Nils Wloka nilswloka

This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.

You're Missing the Point of Promises

Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:

getTweetsFor("domenic", function (err, results) {
 // the rest of your code goes here.

	Disclaimer: The instructions are the collective efforts from a few places online.
	Nothing here is my original. But I want to put them together in one place to save people from spending the same time as I did.

	First off, bundle.
	==================

	1. cd to the project directory
	2. Start the react-native packager if not started
	3. Download the bundle to the asset folder:
	curl "http://localhost:8081/index.android.bundle?platform=android" -o "android/app/src/main/assets/index.android.bundle"

	(ns foobar.components
	(:require [com.stuartsierra.component :as component]
	[compojure.api.sweet :refer :all]))

	(defmethod compojure.api.meta/restructure-param :components
	[_ components acc]
	(update-in acc [:letks] into [components `(::components ~'+compojure-api-request+)]))

	(defn wrap-components [handler components]
	(fn [req]

	(ns hammock-cafe.ui.history
	(:require [io.pedestal.app.protocols :as p]
	[io.pedestal.app.util.log :as log]
	[io.pedestal.app.messages :as msg]))

	(def last-page (atom nil))

	(def dispatchers (atom {}))

	(defn navigate [token]

	<html>
	<head>
	<title>Flapjax Demo: Time 1</title>
	</head>
	<p>The time is <span class="fixedBlock"><span id="timer">not initialized</span></span>.</p>
	<p>The time in seconds is <span class="fixedBlock"><span id="timer2">not initialized</span></span>.</p>
	<script type="text/javascript" src="main.js"></script>
	</body>
	</html>

	var mod = {};

	mod.AuthCtrl = [
	'$scope', 'requests401', '$http', 'Ping', '$location', function($scope, requests401, $http, Ping, $location) {
	var fadespeed = 300;

	$scope.user = {
	"username": "test",
	"password": "test"
	};

	;; borrowed from ibdknox/jayq
	(defn map->js [m]
	(let [out (js-obj)]
	(doseq [[k v] m]
	(aset out (name k) v))
	out))

	(defn clj->js
	"Recursively transforms ClojureScript maps into Javascript objects,
	other ClojureScript colls into JavaScript arrays, and ClojureScript

	/**
	* @license Angular Auth
	* (c) 2012 Witold Szczerba
	* License: MIT
	*/
	angular.module('angular-auth', [])

	/**
	* Holds all the requests which failed due to 401 response,
	* so they can be re-requested in the future, once login is completed.

	; A REPL-based, annotated Seesaw tutorial
	; Please visit https://github.com/daveray/seesaw for more info
	;
	; This is a very basic intro to Seesaw, a Clojure UI toolkit. It covers
	; Seesaw's basic features and philosophy, but only scratches the surface
	; of what's available. It only assumes knowledge of Clojure. No Swing or
	; Java experience is needed.
	;
	; This material was first presented in a talk at @CraftsmanGuild in
	; Ann Arbor, MI.

	(ns evolvefn) ;; Lee Spector ([email protected]) 20111018

	;; This code defines and runs a genetic programming system on the problem
	;; of finding a function that fits a particular set of [x y] pairs.

	;; The aim here is mostly to demonstrate how genetic programming can be
	;; implemented in Clojure simply and clearly, and several things are
	;; done in somewhat inefficient and/or non-standard ways. But this should
	;; provide a reasonable starting point for developing more efficient/
	;; standard/capable systems.