gistfile1.js

/*
 * Current pattern in console code
 * does not leverage the power of promises
 * may as well use callbacks
 */

var _val1;
var _val2;

function apiCall() {
	// some api call
}

apiCall().then(function(data) {
	_val1 = data;
});

// _val2 has implicit dependency on _val1
// if _val1 is not loaded for some totally unrelated reason, this breaks

apiCall(_val1).then(function(data) {
	_val2 = data;
});

doSomeStuff(_val1, _val2);

/*
 * Leveraging promises as representing values
 */

var _val1Promise = apiCall();
// _val2's dependency on _val1 is explicit
var _val2Promise = _val1Promise.then(apiCall);

Promise.all(_val1Promise, _val2Promise).then(function(vals) {
	doSomeStuff(vals[0], vals[1]);
});

_val1Promise.then(function(val1) {
	doAnotherThing(val1);
});

// now I can use val2 without having to worry about whether val1 is loaded
_val2Promise.then(function(val2) {
	doAnotherThing(val2);
});