Gator.js - simple event delegation in ~800 bytes | Hacker News Reader

Gator.js - simple event delegation in ~800 bytes

craig.is

28 pointscraigc7 comments

Why is there a Gator function when the only interface is `Gator(x).on(e, s, c)` and `Gator(x).off(e, s, c)`? Why not `Gator.on(x, e, s, c)` and rely on the caller to do partial function application (e.g. with `Function.prototype.bind`)? This seems like unnecessary memory bloat[1].

[1] https://github.com/ccampbell/gator/blob/0c8fafad45202c018706...

Probably for "chaining", like all the cool libraries do now.

    Gator
      .on(x, e1, s1, c1)
      .on(x, e2, s2, c2)
      ;

Or is chaining desired after partial application (meaning `x` is chained)?

    var onX = chainFn(Gator.on, x);
    onX
      (e1, s1, c1)
      (e2, s2, c2)
      ;

It seems that a library can provide chaining if needed.

Thanks for the comment. I considered that, but I was thinking it makes things a little cleaner/easier to maintain by using Gator objects. Only one object instance is created per element. Also it allows for chaining methods.

> Only one object instance is created per element

I think the point may be "Gator.on()" wouldn't need instances of anything allocated.

But then you lose chaining.

I see. Still, your approach leaks memory as it maintains references to nodes which may otherwise be GC'able. Have you considered `WeakMap` for caching (where supported)?

That's a good point. I probably will add some sort of destroy method. I figure in most cases with delegation you are referencing an element that is not likely to be removed (such as document), but I probably should add a way to clean up stale objects.

As for WeakMap, I wasn't even aware of that, looks awesome.

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