view mod_pubsub_eventsource/mod_pubsub_eventsource.lua @ 5186:fa3059e653fa

mod_http_oauth2: Implement the Implicit flow Everyone says this is insecure and bad, but it's also the only thing that makes sense for e.g. pure JavaScript clients, but hey implement this even more complicated thing instead!
author Kim Alvefur <zash@zash.se>
date Thu, 02 Mar 2023 22:06:50 +0100
parents 0329cf8cdecb
children
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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";
		"Access-Control-Allow-Origin: *";
		"Access-Control-Allow-Methods: GET";
		"Access-Control-Max-Age: 7200";
		"";
		"";
	}, "\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 item = event.item;
	if (item.name == "json" and item.attr.xmlns == "urn:xmpp:json:0") or (item.name == "data" and item.attr.xmlns == "https://prosody.im/protocol/data") then
		item = item[1];
	end
	local data = "data: "..tostring(item):gsub("\n", "\ndata: ").."\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);