freeboard.js

/**
 * Copyright 2015 Urbiworx
 *
 * 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.
 **/
var express=require("express");
var mustache=require("mustache");
var fs=require("fs");
var bodyParser = require('body-parser')
module.exports = function(RED) {
    "use strict";
	var userDir="";
	if (RED.settings.userDir){
		userDir=RED.settings.userDir+"/";
	}

	var dstemplate;
	var dslib;
	var pendingresponses=new Array();
	fs.readFile(__dirname+"/datasource.template", function (err, data) {
		if (err) throw err;
		dstemplate=data.toString();
	});
	fs.readFile(__dirname+"/datasource.jsheader", function (err, data) {
		if (err) throw err;
		dslib=data.toString();
	});

	var nodes=new Array();
    function Freeboard(n) {
        RED.nodes.createNode(this,n);
        this.name = n.name.trim();
		nodes.push(this);
        var that = this;
        this.on("input", function(msg) {
			that.lastValue=msg.payload;
			postValue(that.id,that.lastValue);
        });
		this.on("close",function() {
			var index = nodes.indexOf(that);
			if (index > -1) {
				nodes.splice(index, 1);
			}
		});
    }

	function postValue(id,value){
		var resp=pendingresponses;
		pendingresponses=new Array();
		for (var i in resp){
			var ret={};
			ret[id]=value
			resp[i].end(JSON.stringify(ret));
		}
	}

	function interval(){
		var resp=pendingresponses;
		pendingresponses=new Array();
		for (var i in resp){
			resp[i].end(JSON.stringify({}));
		}
	}
	setInterval(interval,60000);


	RED.httpNode.use(bodyParser.urlencoded({
		extended: true
	}));
	RED.httpNode.use("/freeboard",express.static(__dirname + '/node_modules/freeboard'));
	RED.httpNode.get("/freeboard_api/datasources",
		function (req,res){
			res.write(dslib);
			for (var i in nodes){
				res.write(mustache.render(dstemplate,{name:nodes[i].name,display_name:nodes[i].name,description:'',id:nodes[i].id}));
			}
			res.end();
		}
	);
	RED.httpNode.post("/freeboard_api/dashboard",
		function (req,res){
			fs.writeFile(userDir+"freeboard_"+req.body.name+".json", req.body.content, function (err, data) {
				if (err) throw err;
				res.end();
			});

		}
	);
	RED.httpNode.get("/freeboard_api/datasourceupdate",
		function (req,res){
			if(req.param("direct",false)){
				var ret={};
				for (var i in nodes){
					ret[nodes[i].id]=nodes[i].lastValue;
				}
				res.end(JSON.stringify(ret));
			} else {
				pendingresponses.push(res);
			}
		}
	);
	RED.httpNode.get("/freeboard_api/dashboard/:name",
		function (req,res){
			fs.readFile(userDir+"freeboard_"+req.params.name+".json", function (err, data) {
				if (err) {
					res.end(JSON.stringify({empty:true}));
				} else {
					res.end(data.toString());
				}
			});

		}
	);
    RED.nodes.registerType("freeboard",Freeboard);
}