- Eventchain is a module to call the callbacks on same event one after one.
- Just like the series feature in async module, but it's powered by node built-in module "EventEmitter".
- For better code structure, more maintainable.
npm install eventchain
var Eventchain = require('eventchain');
var ec = Eventchain.create('after save');
// if do not declare a name, it will create a run-once eventchain with a random name.
// eg: var ec-only-once = Eventchain.create();
ec.add(function (record, next) {
...
// pass the default arguments to the next event.
next();
// pass an error to top callback.
next(new Error('...'));
// pass the new argument to the next event, replace of the default.
record.id = 'xxx';
next(null, record);
});
ec.add(anotherCallback);
ec.add(anotherCallback);
// emit, should be given two arguments.
// the first is an args which will pass to the first event in the chain.
// the second is the top callback, which will handle error if event pass back to it, or fire after all the events executed.
ec.emit(args, function (e) {
...
});
// if ec is done and no useful any more. remember to clear it.
// run-once eventchain will clear itself automatically.
ec.clear();more detail, please see the example files.