Callback once

callback-once

var sampleCallback = function(arg1) {
        console.log('callback fired: %s.', arg1)
}

var CallbackOnce = function(callback) {
        this.isFired = false
        this.callback = callback
}

CallbackOnce.prototype.create = function() {
        var delegate = this

        return function() {
                if(delegate.isFired)
                        return

                delegate.isFired = true
                delegate.callback.apply(null, arguments)
        }
}

obj1 = new CallbackOnce(sampleCallback)
var aa = obj1.create()

setTimeout(function() {
        aa('a')
}, 200)
setTimeout(function() {
        aa('b')
}, 500)