react-native-event-bridge-enhance.js

/**
 * react-native-event-bridge-enhance
 * @flow
 *
 */

// Mixin to provide the boilerplate that is needed for a event listener component
// as well as also supports automatic removing of subscription for event listeners
// if the listener is registered via the registerEventListener method.

import React from 'react';

import type EmitterSubscription from 'EmitterSubscription';

import EventBridge from './index';

const enhanceForEventsSupport = (ComposedComponent: React.Component<any>) => {
  const _key = 'EventsBridgeEnhance_Listeners';

  return class extends (ComposedComponent: any) {
    static contextTypes = {
      rootTag: React.PropTypes.number,
    };

    componentWillUnmount() {
      if (super.componentWillUnmount) {
        super.componentWillUnmount();
      }
      const { [_key]: listeners } = this;
      if (listeners) {
        listeners.forEach(listener => {
          listener.remove();
        });
      }
      this[_key] = null;
    }

    registerEventListener(...listeners: Array<EmitterSubscription>) {
      const { [_key]: listenerList } = this;
      if (!listenerList) {
        this[_key] = listeners;
      } else {
        listenerList.push(...listeners);
      }
      return this;
    }
  };
};

export default enhanceForEventsSupport;

/* Experimental
/********************************/
const enhanceForEventsSupportEnhanced = (ComposedComponent: any) =>
  class extends (ComposedComponent: any) {
    _subscribableSubscriptions: ?Array<EmitterSubscription>;

    static contextTypes = {
      rootTag: React.PropTypes.number,
    };

    componentWillMount() {
      this._subscribableSubscriptions = [];
    }

    componentWillUnmount() {
      if (this._subscribableSubscriptions) {
        this._subscribableSubscriptions.forEach(subscription =>
          subscription.remove()
        );
      }
      this._subscribableSubscriptions = null;
    }

    registerEventListener(callback: any) {
      if (this._subscribableSubscriptions) {
        this._subscribableSubscriptions.push(
          EventBridge.addEventListener(this, callback)
        );
      }
    }
  };

function enhanceForEventsSupportDecorator() {
  // eslint-disable-next-line func-names
  return function(DecoratedComponent: React.Component<any>) {
    const _key = 'ViewControllerEventsListenerEnhance_listeners';

    return class extends (DecoratedComponent: any) {
      static contextTypes = {
        rootTag: React.PropTypes.number,
      };

      componentWillUnmount() {
        if (super.componentWillUnmount) {
          super.componentWillUnmount();
        }
        const { [_key]: listeners } = this;
        if (listeners) {
          listeners.forEach(listener => {
            listener.remove();
          });
        }
        this[_key] = null;
      }

      registerEventListener(...listeners: Array<EmitterSubscription>) {
        const { [_key]: listenerList } = this;
        if (!listenerList) {
          this[_key] = listeners;
        } else {
          listenerList.push(...listeners);
        }
        return this;
      }
    };
  };
}

export { enhanceForEventsSupportDecorator, enhanceForEventsSupportEnhanced };