This is pretty much what I used it for in a previous job role. We loaded and unloaded various iframes, registering APIs and custom elements inside them, adding the `window` object to a WeakSet so the initialisation only ran once.
On Tue, 23 Apr 2019 at 10:26, Andrea Giammarchi <[email protected]> wrote: > WeakSet can be very useful in general to avoid *any* object to be > visited/setup twice, not just those coming from user-land classes. > > Circular references, mixins, DOM nodes one-off events handling, and so on > and so fort. > > On Mon, Apr 22, 2019 at 8:26 PM #!/JoePea <[email protected]> wrote: > >> (I edited the broken format of my previous post) >> >> What other use cases are there? >> >> On Mon, Apr 22, 2019 at 11:20 AM #!/JoePea <[email protected]> wrote: >> >>> > WeakSets are perfect for branding and are how I would expect web >>> platform class branding to be explained. >>> > >>> > ```js >>> > const foos = new WeakSet(); >>> > >>> > class Foo { >>> > constructor() { >>> > foos.add(this); >>> > } >>> > >>> > method() { >>> > if (!foos.has(this)) { >>> > throw new TypeError("Foo.prototype.method called on an >>> incompatible object!"); >>> > } >>> > } >>> > } >>> > ``` >>> >>> Just curious, is that effectively the same as what the (current) >>> [private fields proposal](https://github.com/tc39/proposal-class-fields) >>> offers? >>> >>> ```js >>> class Foo { >>> #isFoo = true >>> >>> method() { >>> if (this.#isFoo) { >>> throw new TypeError("Foo.prototype.method called on an >>> incompatible object!"); >>> } >>> } >>> } >>> ``` >>> >>> - Joe >>> >> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss >
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