willkan/event-pipe

a simple event pipe, make async easy to use.

EventPipe

An simple tool to code with event like a pipe.

Sequence

var ep = require('event-pipe');
ep(function(url){ // request an url
	request(url, this)
}, function(err, body){ // request done, write file
	if (err) {
		throw err;
	}
	var file = __dirname + '/google.html';
	fs.writeFile(file, body, this);
}, function(err){ // write file done
	if (err) {
		throw err;
	}
	console.log('done');
}).run('http://www.google.com/') // start pipe

var ep = require('event-pipe');
var p = ep();
p.seq(step1, step2, step3).seq(step4).run(args)

Parallel

var ep = require('event-pipe');
ep.on('drain', function(){
	console.log('all done');
})
ep([function(){
	fs.writeFile('a.file', 'somedata', this);
}, function(){
	fs.writeFile('b.file', 'somedata', this);
}, function(){
	fs.writeFile('c.file', 'somedata', this);
}]).run();

var ep = require('event-pipe');
var p = ep();
p.par(step1_action1, step1_action2, step1_action3).par(step2_action1, step2_action2).run(args)

Mixed

var ep = require('event-pipe');
ep(function(url){ // request an url
	request(url, this)
}, [ // request done, parallel write file
	function(err, body){ // file1
		if (err) {
			throw err;
		}
		var file = __dirname + '/google1.html';
		fs.writeFile(file, body, this);
	},
	function(err, body){ // file2
		if (err) {
			throw err;
		}
		var file = __dirname + '/google2.html';
		fs.writeFile(file, body, this);
	},
], function(err){ // write file done
	console.log('all done');
}).run('http://www.google.com/') // start pipe

var ep = require('event-pipe');
var p = ep();
p.add(step1, [step2_action1, step2_action2], step3).run(args)

Lazy mode

var ep = require('event-pipe');
var e = ep().on('error', function(err){
	console.error('got error:', err.stack);
}).lazy(function(url){ // request an url
	request(url, this)
}).lazy([
	function(body){ // file1
		var file = __dirname + '/google1.html';
		fs.writeFile(file, body, this);
	},
	function(body){ // file2
		var file = __dirname + '/google2.html';
		fs.writeFile(file, body, this);
	},
]).lazy(function(){ // write file done
	console.log('all done');
}).run('http://www.google.com/') // start pipe

var ep = require('event-pipe');
var p = ep();
p.lseq(step1, step2, step3).run(args)
p.lpar(step1, step2, step3).run(args)

stop

var ep = require('event-pipe');
var p = ep();
p.add(step1, step2, function(stop){ // step3, step4 will never be run
	if (stop) {
		this.__stop()
	}
},step3, stop4).seq(step4).run(args)

var ep = require('event-pipe');
var p = ep();
p.add(step1, step2, step3, stop4).seq(step4).run(args).stop() // step2, step3, step4 will never be run

Events

error

got error when use lazy mode.

stop

stop start.

stopped

pipe stopped.

drain

no more events.