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node-red/red/runtime-api/comms.js
2018-05-01 12:28:15 +01:00

132 lines
4.2 KiB
JavaScript

/**
* Copyright JS Foundation and other contributors, http://js.foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
**/
/**
* @namespace RED.comms
*/
/**
* @typedef CommsConnection
* @type {object}
* @property {string} session - a unique session identifier
* @property {Object} user - the user associated with the connection
* @property {Function} send - publish a message to the connection
*/
var runtime;
var retained = {};
var connections = [];
function handleCommsEvent(event) {
publish(event.topic,event.data,event.retain);
}
function handleStatusEvent(event) {
publish("status/"+event.id,event.status,true);
}
function handleRuntimeEvent(event) {
runtime.log.trace("runtime event: "+JSON.stringify(event));
publish("notification/"+event.id,event.payload||{},event.retain);
}
function publish(topic,data,retain) {
if (retain) {
retained[topic] = data;
} else {
delete retained[topic];
}
connections.forEach(connection => connection.send(topic,data))
}
var api = module.exports = {
init: function(_runtime) {
runtime = _runtime;
connections = [];
retained = {};
runtime.events.removeListener("node-status",handleStatusEvent);
runtime.events.on("node-status",handleStatusEvent);
runtime.events.removeListener("runtime-event",handleRuntimeEvent);
runtime.events.on("runtime-event",handleRuntimeEvent);
runtime.events.removeListener("comms",handleCommsEvent);
runtime.events.on("comms",handleCommsEvent);
},
/**
* Registers a new comms connection
* @param {Object} opts
* @param {User} opts.user - the user calling the api
* @param {CommsConnection} opts.client - the client connection
* @return {Promise<Object>} - resolves when complete
* @memberof RED.comms
*/
addConnection: function(opts) {
connections.push(opts.client);
return Promise.resolve();
},
/**
* Unregisters a comms connection
* @param {Object} opts
* @param {User} opts.user - the user calling the api
* @param {CommsConnection} opts.client - the client connection
* @return {Promise<Object>} - resolves when complete
* @memberof RED.comms
*/
removeConnection: function(opts) {
for (var i=0;i<connections.length;i++) {
if (connections[i] === opts.client) {
connections.splice(i,1);
break;
}
}
return Promise.resolve();
},
/**
* Subscribes a comms connection to a given topic. Currently, all clients get
* automatically subscribed to everything and cannot unsubscribe. Sending a subscribe
* request will trigger retained messages to be sent.
* @param {Object} opts
* @param {User} opts.user - the user calling the api
* @param {CommsConnection} opts.client - the client connection
* @param {String} opts.topic - the topic to subscribe to
* @return {Promise<Object>} - resolves when complete
* @memberof RED.comms
*/
subscribe: function(opts) {
var re = new RegExp("^"+opts.topic.replace(/([\[\]\?\(\)\\\\$\^\*\.|])/g,"\\$1").replace(/\+/g,"[^/]+").replace(/\/#$/,"(\/.*)?")+"$");
for (var t in retained) {
if (re.test(t)) {
opts.client.send(t,retained[t]);
}
}
return Promise.resolve();
},
/**
* TODO: Unsubscribes a comms connection from a given topic
* @param {Object} opts
* @param {User} opts.user - the user calling the api
* @param {CommsConnection} opts.client - the client connection
* @param {String} opts.topic - the topic to unsubscribe from
* @return {Promise<Object>} - resolves when complete
* @memberof RED.comms
*/
unsubscribe: function(opts) {}
};