query-chainer.js
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var Utils = require("./utils")
var QueryChainer = module.exports = function(emitters) {
var self = this
this.finishedEmits = 0
this.emitters = []
this.fails = []
this.finished = false
this.runned = false
this.eventEmitter = null
emitters = emitters || []
emitters.forEach(function(emitter) { self.add(emitter) })
}
Utils.addEventEmitter(QueryChainer)
QueryChainer.prototype.add = function(emitter) {
this.observeEmitter(emitter)
this.emitters.push(emitter)
return this
}
QueryChainer.prototype.observeEmitter = function(emitter) {
var self = this
emitter
.on('success', function(){
self.finishedEmits++
self.finish()
})
.on('failure', function(err){
self.finishedEmits++
self.fails.push(err)
self.finish()
})
}
QueryChainer.prototype.finish = function(result) {
this.finished = (this.finishedEmits == this.emitters.length)
if(this.finished && this.runned) {
var status = this.fails.length == 0 ? 'success' : 'failure'
result = this.fails.length == 0 ? result : this.fails
this.eventEmitter.emit(status, result)
}
}
QueryChainer.prototype.run = function() {
var self = this
this.eventEmitter = new Utils.CustomEventEmitter(function() {
self.runned = true
self.finish()
})
return this.eventEmitter.run()
}