eip

Enterprise Integration Patterns for javascript.

This repo is based on jkanschik/node-eip implements various eip patterns for javascript and mainly enhances the aggregator functionality.

Installation

npm install --save eip

Usage

Create a Route

consteip=require('eip');constroute=neweip.Route('Route-0',{route: {retryLimit: 3,retryDelay: 1000},isErrorRoute:false},[])

Add a processor to the Route

route.process(event=>event*2).info()

Inject events to Route

route.inject(1);// output: [2017-03-10 17:04:12.636] [INFO] [aggregator-eip] - [Route-0(info-1)] 2route.inject(2);// output: [2017-03-10 17:04:13.082] [INFO] [aggregator-eip] - [Route-0(info-1)] 4

Builtin Processors

aggregate({ timeout =[1000], maxTimes =3})// oraggregate({ timer=newTimer(), store =newStore(), strategy =newAggregationStrategy()})// Timer, Store and AggregationStrategy are abstract classes exported by eip that can be extended.// see eip-mongo and eip-rabbit for implementations of Timer on top of rabbitmq and Store on top of mongodispatch(route1,route2)filter(event=>event>5);// orfilter(event=>doAsyncStuff(event).then(result=>result>5))// filter can accept conditions tha return a promiseprocess(event=>[event,event])// custom processor that transforms the eventprocess(event=>doAsyncStuff(event))// transform event returning a promisethrottle(10,1000)// 10 events per second (1000 ms)throttleResource({eventsPerPeriod:1,periodInMs:1000})//orthrottleResource({timer: newTimer(),resource: x=>x,pubSub: newPubSub(),queue: newQueue()})// Timer, PubSub and Queue are abstract classes exported by eip that can be extended.// see eip-redis and eip-rabbit for implementations of Timer on top of rabbitmq and pubSub and queue on top of redis//loggingtrace()debug()info()warn()error()fatal()// all logger scan transform the logging msg using a callback// eg:event=>'message to be logged:'+event;

Aggregator example

constaggregator=neweip.Route().aggregate({timeout: [1000],maxTimes: 3}).info();aggregator.inject({headers: {id: 'the id to aggregate data',param: 'one'},body:'one'});aggregator.inject({headers: {id: 'the id to aggregate data',param: 'two'},body:'two'});aggregator.inject({headers: {id: 'the id to aggregate data',anotherParam: 'other'},body:'three'});// it will be aggregated and log to output:// [2017-03-10 16:32:07.605] [INFO] [aggregator-eip] - [Route-1(info-1)] {"body":["one","two","three"],"headers":{"status":"COMPLETED","id":"the id to aggregate data","param":"two","anotherParam":"other","aggregationNum":1,"timeoutNum":0,"previousStatus":"INITIAL"}}// [2017-03-10 16:32:08.606] [DEBUG] [aggregator-eip] - [Route-1(aggregate-0)] [timeout-1] [1] Already completed// we could have formatted the output using:aggregator.info(aggregated=>JSON.stringify(aggregated,null,2));/*[2017-03-10 16:38:05.484] [INFO] [aggregator-eip] - [Route-1(info-2)] { "body": [ "one", "two", "three" ], "headers": { "status": "COMPLETED", "id": "the id to aggregate data", "param": "two", "anotherParam": "other", "aggregationNum": 1, "timeoutNum": 0, "previousStatus": "INITIAL" }}[2017-03-10 16:38:06.152] [DEBUG] [aggregator-eip] - [Route-1(aggregate-0)] [timeout-1] [the id to aggregate data] Already completed*/

License

MIT