vytronics.hmi/lib/project.js

Vytronics HMI server. Core components Vytronics HMI - The 100% Free, Open-Source, SCADA/HMI Initiative

/*
Copyright 2014 Charles Weissman

This file is part of "Vytroncs HMI, the 100% Free, Open-Source SCADA/HMI Initiative"
herein referred to as "Vytronics HMI".

Vytronics HMI is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Vytronics HMI is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with Vytronics HMI.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
Project module

Loads project.yml file to define the db module global vars.

*/
var path = require('path');

var vy_yaml = require('./vy.yaml');
var vyutil = require('./vyutil');
var db = require('./db');
var log = require('log4js').getLogger('project');
log.setLevel(vyutil.getenv('VYTRONICS_PROJECT_LOG_LEVEL', 'warn'));

exports.version = '0.0.0';

//Load the project.yml file into db vars.

db.serverdb = require('./serverdb');

db.tagdb = require('./tagdb');

db.driverdb = require('./driverdb');

db.clientdb = require('./clientdb');

db.rpcdb = require('./rpcdb');



//Load the project from json file
var load = function(projectdir, callback) {

    db.projectdir = path.resolve(__dirname,projectdir);
    var file = path.resolve(db.projectdir, "./project.yml");

	//TODO - unload any existing project?
	
	log.info("Loading project " + file);
	try {

		var err = undefined;
		
        vy_yaml.load(file, function (error, json){
            
            if (error) {
                log.error('error loading project.yaml - ' + error.stack || error.message || 
                             String(error));
                err = error.message;
            }
            else {
            
                //load server vars
                db.serverdb.load(json.server);

                //load driverdb
                db.driverdb.load(json.drivers, db.projectdir);

                //load tagdb and create system tags
                db.tagdb.load(json.tags);

                //Link up drivers
                var tags = db.tagdb.getTags();
                tags.forEach( function(tid) {
                    var tag = db.tagdb.getTag(tid);

                    if(tag.driverinfo) {
                        db.driverdb.subscribe(tag.id, tag.driverinfo);
                    }

                    //Otherwise this is an in memory tag

                });

                //Start drivers
                db.driverdb.emitter.on("drivervalue", function(driverid, tags, value, item) {
                    //Note that item param is not really needed. Just included for debug and
                    //may get rid of it all together
                    tags.forEach( function(tagid) {
                        var tag = db.tagdb.getTag(tagid);
                        tag.setValue(value);
                    });
                });
                db.driverdb.start();

                //Kick off any periodic calculations
                //TODO - call tagdb method?
                db.tagdb.start();
            }
            
            if (vyutil.isFunction(callback)){
                callback(err);
            }
	   });
    }
	catch(err) {
		log.fatal("Exception loading project. Err:" + err);
		log.fatal(err.stack);
        process.exit(1);
	}
};

var applicationCall = function(name, data) {
	
	//Try to find function name
	var appCalls = db.applicationCalls;
	if ( appCalls.hasOwnProperty(name)) {
		
		try {
			var result = appCalls[name](data);
			return {result:result,err:undefined};
		}
		catch(err) {
			return{result:undefined,err:"Error: Application call failed - " + err.message};
		}        
	}
	return {result:undefined, err:"Error: Application call ["+name+"] not found."};

};
	
//Export the public stuff
module.exports.load = load;