Event Emmiter

event-handler.js

import storeUpdates from './storeUpdates';

export const STORE = {
  ACTION_STORE: {
    count: 999,
    init: false,
  },
  DATA_STORE: {},
  func: {
    emit: (key, data) => {
      if (STORE.ACTION_STORE[key]) {
        // check the action is in the store
        for (let i in STORE.ACTION_STORE[key]) {
          // call all the functions that are define under the key
          STORE.ACTION_STORE[key][i].fn(data || undefined);
        }
      }
    },

    // add listeners
    on: (key, fn) => {
      if (STORE.ACTION_STORE[key]) {
        // check store has that key already
        // push to actions array
        STORE.ACTION_STORE[key].push(
            { key: ++STORE.ACTION_STORE.count, fn }
          );
      } else {
        // create action array
        STORE.ACTION_STORE[key] = [
            { key: ++STORE.ACTION_STORE.count, fn }
          ];
      }
      return STORE.ACTION_STORE.count;
    },

    // clear the listeners from the action store.
    clear: (obj) => {
      Object.keys(obj).forEach((k) => {
        STORE.ACTION_STORE[k] = STORE.ACTION_STORE[k]
          .filter(({ key }) => !obj[k].includes(key));
      });
    },

    init: () => {
      !STORE.ACTION_STORE.init && storeUpdates();
    },
  },
};

export const createStoreUpdater = (actionName, key) => {
  STORE.func.on(actionName, (data) => {
    STORE.DATA_STORE[key] = data;
  });
};

export const setInitStore = (obj) => {
  STORE.DATA_STORE = obj;
  STORE.ACTION_STORE.init = true;
};