module("pubsub", package.seeall); local service = {}; local service_mt = { __index = service }; local default_config = { broadcaster = function () end; get_affiliation = function () end; capabilities = {}; }; function new(config) config = config or {}; return setmetatable({ config = setmetatable(config, { __index = default_config }); affiliations = {}; nodes = {}; }, service_mt); end function service:may(node, actor, action) if actor == true then return true; end local node_obj = self.nodes[node]; local node_aff = node_obj and node_obj.affiliations[actor]; local service_aff = self.affiliations[actor] or self.config.get_affiliation(actor, node, action) or "none"; local node_capabilities = node_obj and node_obj.capabilities; local service_capabilities = self.config.capabilities; -- Check if node allows/forbids it if node_capabilities then local caps = node_capabilities[node_aff or service_aff]; if caps then local can = caps[action]; if can ~= nil then return can; end end end -- Check service-wide capabilities instead local caps = service_capabilities[node_aff or service_aff]; if caps then local can = caps[action]; if can ~= nil then return can; end end return false; end function service:set_affiliation(node, actor, jid, affiliation) -- Access checking if not self:may(node, actor, "set_affiliation") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if not node_obj then return false, "item-not-found"; end node_obj.affiliations[jid] = affiliation; local _, jid_sub = self:get_subscription(node, nil, jid); if not jid_sub and not self:may(node, jid, "be_unsubscribed") then local ok, err = self:add_subscription(node, nil, jid); if not ok then return ok, err; end elseif jid_sub and not self:may(node, jid, "be_subscribed") then local ok, err = self:add_subscription(node, nil, jid); if not ok then return ok, err; end end return true; end function service:add_subscription(node, actor, jid, options) -- Access checking local cap; if jid == actor or self.config.jids_equal(actor, jid) then cap = "subscribe"; else cap = "subscribe_other"; end if not self:may(node, actor, cap) then return false, "forbidden"; end if not self:may(node, jid, "be_subscribed") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if not node_obj then if not self.config.autocreate_on_subscribe then return false, "item-not-found"; else local ok, err = self:create(node, actor); if not ok then return ok, err; end end end node_obj.subscribers[jid] = options or true; return true; end function service:remove_subscription(node, actor, jid) -- Access checking local cap; if jid == actor or self.config.jids_equal(actor, jid) then cap = "unsubscribe"; else cap = "unsubscribe_other"; end if not self:may(node, actor, cap) then return false, "forbidden"; end if not self:may(node, jid, "be_unsubscribed") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if not node_obj then return false, "item-not-found"; end if not node_obj.subscribers[jid] then return false, "not-subscribed"; end node_obj.subscribers[jid] = nil; return true; end function service:get_subscription(node, actor, jid) -- Access checking local cap; if jid == actor or self.config.jids_equal(actor, jid) then cap = "get_subscription"; else cap = "get_subscription_other"; end if not self:may(node, actor, cap) then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if node_obj then return true, node_obj.subscribers[jid]; end end function service:create(node, actor) -- Access checking if not self:may(node, actor, "create") then return false, "forbidden"; end -- if self.nodes[node] then return false, "conflict"; end self.nodes[node] = { name = node; subscribers = {}; config = {}; data = {}; affiliations = {}; }; local ok, err = self:set_affiliation(node, true, actor, "owner"); if not ok then self.nodes[node] = nil; end return ok, err; end function service:publish(node, actor, id, item) -- Access checking if not self:may(node, actor, "publish") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if not node_obj then if not self.config.autocreate_on_publish then return false, "item-not-found"; end local ok, err = self:create(node, actor); if not ok then return ok, err; end node_obj = self.nodes[node]; end node_obj.data[id] = item; self.config.broadcaster(node, node_obj.subscribers, item); return true; end function service:retract(node, actor, id, retract) -- Access checking if not self:may(node, actor, "retract") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if (not node_obj) or (not node_obj.data[id]) then return false, "item-not-found"; end node_obj.data[id] = nil; if retract then self.config.broadcaster(node, node_obj.subscribers, retract); end return true end function service:get_items(node, actor, id) -- Access checking if not self:may(node, actor, "get_items") then return false, "forbidden"; end -- local node_obj = self.nodes[node]; if not node_obj then return false, "item-not-found"; end if id then -- Restrict results to a single specific item return true, { node_obj.data[id] }; else return true, node_obj.data; end end function service:get_nodes(actor) -- Access checking if not self:may(node, actor, "get_nodes") then return false, "forbidden"; end -- return true, self.nodes; end return _M;