
@@ -87,6 +89,10 @@ start(Host, _Opts) ->
                       ?MODULE, get_jid_info, 70),
     ejabberd_hooks:add(roster_process_item, HostB,
                       ?MODULE, process_item, 50),
+    ejabberd_hooks:add(user_available_hook, HostB,
+                      ?MODULE, user_available, 50),
+    ejabberd_hooks:add(unset_presence_hook, HostB,
+                      ?MODULE, unset_presence, 50),
     ejabberd_hooks:add(register_user, HostB,
                       ?MODULE, register_user, 50),
     ejabberd_hooks:add(anonymous_purge_hook, HostB,
@@ -114,6 +120,10 @@ stop(Host) ->
                          ?MODULE, get_jid_info, 70),
     ejabberd_hooks:delete(roster_process_item, HostB,
                          ?MODULE, process_item, 50),
+    ejabberd_hooks:delete(user_available_hook, HostB,
+                         ?MODULE, user_available, 50),
+    ejabberd_hooks:delete(unset_presence_hook, HostB,
+                         ?MODULE, unset_presence, 50),
     ejabberd_hooks:delete(register_user, HostB,
                          ?MODULE, register_user, 50),
     ejabberd_hooks:delete(anonymous_purge_hook, HostB,
@@ -128,7 +138,6 @@ get_user_roster(Items, {U, S}) when is_binary(U) ->
     get_user_roster(Items, {binary_to_list(U), binary_to_list(S)});
 get_user_roster(Items, US) ->
     {U, S} = US,
-    USB = {list_to_binary(U), list_to_binary(S)},
     DisplayedGroups = get_user_displayed_groups(US),
     %% Get shared roster users in all groups and remove self: 
     SRUsers = 
@@ -136,9 +145,9 @@ get_user_roster(Items, US) ->
          fun(Group, Acc1) ->
                  GroupName = get_group_name(S, Group),
                  lists:foldl(
-                   fun(UserServerB, Acc2) ->
-                           if UserServerB == USB -> Acc2;
-                              true -> dict:append(UserServerB, 
+                   fun(UserServer, Acc2) ->
+                           if UserServer == US -> Acc2;
+                              true -> dict:append(UserServer,
                                                   GroupName,
                                                   Acc2)
                            end
@@ -506,27 +515,47 @@ get_group_opt(Host, Group, Opt, Default) ->
            Default
     end.
 
-%% @spec(Host::string(), Group::string()) -> [{Username::binary(), Server::binary()}]
+get_online_users(Host) ->
+    lists:usort([{binary_to_list(U), binary_to_list(S)}
+                || {U, S, _} <-
+                       ejabberd_sm:get_vh_session_list(list_to_binary(Host))]).
+
+%% @spec(Host::string(), Group::string()) -> [{Username::string(), Server::string()}]
 get_group_users(HostB, Group) when is_binary(HostB) ->
     get_group_users(binary_to_list(HostB), Group);
+
 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).
 
-%% @spec(User::any(), Host::string(), Group::string(), GroupOpts) -> [{Username::binary(), Server::binary()}]
-get_group_users(User, HostB, Group, GroupOpts) when is_binary(HostB) ->
-    get_group_users(User, binary_to_list(HostB), Group, GroupOpts);
-get_group_users(_User, Host, Group, GroupOpts) ->
+%% @spec(Host::string(), Group::string(), GroupOpts) -> [{Username::binary(), Server::binary()}]
+get_group_users(HostB, Group, GroupOpts) when is_binary(HostB) ->
+    get_group_users(binary_to_list(HostB), 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) ->
@@ -545,13 +574,22 @@ get_group_name(Host, Group) ->
     get_group_opt(Host, Group, name, Group).
 
 %% @spec(Host::string)
-%% @doc Get list of names of groups that have @all@ in the memberlist
+%% @doc Get list of names of groups that have @all@ or @online@ in the memberlist
 get_special_users_groups(HostB) when is_binary(HostB)->
     get_special_users_groups(binary_to_list(HostB));
 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)).
 
@@ -712,13 +750,17 @@ 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))
     catch
        _ ->
            ok
     end.
 
+push_user_to_displayed(User, Server, Group, Subscription) when is_binary(User) ->
+    LUser = binary_to_list(User),
+    LServer = binary_to_list(Server),
+    push_user_to_displayed(LUser, LServer, Group, Subscription);
 push_user_to_displayed(LUser, LServer, Group, Subscription) ->
     GroupsOpts = groups_with_opts(LServer),
     GroupOpts = proplists:get_value(Group, GroupsOpts, []),
@@ -728,7 +770,8 @@ 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)).
 
@@ -772,6 +815,54 @@ push_roster_item(User, Server, ContactU, ContactS, GroupName, Subscription) ->
                   groups = [GroupName]},
     push_item(User, Server, exmpp_jid:make(Server), Item).
 
+user_available(New) ->
+    LUser = exmpp_jid:node(New),
+    LServer = exmpp_jid:domain(New),
+    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(binary_to_list(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(User, Server, Resource, Status) ->
+    LUser = binary_to_list(User),
+    LServer = binary_to_list(Server),
+    Resources = ejabberd_sm:get_user_resources(User, Server),
+    ?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
 %%---------------------
@@ -874,6 +965,7 @@ 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),
@@ -883,7 +975,14 @@ 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(re:split(Description, "\n", [{return, list}])),
     FGroup =
@@ -972,6 +1071,8 @@ shared_roster_group_parse_query(Host, Group, Query) ->
                          case SJID of
                              "@all@" ->
                                  USs;
+                             "@online@" ->
+                                 USs;
                              _ ->
                                  try
                                      JID = exmpp_jid:parse(SJID),
@@ -987,10 +1088,15 @@ 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;