rx-subject

minimal Subject implementation (0.4k bytes gzip, no dependencies), independent of reactive framework.

a Subject exposes a sink Observer, and a source$ Subscribable. values pushed into the sink Observer are emitted by the source$ Subscribable.

the source$ Subscribable is hot and accepts any number of subscribers. all subscriptions are cleared after source$ emits error or complete.

Credits

unit tests based on the Subject test suite of RxJS.

API

this module exposes a Subject factory:

export default function createSubject<T>(): Subject<T>

export interface Subject<T> {
  sink: Observer<T>
  source$: Subscribable<T>
}

export interface Observer<T> {
  next(val: T): void
  error?(error?: any): void
  complete?(): void
}

export interface Subscribable<T> {
  subscribe(observer: Observer<T>): Subscription;
  subscribe(
    next: (val: T) => void,
    error?: (error?: any) => void,
    complete?: () => void
  ): Subscription
}

export interface Subscription {
  unsubscribe(): void
}

for a detailed specification of this API, run the unit tests in your browser. these unit tests are a subset of the RxJS Subject test suite.

Symbol.observable

This module expects Symbol.observable to be defined in the global scope. Use a polyfill such as symbol-observable and if necessary a Symbol polyfill. Check the symbol-observable-polyfill script for an example of how to generate the standalone polyfill, which can than be loaded from a script tag, or simply add import 'symbol-observable' at the top of your project's main file.

TypeScript

although this library is written in TypeScript, it may also be imported into plain JavaScript code: modern code editors will still benefit from the available type definition, e.g. for helpful code completion.

License

Copyright 2018 Stéphane M. Catala

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and Limitations under the License.