audiot-node-job-manager/lib/crontab_manager.js

A wrapper Object for node-cron that allows you to manage multiple cron jobs at once.

/**
* crontabmanager.js - post callbacks to cronjobs 
* - create, update, delete cronjobs via the net
* please see https://github.com/ncb000gt/node-cron and http://crontab.org/ for crontab info 
* Synopsis:
*  var CronTabManager = require('crontab_manager'),
*  myCrontTabManager = new CronTab(key, '* 2/2 13-16 * *', function, options  ) // or
*  myCrontTabManager = new CronTab()
* in the first form, a new job is created on key 'key' with onTick set to 'function', cronTime is set to '* 2/2 13-16 * *', and options can include stuff like start, onComplete, and timeZone
* the second form just a new manager is created to which you can add jobs. Remember jobs do not start automatically, you have to set options to {start: true} or call start() after the job is created.
*
* Other methods include:
*  myCrontTabManager.update(key, newCronString) //or
*  myCrontTabManager.upadte(key, tabOrfunction) // or
*  myCrontTabManager.update(key, tab,function)
*  myCrontTabManager.stop(key)
*  myCrontTabManager.start(key)
*  myCrontTabManager.deleteJob(key)
*  myCrontTabManager.add(key, cronString, function, options)
*
* currently you cannot set context for any job.
*/

var CronJob = require('cron').CronJob;
function CrontabManager(key,tab, task, options) {
	this.jobs = {};
	if (key && tab && task)
		this.add(key, tab,task,options);
	
}

CrontabManager.prototype.add = function(key, tab, task, options) {
   options = combineOptions(tab, task, options);
   try {
   	   if (this.jobs[key]) {
   	   	   this.deleteJob(key);
   	   	   console.warn(key + " already existed and was deleted from the manager...");
   	   }
	this.jobs[key] = new CronJob(options);
   } catch(fooBaredByUser) {
   	console.error("crontab: " + tab + " possibly not valid, job " + key + " not started..." + fooBaredByUser.message  ); 
   }

}

CrontabManager.prototype.update = function() {
	if (arguments.length === 2) {
		//console.log("arguments are 2 units long." )
		//console.log(arguments)
		if (typeof arguments[1] === 'string')
			updateTab.call(this, arguments[0], arguments[1]);
		else if (arguments[1] instanceof Function)
			updateTask.call(this,  arguments[0], arguments[1]);
	} else if (arguments.length === 3) {
		updateTab.call(this, arguments[0], arguments[1])
		updateTask.call(this,  arguments[0], arguments[2])
	} else 
		console.error("incorrect number of arguents passed to update.. won't update.. " + arguments[0]);
}

CrontabManager.prototype.deleteJob = function(key) {
	try {
		this.jobs[key].stop();
		delete this.jobs[key];
	} catch (err) { console.error("error in trying to stop job: " + key + ": " + err) }
}

CrontabManager.prototype.start = function(key) {
	try {
		if (this.jobs[key].running)
			console.warn(key + " job already running");
		else 
			this.jobs[key].start();	
	}catch (err) {
		console.error("couldn't start job: " + key + ": " + err);
	}
}

CrontabManager.prototype.stop = function(key) {
	try {
		if (! this.jobs[key].running )
			console.warn(key + " job already stopped");
		else 
			this.jobs[key].stop();
		
	}
	catch(err) {
		console.error("couldn't stop job: " + key + ": " + err)
	}
}

CrontabManager.prototype.stopAll = function() {
	for (jobKey in this.jobs) {
		try {
			this.jobs[jobKey].stop()	
		}catch(err) {
		
		}
	}
}

CrontabManager.prototype.toString = function() {
	var manString = "{\n";
	for (jobKey in this.jobs) {
		
	  manString += "'" + jobKey + "': " + this.jobs[jobKey].cronTime.source + ": " + this.jobs[jobKey]._callbacks[0] +  ": " + (this.jobs[jobKey].running ? "Running" : "Stopped")
	}
	manString += "\n}";
	return manString;
}

CrontabManager.prototype.listCrons = function() {
	var manString = "{\n";
	for (jobKey in this.jobs) {
		manString += "'" + jobKey + "': " + this.jobs[jobKey].cronTime.source + " status: " + (this.jobs[jobKey].running ? "Running" : "Stopped") + "\n";
	}                                                               
	manString += "\n}";
	return manString;
}

CrontabManager.prototype.exists = function(tabKey) {
	if (this.jobs[tabKey]) 
		return true;
	return false;
}

function combineOptions(tab, task, options) {
	var newOpts = {};
	newOpts.cronTime = tab; newOpts.onTick = task
	
	if (options instanceof Object) {
		// might overwrite... please be careful.
		for (optionKey in options)
			newOpts[optionKey] = options[optionKey];
	}
	return newOpts;
}

function updateTab(key, cronstring) {
	
	try {
		var running = this.jobs[key].running;
	  this.jobs[key].stop()
	
	 
	  	  this.jobs[key] =  new CronJob(cronstring, this.jobs[key]._callbacks[0], this.jobs[key].onComplete, running, this.jobs[key].zone)
	  
	} catch (tabErr) {
		console.error("error updating tab: " + key + " " + tabErr.message);
	}
}

function updateTask(key, task) {
	try {
	var running = this.jobs[key].running;
	  this.jobs[key].stop()
	  
	  if ( ! ( task instanceof Function) ) {
	  	  console.error("can't update with something that is not a function: " + typeof(task))
	  	  return
	  }
	 
	  	  this.jobs[key] =  new CronJob(this.jobs[key].cronTime.source, task, this.jobs[key].onComplete, running, this.jobs[key].zone)
	
	  	 
	} catch (tabErr) {
		console.error("error updating task: " + key + " " + tabErr.message);
	}
}

module.exports = CrontabManager;