app.js

/*******************************
	WS2812 LED Control
		A tiny, primitive app for controlling WS2812 LEDs.

	Austin Brown - 2017
	http://luxdvie.github.io
	austin@brogencreations.com

	LICENSE
	
	The MIT License (MIT)

	Copyright (c) 2017  Austin Brown

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:
	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	THE SOFTWARE.
*******************************/
	
	/* Common Libraries & Setup */
	var express = require('express');
	var app = express();
	var bodyParser = require('body-parser');
	var path = require("path");
	app.use(express.static(__dirname + '/public'));
	app.use(bodyParser.json());
	app.use(bodyParser.urlencoded({ extended: true }));

	/* The port the server will listen on */
	var HTTP_PORT = 81;

	/* Global reference to the LED strip */
	var strip = require("./strip.js");

	/*  Animation Libraries */
	var xmas = require("./animations/xmas.js");
	var fade = require("./animations/fade.js");
	var rainbow = require("./animations/rainbow.js");
	var control = require("./animations/control.js");
	var fixed = require("./animations/fixed.js");


/*******************************
	web methods
*******************************/

	/*
	*	Generic handler for an animation request.
	*
	*		All requests should be in the format
	*		
	*			lib => name of animation package you're referencing
	*			method => name of method in package you're calling
	*			args => object containing any arguments you want to pass to the animation method
	*
	*/
	app.post('/AnimationRequest', function (request, response) {
		response.header("Access-Control-Allow-Origin", "*");

		var lib = request.body.hasOwnProperty("lib") ? request.body.lib : "";
		var instance = GetLibraryInstance(lib);
		if (instance === null || typeof instance === "undefined") { response.send("Library not found."); return; }
		
		var method = request.body.hasOwnProperty("method") ? request.body.method : null;
		if (method === null) { response.send("Method not found."); return; }

		var args = request.body.hasOwnProperty("args") ? request.body.args : "";

		var rsp = instance[method](args, strip);

		response.send(rsp);
	});

	/*
	*	Home
	*/
	app.get('/', function (req, res) {
		res.header("Access-Control-Allow-Origin", "*");
		res.sendFile(path.join(__dirname + '/app.html'));
	});


/*******************************
	common
*******************************/

	/* 
	*	Find the correct reference to a specific library name;
	*/
	function GetLibraryInstance(key) {
		var lib = null;
		switch (key) 
		{
			case "xmas":
				lib = xmas;
			break;
			case "fade":
				lib = fade;
			break;
			case "rainbow":
				lib = rainbow;
			break;
			case "control":
				lib = control;
			break;
			case "fixed":
				lib = fixed;
			break;
		}

		return lib;
	}

/*******************************
	startup
*******************************/

	var server = app.listen(HTTP_PORT, function() {
		console.log('***************************');	
		console.log(' WS2812 CONTROLLER STARTUP ');	
		console.log('***************************');	
	});