PromiseChain

Light weight javascript library to handle promises control structures with ease.

This library is about structure control mechanisms to handle promises, like if/else, or while.

It work with a inside scope to save all the results of the multiple promises you can launch.

How to use

The following example run multiple promises waiting until the end of the previous.

PromiseChain = require('PromiseChain.js');   // Not necesary in client version

var dwarf = {
	gold:3,
	money:0,
	digSomeGold: function(scope){
		var me = this;
		return new Promise(function(resolve, reject) { setTimeout(function(){
			var goldExtracted = Math.floor(Math.random() * 4);
			me.gold += goldExtracted;
			console.log(me);
			console.log("I got "+goldExtracted+" gold");
		 	resolve(goldExtracted);
		} , 1000);});
	},
	askPermisionToSell: function(scope){
		var me = this;
		return new Promise(function(resolve, reject) { setTimeout(function(){

		 	resolve(true);
		
		} , 1000);});
	},
	sellGold: function(scope){
		var me = this;
		return new Promise(function(resolve, reject) { 	setTimeout(function(){
		 	  	me.gold -= 1;
		 	  	me.money += 100;
		 	  	console.log(me);
		 	  	resolve(me.gold);
		 	 } , 1000); 	
		 });
	},
	hasPermision: function(scope){
		var me = this;
		return scope.permision === true;
	},
	hasGold: function(scope){
		var me = this;
		console.log("hasGold" + me.gold);
		return me.gold > 0 ;
	},
	countMoney: function(scope){
		var me = this;
		return new Promise(function(resolve, reject) { 
	 	  	setTimeout(function(){
				console.log("you have earned "+ me.money +" of money");
				console.log(scope);
	 	  		resolve(me.money);
	 	  	} , 1000); 	
	 	});
	}
}



new PromiseChain({},dwarf)
	.continue(dwarf.digSomeGold,"fisrtMiningDone")
	.continue(dwarf.digSomeGold,"secondMiningDone")
	.continue(dwarf.askPermisionToSell,"permision")
	.ifElse(dwarf.hasPermision,function(sc){
		return new PromiseChain(sc,dwarf)	
			.while(dwarf.hasGold, dwarf.sellGold ,'whileResults') // results are stored in an array in the scope if no need you can omit the parameter
		.end();	
	},function(sc){return 'go sell your dirty gold anywhere else!';},'ifelseResult')
	.continue(dwarf.countMoney)
.end();