Simple delta time ticker

Allows setting intervals using delta time for consistency.

Differences from setInterval:

• Tasks can be asynchronous
• Tasks that take longer than the interval won't overlap
• The intervals are more accurate

Examples

Asynchronously count to 5 with 15 millisecond intervals:

var count = 0;
Ticker({ // the `new` keyword is not required
  async: true,
  task: function(next) {
    setTimeout(function() {
      count += 1;
      next();
    }, 10); // task will take 10ms, but the interval will still be 15ms on average
  },
  limit: 5,
  delay: 15,
  stop: function() {
    console.log(count === 5); // verify that there were 5 steps
  }
}).start();

Endless 100 millosecond interval with a synchronous task:

Ticker({
  task: function() { // unlike with the async example, there's no `next` argument
    console.log('on and on…');
  },
  delay: 100
}).start();

Stop a ticker:

var ticker = Ticker({
  task: function() {
    // do something…
  },
  delay: 100
}).start();

setTimeout(function() {
  ticker.stop();
}, 500);

Log the interval between tasks:

var ticker = Ticker({
  task: function(dt) { // the last argument to the task is the delta time
    console.log('%s milliseconds have passed since last task', dt);
  },
  delay: 100
}).start();

Extend the ticker's config after construction:

var ticker = Ticker();

ticker.use({
  task: function() {},
  delay: 10
}).start();

Install

npm install delta-ticker

Test

make test

TODO

• An option to use process.hrtime() (real time) in Node.js
• More accuracy tests and comparisons to setInterval

Notes

• Depends on Date.new and Object.create