Pauseable
Pauseable allows you to pause event emitters, timeouts, and intervals. It can easily group multiple of these pauseable objects and pause entire groups.
Usage
Using pauseable with EventEmitter
var pauseable = require('pauseable')
, EventEmitter = require('events').EventEmitter
;
var ee = new EventEmitter();
ee.on('foo', function() { ... });
pauseable.pause(ee);
ee.emit('foo', 'hellow');
pauseable.resume(ee);
Comes with pauseable setTimeout and setInterval too
var timeout = pauseable.setTimeout(function() {
}, 5000);
setTimeout(function() {
timeout.pause();
timeout.isPaused();
setTimeout(function() {
timeout.resume();
}, 3000);
}, 2000);
The function
and ms
arguments are interchangeable. Use whichever way you prefer!
var interval = pauseable.setInterval(5000, function() {
interval.pause(2000);
});
Grouping
var g = pauseable.createGroup();
var ee1 = g.add(new EventEmitter());
var ee2 = g.add(new EventEmitter());
ee1.on('forth', function() {
g.pause(500);
console.log('forth');
ee2.emit('back');
});
ee2.on('back', function() {
console.log('back');
ee1.emit('forth');
});
var timeout = g.setTimeout(function() {
ee2.emit('back', 'poop');
}, 1000);
Motive
Javascript is event based by nature. When developing large scale applications that are completely event based, it becomes complicated to pause the streaming of events, because Javascript never "sleeps". It becomes even more complicated to pause timeouts and intervals having to keep track of when they were paused so they can be resumed with the correct time again.
That's where this module comes in. Pauseable helps manage pausing and resuming your application or part of it. It works with EventEmitter and with setInterval and setTimeout.
API
Events
pauseable.pause(ee, [ms])
Pauses an instance of EventEmitter. All events get buffered and emitted once the emitter is resumed. Currently only works with EventEmitters. Optional ms
will pause only for that long.
pauseable.resume(ee, [ms])
Resumes the emitter. Events can be emitted again. Optional ms
will resume only for that long.
Timers
pauseable.setTimeout(fn, ms) and pauseable.setInterval(fn, ms)
Creates a pauseable timeout or interval. fn
and ms
are interchangeabale. Returns an instance of timer.
timer.pause([ms])
Pauses timer. Optional ms
will pause the timer only for that amount.
timer.resume([ms])
Resumes timer. Optional ms
will resume the timer only for that amount.
timer.next()
Returns the number of ms left until the fn
function in the constructor gets called again.
timer.clear()
Clears timeout. Can no longer be resumed.
timer.isPaused()
Returns true
if timer is currently paused.
timer.isDone()
Returns true
if timer was a timeout and fn
was called, or timer.clear()
has been called.
timer.onDone(callback)
If timer is a timeout, this can be used to execute the callback
when the fn
in the constructor is called.
Groups
pauseable.createGroup()
Creates a group
where emitters and timers can be easily managed.
group.add()
Add an emitter or a timer to the group. Returns added emitter/timer.
group.setTimeout(fn, ms)
group.setInterval(fn, ms)
Shortcut to create an instance of a timer and add it to the group.
group.pause([ms])
Pauses all emitters and timers in the group.
group.resume([ms])
Resumes all emitters and timers in the group.
group.clear()
Clears timers in the group.
group.isPaused()
Returns true
is group is paused.
group.isDone()
Returns true
if all timers currently in the group are timeouts and their original function has been called or all timers have been cleared.
group.timers()
Contains both emitters and timers. Useful if you want to micro manage more.
Install
npm install pauseable
Tests
Tests are written with mocha
npm test
License
MIT