can-event/async/async

Makes the event system asynchronous. WARNING: This is experimental technology.

`Object`

The can-event/async/async module makes the event system asynchronous. It:

Provides an async method which converts event binding and dispatching to happen asynchronously.
Provides sync method which converts event binding and dispatching to happen synchronously.
Provides an asynchronous dispatch, queue, [can-event/async/async.addEventListener] and [can-event/async/async.removeEventListener].
Provides a flush which can be used to immediately run all tasks in the task queue.

Use

Use can-event/async/async's async method to make event binding and dispatching happen immediately following the current event loop.

var canEvent = require("can-event");
var canAsync = require("can-event/async/async");
canAsync.async();

var obj = {};
Object.assign(obj, canEvent);

obj.addEventListener("foo", function(){
  console.log("heard foo");
});
obj.dispatch("foo");
console.log("dispatched foo");

// Logs -> "dispatched foo" then "heard foo"

This means you never have to call start and stop. Notice that in the following example "change" is only fired once:

var canAsync = require("can-event/async/async");
canAsync.async();

var compute = require("can-compute");

var first = compute("Justin");
var last = compute("Meyer");

var fullName = compute(function(){
    return first() + " " + last();
});

fullName.on("change", function(ev, newVal, oldVal){
    newVal //-> "Payal Shah"
    oldVal //-> "Justin Meyer"
});

first("Payal");
last("Shah");