centralperk

Manage Complex Work Flow

Code Async JS

Elegantly :)

author Meng G. [email protected]

date 2016-03-21

github https://github.com/gaomeng1900/centralperk

A flow controller based on Subscribe/Publish model and stream model

RequestsJS is required (already in this git , bower install requestsjs to get the updated)

Import in ADM/global way, both supported

centralperk.js contains the flow controler part. browser/node

centralperk.ext.js contains useful http part (get/post/put/delete) packed from requests.js. browser only

对于异步编程，有很多现成的解决方案包括

• ES6 async/Promise
• step.js
• co.js
• then.js
• wind.js
• so on...

但是接口还可以更简洁友好，尤其是处理包含异步编程的复杂任务流程时，step之间应该进一步解耦。

centralperk采用了类似于 publish-subscribe pattern 的方式处理异步回调顺序（事实上，前三个版本都是典型的publish-subscribe pattern），将同步任务和异步任务统一由事件中心管理。支持pipe风格的接口，以及针对十分复杂的逻辑的特殊接口：直接以瀑布流式的字面量定义流程。

实现一个订阅中心进行a->b, a->b&c的管理是容易的（centralperk第一版），但是涉及到多级流程时就要正确处理每次任务触发时所在的flow，并避免多条支线交叉时的引用冲突（第二版），另外还有对性能的优化和对ES6规范的支持（第三版）。

centralperk（v4）的核心在于任务链管理，使用闭包传递一个 stream 变量来标示当前调用/构造所在的flow 以及flow中的位置，来做到flow之间的完全隔离，同时并入重构后的requests.js, 获得更简洁更强大的restful调用接口，并增加了一些新的特性。

实例在test.coffee中。

You may find examples in test.coffee

PS. this manual is long and boring

a example

栗子

Suppose that there a 7 jobs(sync ones and async ones), and you want them excecute in flow like this

What will you do... (ﾟдﾟ)

Before you crash your ⌨

0. sign the functions

# coffeescript

PERK.sign 'task0', (args, done)->
    # do something
    done(args)


PERK.sign 'task1', (args, done)->
	# maybe some XHR
	PERK.get {url:'http://httpbin.org/ip'}， args, done


PERK.sign 'task2', (args, done)->
	# maybe your own async task
	some_async_fun(args, done)
    
# other 4 ones...

前方高~~萌~~能

1. set the stream-like flow

# coffeescript

PERK.stream {
    'task0':
        'task1':
            'task2':
                'task3':{}
        'task4':
            'task5':{}
            'task6':{}
}

2. Here we go!

PERK.task('task0', args)

You can set the flow in gulp.task.pipe way

# coffeescript

PERK.link 'task0' 
    .to 'task1', ['task6', 'task5']
    .to 'task2'
    .to 'task3'

# 0 → 1 → 2 → 3
#     ↓ ↘ 
#     ↘  5 
#       6
  

PERK.stream( { 'task0':{ 'task1':{ 'task2':{} } } } );
// equal to
PERK.link('task0').to('task1').to('task2');
// 0 → 1 → 2

API

sign

• @param taskID {String} : name your task
• @param fun {Function}: the task function
• @return PERK {Object}

• The first one is args(or what ever U call it).

• Read more about Currying [https://en.wikipedia.org/wiki/Currying].

• It will be passed from the previous fun in the flow or from PERK.task('taskName', args);

• Call this function means the end of current function.

• You can pass this done to any other function and call it anywhere you want.

sream

• @param flow {Object/Map}

# coffeescript

PERK.stream {
    'task0':
        'task1':
            'task2':
                'task3':{}
        'task4':
            'task5':{}
            'task6':{}
    'task4':
    	'task7':{}
}
# 0 → 1 → 2 → 3
#   ↘ 
#     4 → 5 → 7
#      ↘ 
#        6
#
# 4 → 7

** important tip **

task

• @param taskName {String}

• @param args {Object}

• Do some task. it will start a flow when this task is at the root of it.

link

• @param taskName {String}

to

• @param taskName {String}

get/post/put/delete

• pack of XHR, based on Requests.js
• see examples and doc of Requests.js [https://github.com/gaomeng1900/requests]