upfront-editable/lib/eventable.js

Friendly contenteditable API

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = eventable;

var _jquery = _interopRequireDefault(require("jquery"));

// Eventable Mixin.
//
// Simple mixin to add event emitter methods to an object (Publish/Subscribe).
//
// Add on, off and notify methods to an object:
// eventable(obj)
//
// publish an event:
// obj.notify(context, 'action', param1, param2)
//
// Optionally pass a context that will be applied to every event:
// eventable(obj, context)
//
// With this publishing can omit the context argument:
// obj.notify('action', param1, param2)
//
// Subscribe to a 'channel'
// obj.on('action', funtion(param1, param2){ ... })
//
// Unsubscribe an individual listener:
// obj.off('action', method)
//
// Unsubscribe all listeners of a channel:
// obj.off('action')
//
// Unsubscribe all listeners of all channels:
// obj.off()
function eventable(obj, notifyContext) {
  _jquery["default"].extend(obj, getEventableModule(notifyContext));
}

function getEventableModule(notifyContext) {
  var listeners = {};

  function addListener(events, listener) {
    events.split(' ').forEach(function (event) {
      listeners[event] = listeners[event] || [];
      listeners[event].unshift(listener);
    });
  }

  function removeListener(event, listener) {
    var eventListeners = listeners[event];
    if (!eventListeners) return;
    var index = eventListeners.indexOf(listener);
    if (index < 0) return;
    eventListeners.splice(index, 1);
  } // Public Methods


  return {
    on: function on(event, listener) {
      if (arguments.length === 2) {
        addListener(event, listener);
      } else if (arguments.length === 1) {
        for (var eventType in event) {
          addListener(eventType, event[eventType]);
        }
      }

      return this;
    },
    off: function off(event, listener) {
      if (arguments.length === 2) {
        removeListener(event, listener);
      } else if (arguments.length === 1) {
        listeners[event] = [];
      } else {
        listeners = {};
      }
    },
    notify: function notify(context, event) {
      var args = Array.from(arguments);

      if (notifyContext) {
        event = context;
        context = notifyContext;
        args.splice(0, 1);
      } else {
        args.splice(0, 2);
      }

      if (this.switchContext) {
        var nextEvent = this.switchContext.events.shift();
        if (event !== nextEvent) this.switchContext = undefined;
      }

      var eventListeners = listeners[event];
      if (!eventListeners) return; // Execute the newest listeners first.
      // Stop if a listener returns false.

      eventListeners.every(function (listener) {
        return listener.apply(context, args) !== false;
      });
    }
  };
}

module.exports = exports.default;