I've subbed my implementation with your to do some use-case testing. I'll
report back anything of interest as I go along.
Rick
On Wed, Jun 24, 2009 at 10:49 AM, Rick Waldron <waldron.r...@gmail.com>wrote:
> This is fantastic feedback - thanks!
>
>
>
>
>
>
> On Wed, Jun 24, 2009 at 9:55 AM, Robert Kieffer <bro...@gmail.com> wrote:
>
>>
>> I can't say I'm a big fan of this. For several reasons.
>>
>> First, it's just a cosmetic replacement for setInterval(myfunction
>> (...).bind(), ...) which simply isn't all that bad.
>>
>> Second, I'm not a fan of setInterval in general. I've seen some
>> rather nasty behavior with calls queuing up if the invoked function
>> takes longer than the delay to execute. In particular, this seems to
>> be an issue if you do something like put a laptop to sleep. (But
>> maybe others haven't seen this problem???) Thus, I prefer to use a
>> self-invoking timeout like so:
>>
>> function myFunction() {
>> // do stuff ...
>> // call ourselves again
>> if (/*we want to continue?*/) setTimeout(myFunction, 1000)
>> }
>>
>> This doesn't call the function at exactly one second intervals, but
>> that type of accuracy is rarely important. Instead, it guarantees you
>> have at least one second of delay between invocations, which for
>> distributing cpu load or polling (the more common cases where
>> setInterval might be used), is more desireable.
>>
>> Finally, as Joe T. points out, there should be a way of cancelling the
>> interval that doesn't require the user to store the returned value
>> (*that* is what I find most annoying, not the syntax of
>> "setInterval").
>>
>> Thus, I'd suggest this instead:
>>
>> Object.extend(Function.prototype, {
>> repeat: function(delay) {
>> // Reset state
>> if (this._repeater) delete this._repeater;
>> this._repeatTimeout = clearTimeout(this._repeatTimeout);
>>
>> if (!delay) return; // (stop repeating if no args or delay==0)
>>
>> // Create setTimeout-based invoker
>> var _method = this;
>> if (!this._repeater) this._repeater = function() {
>> // Let _method cancel repeat by doing "return false;"
>> if (_method() !== false) setTimeout(_method._repeater, delay);
>> }
>>
>> // Start repeating
>> this._repeatTimeout = setTimeout(this._repeater, delay);
>> },
>>
>> stopRepeating: function() {
>> this.repeat();
>> }
>> });
>>
>> For example:
>>
>> var count = 0;
>> function foo() {
>> console.log(count++);
>> return count < 10; // Return "false" when count >= 10 to cancel
>> the repeat
>> }
>>
>> // Start repeating 1/sec
>> foo.repeat(1000);
>> //... some time later change interval to 2/sec
>> foo.repeat(500);
>> // ... later still stop repeating.
>> foo.stopRepeating();
>>
>>
>> As you can see, this implementation of repeat() does a lot more for
>> you than simply alias'ing "setInterval":
>> - It guarantees your function is only invoked by one interval
>> - It makes changing the interval or cancelling it altogether
>> trivial.
>> - It allows you to conditionally cancel the repeat from w/in the
>> function itself.
>>
>> The only thing missing is the bind() behavior but, well, that's what
>> bind is for. If you need to bind arguments, just bind() your
>> arguments first.
>>
>> On Jun 23, 8:25 am, Rick Waldron <waldron.r...@gmail.com> wrote:
>> > I detest the way setInterval() looks, so I came up with this... have
>> been
>> > using it my personal JS for some time.
>> >
>> > Object.extend(Function.prototype, {
>> > repeat: function() {
>> > var __method = this, args = $A(arguments), interval = args.shift() *
>> > 1000;
>> > return window.setInterval(function() {
>> > return __method.apply(__method, args);
>> > }, interval );
>> > }
>> >
>> > });
>> >
>> > // usage:
>> > var _pollInt = 0;
>> > function repetiousPollFn() {
>> > console.log(_pollInt++);
>> >
>> > }
>> >
>> > repetiousPollFn.repeat(.5);
>> >
>> > Will, of course, repeat repetiousPollFn() every half second.
>> >
>> > Almost identical to .delay(), except that it returns setInterval instead
>> of
>> > setTimeout. One thing I intend to add is support for clearInterval,
>> however
>> > I figured I'd at least bring it up here first. I've never
>> > proposed/contributed here before (i'm a lurker of the list :D ) - any
>> > guidance is appreciated.
>> >
>> > Rick
>> >>
>>
>
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