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collect-callbacks

collect-callbacks

Aggregate many callbacks into one

Synopsis

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

collect.all( function(aggregate) {
    setTimeout(aggregate(function(){ console.log("two") }),2000);
    setTimeout(aggregate(function(){ console.log("three") }),3000);
}, function (err, 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 (err, args) {
    // args is an an array of arguments objects, the first with
    // ['test,'this'] and the second with [1,2,3]
});

collect.all( function(aggregate) {
    setImmediate(aggregate(),'test','this');
    setImmediate(aggregate(),1,2,3);
}.then(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 (err, 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.
});

Description

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.

Functions

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

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

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 Promise when ALL of the callbacks associated with it have triggered at least once.

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

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

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

Prior Art

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