Parameter to promise constructor

Tab Atkins Jr. jackalmage at gmail.com
Fri Aug 30 07:43:27 PDT 2013


On Fri, Aug 30, 2013 at 7:33 AM, Nathan Wall <nathan.wall at live.com> wrote:
> Domenica Denicola wrote:
>> Since there's no real advantage to the `PromiseResolver` approach, and there are a number of disadvantages, we were hoping to switch to the prevalent `(resolve, reject)` signature in the revised DOM promises spec.
>>
>> Let us know what you think!
>
>
> One advantage to the `PromiseResolver` is that it's easier to pass around than two separate functions.  Passing the resolver around isn't common, but at my workplace we've made use of it in a "requester" pattern.
>
>
>     function Requester() {
>         this.requests = Object.create();
>     }
>
>     Requester.prototype = {
>         respond: function(requestName, callback) {
>             this.requests[requestName] = callback;
>         },
>         request: function(requestName, ...values) {
>             return new Promise(resolver => {
>                 this.requests[requestName](resolver, ...values);
>             });
>         }
>     };

Just change this to:

    this.requests[requestName]({resolve, reject}, ...values);

Changing the argument signature has only a tiny, local effect on your code.

~TJ


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