mod_pubsub_eventsource: An experimental plugin for allowing non-XMPP subscriptions to pubsub nodes over HTML5's server-sent events (SSE/EventSource) API
module:depends("http");
module:depends("pubsub");
local streams = {};
local service = hosts[module.host].modules.pubsub.service;
function client_closed(response)
local node = response._eventsource_node;
module:log("debug", "Destroying client for %q", node);
streams[node][response] = nil;
if next(streams[node]) == nil then
streams[node] = nil;
end
end
function serve_stream(event, node)
module:log("debug", "Client subscribed to: %s", node);
local response = event.response;
response.on_destroy = client_closed;
response._eventsource_node = node;
response.conn:write(table.concat({
"HTTP/1.1 200 OK";
"Content-Type: text/event-stream";
"";
"";
}, "\r\n"));
local clientlist = streams[node];
if not clientlist then
clientlist = {};
streams[node] = clientlist;
end
clientlist[response] = response.conn;
return true;
end
function handle_update(event)
module:log("debug", "Item published: %q", event.node);
local node = event.node;
local clientlist = streams[node];
local data = "data: "..tostring(event.item):gsub("\n", "\ndata: \n").."\n\n";
if not clientlist then module:log("debug", "No clients for %q", node); return; end
for response, conn in pairs(clientlist) do
conn:write(data);
end
end
module:provides("http", {
name = "eventsource";
route = {
["GET /*"] = serve_stream;
};
});
module:hook_object_event(service.events, "item-published", handle_update);