2 -- Copyright (C) 2008-2010 Matthew Wild
3 -- Copyright (C) 2008-2010 Waqas Hussain
5 -- This project is MIT/X11 licensed. Please see the
6 -- COPYING file in the source package for more information.
9 local t_insert, t_remove = table.insert, table.remove;
13 local new_filter_hooks = {};
15 local function initialize(session)
16 if not session.filters then
18 session.filters = filters;
20 function session.filter(type, data)
21 local filter_list = filters[type];
23 for i = 1, #filter_list do
24 data = filter_list[i](data, session);
25 if data == nil then break; end
32 for i=1,#new_filter_hooks do
33 new_filter_hooks[i](session);
36 return session.filter;
39 local function add_filter(session, type, callback, priority)
40 if not session.filters then
44 local filter_list = session.filters[type];
45 if not filter_list then
47 session.filters[type] = filter_list;
48 elseif filter_list[callback] then
49 return; -- Filter already added
52 priority = priority or 0;
57 until not filter_list[i] or filter_list[filter_list[i]] < priority;
59 t_insert(filter_list, i, callback);
60 filter_list[callback] = priority;
63 local function remove_filter(session, type, callback)
64 if not session.filters then return; end
65 local filter_list = session.filters[type];
66 if filter_list and filter_list[callback] then
67 for i=1, #filter_list do
68 if filter_list[i] == callback then
69 t_remove(filter_list, i);
70 filter_list[callback] = nil;
77 local function add_filter_hook(callback)
78 t_insert(new_filter_hooks, callback);
81 local function remove_filter_hook(callback)
82 for i=1,#new_filter_hooks do
83 if new_filter_hooks[i] == callback then
84 t_remove(new_filter_hooks, i);
90 initialize = initialize;
91 add_filter = add_filter;
92 remove_filter = remove_filter;
93 add_filter_hook = add_filter_hook;
94 remove_filter_hook = remove_filter_hook;