mod_mam/rsm.lib.lua

   1 local stanza = require"util.stanza".stanza;
   2 local tostring, tonumber = tostring, tonumber;
   3 local type = type;
   4 local pairs = pairs;
   5
   6 local xmlns_rsm = 'http://jabber.org/protocol/rsm';
   7
   8 local element_parsers = {};
   9
  10 do
  11         local parsers = element_parsers;
  12         local function xs_int(st)
  13                 return tonumber((st:get_text()));
  14         end
  15         local function xs_string(st)
  16                 return st:get_text();
  17         end
  18
  19         parsers.after = xs_string;
  20         parsers.before = function(st)
  21                         local text = st:get_text();
  22                         return text == "" or text;
  23                 end;
  24         parsers.max = xs_int;
  25         parsers.index = xs_int;
  26
  27         parsers.first = function(st)
  28                         return { index = tonumber(st.attr.index); st:get_text() };
  29                 end;
  30         parsers.last = xs_string;
  31         parsers.count = xs_int;
  32 end
  33
  34 local element_generators = setmetatable({
  35         first = function(st, data)
  36                 if type(data) == "table" then
  37                         st:tag("first", { index = data.index }):text(data[1]):up();
  38                 else
  39                         st:tag("first"):text(tostring(data)):up();
  40                 end
  41         end;
  42         before = function(st, data)
  43                 if data == true then
  44                         st:tag("before"):up();
  45                 else
  46                         st:tag("before"):text(tostring(data)):up();
  47                 end
  48         end
  49 }, {
  50         __index = function(_, name)
  51                 return function(st, data)
  52                         st:tag(name):text(tostring(data)):up();
  53                 end
  54         end;
  55 });
  56
  57
  58 local function parse(set)
  59         local rs = {};
  60         for tag in set:childtags() do
  61                 local name = tag.name;
  62                 local parser = name and element_parsers[name];
  63                 if parser then
  64                         rs[name] = parser(tag);
  65                 end
  66         end
  67         return rs;
  68 end
  69
  70 local function generate(t)
  71         local st = stanza("set", { xmlns = xmlns_rsm });
  72         for k,v in pairs(t) do
  73                 if element_parsers[k] then
  74                         element_generators[k](st, v);
  75                 end
  76         end
  77         return st;
  78 end
  79
  80 local function get(st)
  81         local set = st:get_child("set", xmlns_rsm);
  82         if set and #set.tags > 0 then
  83                 return parse(set);
  84         end
  85 end
  86
  87 return { parse = parse, generate = generate, get = get };