collect-callbacks

Aggregate many event emissions into one

Aggregate many callbacks into one

var collect = require('collect-callbacks');

collect.all( function(aggregate) {
    setTimeout(aggregate(function(){ console.log("two") }),2000);
    setTimeout(aggregate(function(){ console.log("three") }),3000);
})(function (error, args) {
    // This won't execute until both of the timeouts above have completed
});

collect.all( function(aggregate) {
    setImmediate(aggregate(),'test','this');
    setImmediate(aggregate(),1,2,3);
})(function (error, args) {
    // args is an an array of arguments objects, the first with
    // ['test,'this'] and the second with [1,2,3]
});

collect.any( function(aggregate) {
    setTimeout(aggregate(function(){ console.log("two") }),2000);
    setTimeout(aggregate(function(){ console.log("three") }),3000);
})(function (error, args) {
    // This will be called as soon as the shorter timer triggers.
    // Note that the longer one will still trigger, just after this is executed.
});

Reduce a group of unrelated callbacks into a single callback. Either when the first event is emitted, or after all callbacks have been emitted at least once.

var collect = require('collect-callbacks');

  • collect.all( setup[, alldone] )[ -> promisable]

setup is a function with a signature of (event) that should setup whatever event listeners you want to be aggregated into the collection. The event argument is a function with a signature of ([listener]) that you should call to generate event handlers that will be part of this aggregation. You can optionally pass through your usual callback function in the listener argument.

collect.all will call alldone (if passed) and fullfill the promisable when ALL of the callbacks associated with it have triggered at least once.

The promisable is resolved with the arguments of all of the callbacks it collected.

  • collect.any( setup[, alldone] )[ -> promisable]

Like collect.all but it triggers on the first of any of the aggregated callbacks to complete.

See https://www.npmjs.org/package/promisable

In short, they're compatible with Promises/A+ but they're also functions that you can pass a callback that will be called in the usual node fashion of (error, result).

https://metacpan.org/pod/AnyEvent::Collect