smoop v0.0.2

The Smooth Operator

Cache the return value of an asynchronous function (callback-taking or promise-returning).

Optional: have it periodically refresh data in the background, and keep returning the latest until a new value replaces it. Especially useful with unreliable or slow sources.

smoop(fn, opts) -> fn'

Options

• refresh

  	Milliseconds before proactively trying to fetch a new value. The current value
  	is kept and handed out until replaced.
  
  	Without `refresh` you will get a **lazy behavior** where a new
  	value is fetched only when needed.
  
  	With `refresh` a value will initially be polled.

• maxAge

  	Milliseconds until a value is discarded.
  
  	If you do not set `maxAge` you are guaranteed to always get a value if any
  	source has ever resolved.
  
  	A `maxAge` of zero is the same as disabling the caching altogether.

• name

  	Smooth operator uses [debug](https://github.com/visionmedia/debug) and
  	assigns each operator a sequential number for referencing. `name` allows
  	you to use your own reference.

Using node-style callbacks

var smoop = require('smoop');
var dns = require('dns');

var googleIp = smoop(function( cb ){
	dns.lookup('google.com', cb);
}, {
	refresh: 60000,	// fetch each minute
});

googleIp(function( err, result ){
	console.log('google.com address:', result[0]);
});

Using promises

var Promise = require('bluebird');
var smoop = require('smoop');
var dns = Promise.promisifyAll(require('dns'));

var googleIp = smoop(function(){
	return dns.lookupAsync('google.com');
}, {
	refresh: 60000,	// fetch each minute
});

googleIp().spread(function( ip ){
	console.log('google.com address:', ip);
});