jjb-lc-designable/shared/subscribable.js

基于alibaba-designable源码二次封装的表单设计器。

import { isFn } from './types';
const UNSUBSCRIBE_ID_SYMBOL = Symbol('UNSUBSCRIBE_ID_SYMBOL');
export class Subscribable {
  subscribers = {
    index: 0
  };
  dispatch(event, context) {
    let interrupted = false;
    for (const key in this.subscribers) {
      if (isFn(this.subscribers[key])) {
        event['context'] = context;
        if (this.subscribers[key](event) === false) {
          interrupted = true;
        }
      }
    }
    return interrupted ? false : true;
  }
  subscribe(subscriber) {
    let id;
    if (isFn(subscriber)) {
      id = this.subscribers.index + 1;
      this.subscribers[id] = subscriber;
      this.subscribers.index++;
    }
    const unsubscribe = () => {
      this.unsubscribe(id);
    };
    unsubscribe[UNSUBSCRIBE_ID_SYMBOL] = id;
    return unsubscribe;
  }
  unsubscribe = id => {
    if (id === undefined || id === null) {
      for (const key in this.subscribers) {
        this.unsubscribe(key);
      }
      return;
    }
    if (!isFn(id)) {
      delete this.subscribers[id];
    } else {
      delete this.subscribers[id[UNSUBSCRIBE_ID_SYMBOL]];
    }
  };
}