[jQuery] created an $.interval function for polling, but it needs some cleanup I think
I wanted to be able to do polling using a function like this:
$.interval(seconds, callbackFunction);
The interval function will perform the callbackFunction every x
seconds, unless the previous call is still executing (inspired from
Prototype's PeriodicalExecuter)
I have written one that works, but as I have still a bit green with
javascript I know it can be improved.
Here is what I've got:
/*
* interval
* by Steven Wicklund <swicklund@pobox.com>
* A setInterval wrapper for jQuery
* So this works for 1 timer interval, but the currentlyExecuting
singleton will likely cause issues
* if there is more than one interval per page...
*/
jQuery.extend( {
interval:function(frequency, fn) {
this.currentlyExecuting = false;
setInterval(function() {$.onTimerEvent(fn);}, frequency * 1000);
},
/*
* onTimerEvent courtesy Prototype PeriodicalExecuter()
* (c) 2005 Sam Stephenson <sam@conio.net>
* (MIT license see: http://prototype.conio.net/)
*/
onTimerEvent: function(callback) {
if (!this.currentlyExecuting) {
try {
this.currentlyExecuting = true;
callback();
} finally {
this.currentlyExecuting = false;
}
}
}
});