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    symbol-observable
    TypeScript icon, indicating that this package has built-in type declarations

    4.0.0 • Public • Published

    symbol-observable Build Status

    Symbol.observable pony/polyfill

    This will polyfill Symbol.observable if Symbol exists, but will not polyfill Symbol if it doesn't exist. Meant to be used as a "ponyfill", meaning you're meant to use the module's exported symbol value as described below. This is all done to ensure that everyone is using the same version of the symbol (or string depending on the environment), as per the nature of symbols in JavaScript.

    Install

    $ npm install --save symbol-observable
    

    Basic Usage

    const symbolObservable = require('symbol-observable').default;
    
    console.log(symbolObservable);
    //=> Symbol(observable)
    import Symbol_observable from 'symbol-observable';
    
    console.log(Symbol_observable);
    //=> Symbol(observable)

    Making an object "observable":

    You can do something like what you see below to make any object "observable" by libraries like RxJS, XStream and Most.js.

    Things to know:

    1. It's best if you just use one of the above libraries.
    2. If you're not, but sure you never next, error or complete on your observer after error or complete was called.
    3. Likewise, make sure you don't next, error or complete after unsubscribe is called on the returned object.
    import Symbol_observable from 'symbol-observable';
    
    someObject[Symbol_observable] = () => {
      return {
        subscribe(observer) {
          const handler = e => observer.next(e);
          someObject.addEventListener('data', handler);
          return {
            unsubscribe() {
              someObject.removeEventListener('data', handler);
            }
          }
        },
        [Symbol_observable]() { return this }
      }
    }

    Often, it's not very hard, but it can get tricky in some cases.

    Related

    License

    MIT © Sindre Sorhus and Ben Lesh

    Install

    npm i symbol-observable

    DownloadsWeekly Downloads

    12,748,537

    Version

    4.0.0

    License

    MIT

    Unpacked Size

    16.8 kB

    Total Files

    12

    Last publish

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